• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1445-1456
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• 2011

This paper presents the research of Low Pass Filter(hereinafter called "LPF") which is the part of Chopper Gate Control Unit on the electric rolling stock. Chopper Gate Control Unit controling the propulsive equipments of electric rolling stock consists of several electronic parts, PCB, Power Supply, Gate Circuit Amp, Freon Cooling Device, and has been used the parts made by japan manufacturer Mitsubish. But these parts recently have been more broken down and slow down performance because of long-term use, deterioration. Most of the malfunctions are low performance of LPF. Furthermore, it is physically impossible to repair LPF. Because it is molding type part and no longer manufactured. Also it needs high cost for custom-building. Therefore, it is now making up for through self-developed LPF and operating on Busan metro 1st after on-board testing. This research performed the PS Pice simulation testing, analysis of self-developed LPF performance and the wave form characteristic by multi-function synthesizer, spectrum analyzer, oscilloscope.

• Journal of Practical Engineering Education
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• v.5 no.2
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• pp.123-127
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• 2013

Youth employment academy program focuses on resolving the job mismatch of youth unemployment through industry oriented human resource development for which company oriented capacity building program for graduate-to-be and graduate is supported. One of the major characteristics of this program is to use the M-to-M model with common skills for companies of same type of business. The operation organization in youth employment academy is supposed to be evaluated by the final employment rate after 1 year and 6 months since start of the program. So performance indicator for the operation organization was developed which means a kind of mid-term evaluation. In this research, the validity of the performance indicator is discussed. The correlations between the performance indicator and the performance evaluation, between the performance evaluation and the final employment rate, and between the performance indicator and the final employment rate are analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.744-749
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• 2016

This paper presents the design of a computer-generated hologram for beam control of an LCOS-based wavelength selective switch, which is the core technology for next-generation ROADM. By introducing a computer-generated hologram instead of general grating patterns to control the LCOS device, we contribute to building a more efficient wavelength selective switch. With the use of phase modulation properties of LCOS devices, we designed the hologram for five-port output and a 40-channel wavelength selective switch. We applied a multi-level phase modulation technique with the Gerchberg-Saxton algorithm to produce the hologram, which is easily scalable to any different type of wavelength selective switch. With an experimental setup, we verified the usability of the hologram designed for five-port output. We also suggest a hologram design technique for beam control of a 40-channel wavelength selective switch.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.325-337
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• 2014

The research on the actual condition of indoor asbestos concentration in Korea has not been thoroughly accomplished up to now. In this research the ratio of asbestos-containing buildings and indoor asbestos concentration was studied. This investigation was conducted in 2012 and 2013 and buildings were categorized based on region, building type by use, existing space(ground or basement), and construction year, respectively. Also the indoor asbestos concentration change was monitored to evaluation the efficiencies of two types of asbestos-concentration abatement devices. As a result, the ratio of asbestos-containing buildings in Seoul was largely decreased. The ratio of asbestos-containing buildings was higher in hospitals and schools regionally and in ground buildings than in basement. The average indoor asbestos concentrations were 0.0011, 0.0008 piece/cc in 2012 and 2013 investigation, respectively. Those values were much lower than standards(0.01 piece/cc), therefore the threat of indoor asbestos concentration might be negligible. In asbestos-concentration abatement experiments, the circulation velocity of ventilator were changed 2-6.7 m/sec. With 6.7 m/sec of velocity of ventilator, the concentration of indoor asbestos was fluctuated and maximum value was 2.4 piece/cc. With 4.5 and 2 m/sec of velocities of ventilator, the maximum concentration of indoor asbestos was fluctuated and maximum value was 0.9 piece/cc. This indicated that the concentration of indoor asbestos was decreased partly due to the free drop of asbestos. From these results, the proper velocity of ventilator seems to be between 4.7 and 6.5m/sec under this circumstance and further research is required. These research results may be used to guideline of asbestos management policy.

• International Journal of Concrete Structures and Materials
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• v.10 no.sup3
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• pp.97-108
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• 2016

When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is regarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties of energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and air content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened concrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS 3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica fume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson's ratios. On the other hand, the compressive strength and splitting tensile strength decreased with increasing fly ash.

• Korean Institute of Interior Design Journal
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• v.14 no.2 s.49
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• pp.112-119
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• 2005

This study attempts to suggest new directions of urban multi-family housing design in the recent era of information, in which the representation of publicity and privacy of the housing reflects new meanings and relationships of the current digital society. The study examines cases of Dutch multi-family housing and investigates the meanings and relationships of publicity and privacy in the building as well as unit design of the housings. Borneo-Sporenburg housing development is a good example that suggests new interpretation and design solution for low-rise, high-density multi-family housing. Thus, this study analyzes street patterns, facade design, and ways of housing unit combination in Borneo-Sporenburg housing and concludes as follows. First, public space in Borneo-Sporenburg housing, which was designed differently from hierarchical and centripetal organization of modern architecture, is divided into small units and spread into the inside, which provides high potential for personal control of space and personal programming of space by space choices. Second, street pattern and facade design of Borneo-Sporenburg housing provide visual publicity and privacy simultaneously as they maintain unity as a whole as well as articulate individual unit in many different ways and provide clues to neighboring. Streets as a public domain have self-controlled boundaries for residents and introduce voluntary use-programs for residents. Third, facades of the housing have no inter-mediate space or common space, and confront streets directly. Space in-between is composed inside the facade and extends into the streets by residents' own choices. Fourth, privacy and individuality of the housing is strengthened. Units of the housing have individual entrances, unique plan type and complicated combination of space that all together emphasize individuality of units, however they are not often notified from the outside.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.47-54
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• 2015

PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at $25^{\circ}C$ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

• Journal of Korean Society of Steel Construction
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• v.24 no.3
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• pp.313-323
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• 2012

The purpose of this study is to evaluate $CO_2$ reduction and the flexural performance of steel wire-integrated void deck plate slabs that were inserted in omega-shaped steel plates to reduce concrete and welded H-section beams. The void deck plate slab can secure the structure, not only reducing the weight of the building but it is also eco-friendly. Therefore, this study evaluated the flexural performance of the composite beam by conducting a monotonic loading test with the use of actuators. It quantitatively evaluated the $CO_2$ emission based on earlier studies. The main test parameters are the concrete thickness of upper slabs, and the interrupted width of the omega-shaped steel plate. The result of the test showed that the welded H-section beam applied steel wire-integrated void deck plate slabs that were inserted into the omega-shaped steel plate declined in flexural performance on the composite beam after reducing concrete volume. Likewise, it is effective in reducing $CO_2$.

• Journal of architectural history
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• v.3 no.2 s.6
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• pp.142-156
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• 1994

This paper aims to study on the periodical competition, the program, the jury organization, the reward, and copyright applied to the buildings which were constructed with architectural design competition performed in European and American region between 19c and 20c. The results of this study are as follows; 1. Befor 1900 Period, the type of buildings added to the competition program; between 1900 period and 1950 period, the works of strong nationality and rich local color were preferred; After 1950 period, the design drawings of high symbol and function were chosen 2. There are three types of design competitions: the open design competition, the invited and limited design competition, and the idea design competition. The open design competition has been most often made. 3. The juries were, most of all, composed of professional architects over 30 percent. 4. The program was written about building scale and appointments, described what form drawings, brief notes and air perspective wood have to be submitted. For instance, the use of colour was not permitted in the drawings, as this might possibly mislead the jurors. 5. The reward was given to the winners; the copyright was given to the first prize winner. 6. The standard of entry's qualification was mostly architect 7, Entry term was from a minimum month to a maximum year after annoncