ELECTRICAL & COMPUTER

FACULTY OF ENGINEERING

VACATION INTERNSHIP REPORT

Name of Student: ____Hou Liwen

___ Matric No. _A0105595B

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Course/Year/Training Period: ___Electrical Engineering/2014/12/5-1/8 Student’s Email Address: __A0105595@NUS.EDU.SG Name of Mentor: __Chen Zhi Ning_____ Name of Company: __Surbana Technologies Pte Ltd _____ ______

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Vacation Internship Report 2
AT

Surbana Technologies Pte. Ltd.
Reporting Period:

23/06/2014-01/08/2014

Submitted by:

Hou Liwen A0105595B

Dept/Year of Studies Department of Electrical and Computer Engineering The National University of Singapore 2014

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TABLE OF CONTENTS Page ACKNOWLEDGMENTS I INTRODUCTION II THE TRAINING ASSIGNMENTS III CONCLUSION Student Feedback form Student Log Sheet VIP Report Clearance Form 4 5 6 23 24 26 27

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ACKNOWLEDGMENTS The vacation internship program is a golden opportunity for learning and self-development. I consider myself very lucky and honored to have such a wonderful opportunity to be an intern at Surbana Technologies Pte. Ltd and have so many helpful knowledgeable people lead me through in completion of my internship program. I wish to express my indebted gratitude and special thanks to Mr Louis Tay who in spite of being extraordinarily busy with his duties, took time out to hear, guide and keep me on the correct path and allowing me to carry out my internship at his esteemed organization. I do not know where I would be without him. I also want to express my deepest thanks to Mr Raymond Seah Yew Teck and Mr Alan Lee Kok Wah for teaching me the essential concepts of the projects and giving necessary advices and guidance and arranged all facilities to make life easier. I choose this moment to acknowledge their contribution gratefully. I express my deepest thanks to Ms Cindy Yap and Ms Yvonne for arranging suitable position for me in the team and providing advice when I was lost about my job.

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I INTRODUCTION Surbana is an award-winning international urbanisation consultant, offering full-service building consultancy solutions, including integrated sustainable design solutions in architecture, engineering, quantity surveying, project and construction management, coastal engineering, infrastructure and land survey, urban planning, building technology and city management. Over the last 50 years, Surbana had successfully planned, designed and completed more than a million homes across 26 townships, and reclaimed almost 10% of the island, providing holistic living environments that incorporated a breadth of amenities such as parks, schools, mixed-use developments, roads and commercial projects for over 80% of the population. Surbana’s roots can be traced back to the 1960s when it was the Building and Development Division of the Housing & Development Board (HDB). Housing & Development Board (HDB) was established as a government agency to solve Singapore’s housing crisis and to provide affordable and quality housing for the growing population. Born out of the need to alleviate Singapore’s severe housing shortage, HDB had successfully created a world-class public housing model which has re-defined the standards of superior and affordable living spaces. In July 2003, HDB’s Building and Development Division was corporatised as HDB Corporation Pte Ltd (HDBCorp) in a bid to export Singapore’s decades of urbanisation expertise and experience to other countries. In the same year, it started to venture into the China market. A year later, the potential of HDBCorp was evident in its acquisition by Temasek Holdings, the Singapore Government’s investment vehicle and in 2005, the company was rebranded as Surbana Corporation Pte Ltd. Later in April 2011, CapitaLand, one of the largest real estate developers in Singapore, acquired a 40% stake in Surbana, with the rest held by Temasek Holdings. Two years later, Surbana underwent a restructure and its township development arm, Surbana Land was integrated with CapitaLand China, leaving its consultancy as the core business for Surbana. Under Surbana Corporation Pte Ltd, Surbana Technologies Pte Ltd has over 20 years of know-how in providing real-time monitoring of building services and estate management solutions for townships. they have build up a niche in customizing cost-effective solutions to facilitate 5

maintenance tenancy, security surveillance, supply chain & inventory, equipment & plant, as well as car park management for large township developments. Their comprehensive range of services also includes technology consultancy on townships and facilities management, energy and environmental issues, as well as performance-based management systems. The team I am assigned to is lead by Mr Raymond Seah Yew Teck and is dedicated to the Performance Enhancement Lighting Management System (PELMSTM).

II THE TRAINING ASSIGNMENTS Performance Enhancement Lighting Management System Artificial lighting consumes a significant amount of energy. It is reported that about 40% of commercial electrical energy is used for lighting. Among the energy that is used for lighting, up to 90% can be wasted due to over illumination, that is, the light is still on when the occupancy is low or even no one is there. A lot of lighting technologies are developed over the years to save energy such as compact fluorescent light, light emitting diode, and occupancy sensor that turns on the light when movement, sound or heat is detected. However, drawbacks exist. For example, compact fluorescent lights are not dimmable and not suitable for outdoor use. Light emitting diode are of low brightness. That means more light bulbs will be needed to reach the same illumination. And the expense of LED light remains high. The conventional occupancy sensor is not accurate. It will affected by the surrounding environment. Also, it normally only comes with the on and off options, but not dimming options. PELMSTM is an innovative energy saving solution created by Surbana Technologies Pte Ltd in collaboration with Singapore Polytechnic. It is the simplest and most advanced way of managing building’s lighting infrastructure of linear or compact fluorescent lightings and it is the optimal way to save energy. The PELMS consists of three parts: the sensor, the controller, and the reflector. The major breakthrough with PELMS centres around a patent pending controller device called “Ultimate Saver”. Currently PELMS works on linear & Compact Fluorescent Lighting either with magnetic ballast or HF ballast. The smaller USC is also a very much smarter chip. Its intelligent capabilities 6

allow PELMS to set new performance benchmarks for Intelligent Lighting. User can set the power setting at 'Full' and 'Energy Saving' mode as well the power setting on these modes with further instruction to turn off the power if desired to achieve more energy savings. The PIR SMART SENSOR powers the Performance Enhancing Lighting Management System by providing granular control of the environment without a centralized controller. Smart Sensors are deployed at every fixture where they sense occupancy and manage the lights to vary in the illumination levels as set by the user requirements. The real-time information gathered by each sensor is passed to the Ultimate Saver to allow power control to the lighting output. The Dimming Ballast here as part of the whole provision comes in 2 forms. Either a magnetic or electronic depending on the type of lighting system you are using. The Ultimate Saver will control the output power through the dimming ballast, which will allow power control to the lighting output. The success of PELMS is due to the accurate detection of the sensor and the automatic power control of the Ultimate Saver. Traditional lighting occupancy control strategies uses zone rather than individual control thus turning on all the lights methods by controlling lightings in a zone even with a single person present hence yielding lower energy savings. PELMS’s approach however ensures high-energy savings because each individual light has built in intelligence to truly correlate vacancy and occupancy in its detection space.Each Ultimate Saver fitted in lighting fixture is programmed with user pre-set requirement the time delay to dim as well as how much to dim after the Passive Infra Red Sensor (PIR) detects no occupancy. Ultimate Saver will accordingly power up lighting fixtures to the full power (FULL MODE) upon the PIR detecting occupancy. Under a preset time delay, when the Ultimate Saver acknowledged a no occupancy status it will power down or turn off the lighting fixture (Energy Saving Mode). After getting familiar with the concept of the system, I visited NEX mall at Serangoon MRT to meet with the Operation Manager and saw my supervisor negotiating about the implement of PELMS in NEX with the manager. I have also analysed the storey plan of NEX and helped with calculating the cost of implementing PELMS in NEX. Other few site visiting includes Leonie Condotel near River Valley and Orchard Parade Hotel. There, I helped with the implementing of PELMS to one circuit of light in the car park to see the energy saving. I have done a presentation on PELMS to my supervisor. I also studied the energy saving report on PELMS at JTC Corporation.

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At week 6, I visited headquarter of National Energy Authority to attend the meeting with their personnel and saw my supervisor present PELMS to them and analyse the place to install PELMS.

Figure 1. Installation of PELMS For the second part of the internship, I was assigned to the group that dedicated to the Lift Management System in all the HDB blocks in Singapore. Currently, the lifts are undergoing upgrading. The responsibility of the group that I was assigned to was to test the functionality of the lift management system, which can monitor all the lifts through the master station in Surbana Technologies Pte Ltd. Lift Monitoring System The Tele Monitoring System is realized through the lift management device that is installed at the top of each lift. They communicate through antenna and telephone line provided by SingTel. The Tele Monitoring System has been implemented on all HDB lifts, and all lifts must be linked to this system. This system gathers information from the lifts and with this information, conditions such as 8

lift breakdowns, passenger traps, power failure, lift maintenance as well as other types of conditions can be detected. The control of the lift is achieved by an integrated chip RS485. Below is the internal connection of the chip.

Figure 2. Internal Connection of RS485 RS-485 enables the configuration of inexpensive local networks and multidrop communications links. It offers data transmission speeds of 35 Mbit/s up to 10 m and 100 kbit/s at 1200 m. Since it uses a differential balanced line over twisted pair (like RS-422), it can span relatively large distances (up to 4,000 feet (1,200 m)). A rule of thumb is that the speed in bit/s multiplied by the length in meters should not exceed 108. Thus a 50 meter cable should not signal faster than 2 Mbit/s. In contrast to RS-422, which has a single driver circuit which cannot be switched off, RS-485 drivers need to be put in transmit mode explicitly by asserting a signal to the driver. This allows RS-485 to implement linear bus topologies using only two wires. The equipment located along a set of RS-485 wires are interchangeably called nodes, stations or devices. The recommended arrangement of the wires is as a connected series of point-to-point (multidropped) nodes, i.e. a line or bus, not a star, ring, or multiply connected network. Ideally, the two ends of the cable will have a termination resistor connected across the two wires. Without termination resistors, reflections of fast driver edges can cause multiple data edges that can cause 9

data corruption. Termination resistors also reduce electrical noise sensitivity due to the lower impedance, and bias resistors (see below) are required. The value of each termination resistor should be equal to the cable characteristic impedance (typically, 120 ohms for twisted pairs). Star and ring topologies are not recommended because of signal reflections or excessively low or high termination impedance. If a star configuration is unavoidable, such as when controlling multiple pan tilt zoom cameras from a central video surveillance hub, special RS-485 star/hub repeaters are available which bidirectionally listen for data on each span and then retransmit the data onto all other spans.

Somewhere along the set of wires, pull up or pull down resistors are established to fail-safe bias each data wire when the lines are not being driven by any device. This way, the lines will be biased to known voltages and nodes will not interpret the noise from undriven lines as actual data; without biasing resistors, the data lines float in such a way that electrical noise sensitivity is greatest when all device stations are silent or unpowered. RS-485 only specifies electrical characteristics of the generator and the receiver. It does not specify or recommend any communications protocol, only the physical layer. Other standards define the protocols for communication over an RS-485 link. The foreword to the standard recommends The Telecommunications Systems Bulletin TSB-89, which contains application guidelines, including data signaling rate vs. cable length, stub length, and configurations. Section 4 defines the electrical characteristics of the generator (transmitter or driver), receiver, transceiver, and system. These characteristics include: definition of a unit load, voltage ranges, open circuit voltages, thresholds, and transient tolerance. It also defines three generator interface points (signal lines); "A", "B" and "C". The data is transmitted on "A" and "B". "C" is a ground reference. This section also defines the logic states 1 (off) and 0 (on), by the polarity between A and B terminals. If A is negative with respect to B, the state is binary 1. The reversed polarity (A +, B-) is binary 0. The standard does not assign any logic function to the two states. Often in a master-slave arrangement when one device dubbed "the master" initiates all communication activity, the master device itself provides the bias and not the slave devices. In this configuration, the master device is typically centrally located along the set of RS-485 wires, so it would be two slave devices located at the physical end of the wires that would provide the termination. The master device itself would provide termination if it were located at a physical end of the wires, but that is often a bad design as the master would be better located at a halfway point 10

between the slave devices, to maximize signal strength and therefore line distance and speed. Applying the bias at multiple node locations could possibly cause a violation of the RS-485 specification and cause communications to malfunction.

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The functionality of the lift are specified by the output voltage of the pin points on the RS485 chip. The details are shown below.

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IV CONCLUSION During the first part of my 12-week internship, I have immersed the the real workplace and learnt to communicate with people from different parties. I have also learnt a bit about project management and how to present a product to customers. I have learnt the skills to utilize tools during the installation of the lighting system and how to protect myself from electricity. I have also learnt some programming skills in control system. Overall, it is an enriching experience to me and I really look forward to the next half of my internship.

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Most of the points as shown in the tables are self-explanatory. Points which need further elaboration are found hereunder: P10 – LMDC Switch, P11 – RO Switch: When the key is in the Normal position, P10 and P11 input shall be low. When the key is turned, P10 or P11 input shall be high. This key can only be removed after the personnel leave the machine room. Both keys shall be mounted at the TMS closet. Both key switches shall be subjected to the approval of SO Rep. P12 – LM Switch: When the key operated switch is in the Normal position, P12 input shall be low. When the key operated switch is in the Maintenance position, P12 input shall be high and it shall disable the remote switching off of lift by TMS. P13 – Machine Room Door Magnetic Switch: This switch is to detect the opening of the machine room door. The switch shall consist of two parts, one part shall consist of a contact, formed by a reed switch, and the other part is a permanent magnet. The two parts shall be installed, one part at the top part of the door, the other part on the lintel. The switch shall have a rating of at least 1A. As the lift machine room has only one door and sometimes there are more than one lift in the machine room, the contractor shall wire the magnetic switch to P13 of the A lift (or the lift of the smallest alphabetical order) of the machine room. All other lifts in the same machine room shall have the P13 points tied to the negative of EBOPS battery terminals. The cables from the terminal blocks to the switch shall be run in separate trunking to ensure that there is no interference from other cables. If this is not possible, screen cables shall be used for the said point. P15, P16, P17 – Power Supply Detection: Three relays designated as R1, R2, R3 shall be used to sense the power supply to the lift. Each of these relays shall sense a line to line voltage at 3 different locations. P30, P31, P32, P34 – 4 Bits Error Code: There four points represent in binary code any lift faults occurring on the lift. There 4 bits shall not be the same as the breakdown codes of the lift, but shall only represent final breakdown codes. Condition A. P34 0 P32 0 P31 0 P30 1. Any safety device tripped. Condition B. P34 0 P32 0 P31 1 P30 0. Lift door opening problem. Door failed to open at landing after two attempts, error code is issued after which; lift move to the another landing to try and so on; the error code cannot be cleared unless the doors can open at landing where the problem occurred. 15

Condition C. P34 0 P32 0 P31 1 P30 1. Lift speed controller failure. Lift manufacturer to advice. Condition D. P34 0 P32 1 P31 0 P30 0. Any hall button jammed. Landing button either up or down jammed for three minutes after which; error code is issued. Lift move to the other landings. The fault code shall be set till the jammed button is cleared. Condition E. P34 0 P32 1 P31 0 P30 1. MIC board failure. Auxilary board failed. Condition F. P34 0 P32 1 P31 1 P30 0. Reverse phase or under-voltage. Under or over voltage, reverse phase or one phase no supply occurred. If the fault is restored, the lift shall resume normal operation and the error code shall be cleared. Condition G. P34 0 P32 1 P31 1 P30 1. Lift door closing problem. If the door cannot close due to the object stuck in the sill or other reasons, the lift shall try to close the door. After trying unsuccessfully to close the door for 4 times, the lift shall be parked with the door open and all outstanding car calls cancelled. The lift shall not be shut down. Subsequently if a new car call is registered, the lift shall try to close the door for another 4 times, failing which the lift shall again be parked with door open and all car calls cancelled. This process shall be repeated. If after 10 minutes the door still cannot close the error code shall be set. Even thought the error code is set, the lift shall continue to try to close the door if a car call is registered as explained above. If the lift is successful in closing the door, the error code shall be reset and the lift shall resume normal operation; Safety edge is jammed for ten minutes or infra-red beam is broken, the error code shall be set. Lift shall be taken out of group control if applicable but shall not be shut down. After fault has been cleared and there is new car call registered, lift should resume normal operation and error code should be cleared; in the event the curtain sensor is blocked for more than 1 seconds, it shall be ignored. Buzzer shall then sound and door stars to close using nudging speed. If safety edge is activated during closing of the door, the door shall stop closing and re-open. If safety edge is not activated during door closing and the door is not obstructed, the door shall continue to close at nudging speed until it is fully closed, and thereafter the lift shall move in response to the car call registered. If the door fails to close fully at nudging speed after 2 attempts, the lift shall be parked with the door open and all outstanding car calls cancelled. The lift shall not be shut down. Subsequently if a new car call is registered, the lift shall try to close the door for another 2 attempts, failing which the lift shall again be parked with door open and all car calls cancelled. This process shall be repeated. If after 10 minutes the door still cannot close, the error code shall be set. Even though the error code is set the lift shall continue to try to close the door if a car call is registered. If the lift is successful in closing the door the error code shall be reset and the lift shall resume normal operation.

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The details of the Tele-Monitoring System of the HDB lifts are descripted above. The images below shows how the system is mounted for lifts in the HDB blocks.

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One interesting feature of the lift monitoring system is that it can detect urine. The urine-detecting device is mounted inside the lift car all around. Once urine is detected, the passenger will be trapped in the lift and the alarm in the town council office will ring. Below is the design and the inner connection of the device.

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My job is to follow the officer to meet the contractor from the chip company and the lift company at the HBD blocks, where the test is conducted. After the test, there would be handover from Surbana to town council. Research on Smart City Surbana is a leading company in providing consultation to city management. In order to develop its market in China, it is currently doing research on Smart City. Urban performance currently depends not only on the city's endowment of hard infrastructure ('physical capital'), but also, and increasingly so, on the availability and quality of knowledge communication and social infrastructure ('intellectual capital and social capital'). The latter form of capital is decisive for urban competitiveness. It is against this background that the concept of the smart city has been introduced as a strategic device to encompass modern urban production factors in a common framework and to highlight the growing importance of Information and Communication Technologies (ICTs), social and environmental capital in profiling the competitiveness of cities. The significance of these two assets - social and environmental capital itself goes a long way to distinguish smart cities from their more technology-laden counterparts, drawing a clear line between them and what goes under the name of either digital or intelligent cities. Smart(er) cities have also been used as a marketing concept by companies and by cities. A city can be defined as ‘smart’ when investments in human and social capital and traditional (transport) and modern (ICT) communication infrastructure fuel sustainable economic development and a high quality of life, with a wise management of natural resources, through participatory action and engagement. To Gildo Seisdedos Domínguez, the smart city concept essentially means efficiency. But efficiency based on the intelligent management and integrated ICTs, and active citizen participation. Then implies a new kind of governance, genuine citizen involvement in public policy. Smart cities can be identified (and ranked) along six main axes or dimensions: These six axes connect with traditional regional and neoclassical theories of urban growth and development. In particular, the axes are based - respectively - on theories of regional competitiveness, transport and ICT economics, natural resources, human and social capital, quality of life, and participation of citizens in the governance of cities.

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It insists that smart cities are defined by their innovation and their ability to solve problems and use of ICTs to improve this capacity. The intelligence lies in the ability to solve problems of these communities is linked to technology transfer for when a problem is solved. In this sense, intelligence is an inner quality of any territory, any place, city or region where innovation processes are facilitated by information and communication technologies. What varies is the degree of intelligence, depending on the person, the system of cooperation, and digital infrastructure and tools that a community offers its residents. The concept of the smart city as the next stage in the process of urbanisation has been quite fashionable in the policy arena in recent years, with the aim of drawing a distinction from the terms digital city or intelligent city. Its main focus is still on the role of ICT infrastructure, but much research has also been carried out on the role of human capital/education, social and relational capital and environmental interest as important drivers of urban growth. The European Union (EU), in particular, has devoted constant efforts to devising a strategy for achieving urban growth in a smart sense for its metropolitan city-regions. Other international institutions and thinktanks also believe in a wired, ICT-driven form of development. The Intelligent Community Forum produces, for instance, research on the local effects of the worldwide ICT revolution. The OECD and EUROSTAT Oslo Manual stresses instead the role of innovation in ICT sectors and provides a toolkit to identify consistent indicators, thus shaping a sound framework of analysis for researchers on urban innovation. At a mesoregional level, we observe renewed attention for the role of soft communication infrastructure in determining economic performance. The availability and quality of the ICT infrastructure is not the only definition of a smart or intelligent city. Other definitions stress the role of human capital and education and learning in urban development. It has been shown, for example,[9][10] that the most rapid urban growth rates have been achieved in cities where a high share of educated labour force is available. Innovation is driven by entrepreneurs who innovate in industries and products which require an increasingly more skilled labour force. Because not all cities are equally successful in investing in human capital, an educated labour force – the 'creative class' – is spatially clustering over time. This tendency for cities to diverge in terms of human capital has attracted the attention of researchers and policy makers. It turns out that some cities, which were in the past better endowed with a skilled labour force, have managed to attract more skilled labour, whereas competing cities failed to do so. Policy makers, and in particular European ones, are most likely to attach a consistent weight to spatial homogeneity; in these circumstances the progressive clustering of urban human capital is then a major concern. 21

Wireless sensor networks is a specific technology that helps to create Smart Cities. The aim is to create a distributed network of intelligent sensor nodes which can measure many parameters for a more efficient management of the city. The data is delivered wirelessly and in real-time to the citizens or the appropriate authorities. For example, citizens can monitor the pollution concentration in each street of the city or they can get automatic alarms when the radiation level rises a certain level. It is also possible for the authorities to optimize the irrigation of parks or the lighting of the city. Water leaks can be easily detected or noise maps can be obtained. Rubbish bins can send an alarm when they are close to being full. Vehicle traffic can be monitored in order to modify the city lights in a dynamic way. Traffic can be reduced with systems that detect where the nearest available parking slot is. Motorists get timely information so they can locate a free parking slot quickly, saving time and fuel. This information can reduce traffic jams and pollution improve the quality of life. It has also been recently asserted that, due to the revenue-generating nature of parking, smart parking systems could be the ideal foundation for building municipal wireless networks. These sensing networks could later be extended to include other types of sensing, as California-based company Streetline announced it would offer in early 2014, adding road surface temperature and noise sensing capabilities to its smart parking portfolio. Combined sewer overflow (CSO) events can be mitigated by using distributed rainwater harvesting infrastructure to reduce peak flows and maximize wet weather capture. This enables wastewater treatment facilities to treat stormwater runoff rather than it being flushed to the receiving water body. On December 5, at the Annual Meeting of the 2012 Chinese Smart City Development, sponsored by the Informatization Research Center of the Chinese Academy of Social Sciences (CIS) and other institutions, Wuxi ranked first with a total score of 71.2 in national smart cities. Reportedly, after the evaluation of a scientific target system and experts, Wuxi had received this honor owing to the steady implementation of the intelligence industry and intelligence infrastructure, solid management base, outstanding abilities of the government's services, application of models, advanced construction of organizational systems and other aspects. Zhang Keping, Director of the Wuxi Municipal Informatization and Radio Administration, stated that urbanization and informatization are the development themes in recent times. The idea of "Smart Cities" is a new mode for modern urban development and is an advanced phase for informatization development of cities. Intelligence has become a common choice and necessary trend for Chinese cities' development. Wuxi will make use of the information technology, strengthen the city governance ad environmental construction, promote services for the people's livelihood and 22

industrial development, and provide a better living environment for citizens, thus achieving a beautiful prospect as a smart city. III CONCLUSION During my 12-week internship, I have immersed in the real workplace and learnt to communicate with people from different parties. I have also learnt a bit about project management and how to present a product to customers. I have learnt the skills to utilize tools during the installation of the lighting system and how to protect myself from electricity. I have also learnt some programming skills in control system. Overall, it is an enriching experience to me and I really look forward to the next half of my internship.

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National University of Singapore Faculty of Engineering EG3602 Vacation Internship Program Student Feedback Form Please fill in the form diligently and ensure that it is attached at the back of your VIP Report 2 before uploading onto the web. 1. General Information: Hou Liwen A0105595B Computer and Electrical Engineering 12/5/2014-1/8/2014 Faculty / Self-initiated

Student's Name: Matriculation No.: Department: Period of Attachment: Internship Category: 2. Feedback on Company:

Company's Name: Department student was attached to:

Surbana Technologies Pte Ltd Aviation & City Management

Describe briefly nature of work performed: Performance Enhancement Lighting Management System; Lift Monitoring System; Research on Smart City Was nature of work assigned challenging? Yes / No If not, please elaborate:

Comment briefly on level of supervision provided: Supervisors are helpful and kind. They provided guidance and knowledge. Would you recommend your peers/juniors to intern with this company in future? Yes / No

Suggest ways in which you think the Vacation Internship Program offered by the company could be improved: No Overall, how do you rate your internship experience with this company? If poor, please elaborate: Excellent / Good / Satisfactory / Poor

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Allowance Paid 3. General Feedback (optional):

$ 800/mth

Suggest ways in which you think the Vacation Internship Program, as a whole can be improved:

Date: 23 August 2014 Signature of Student: Hou Liwen

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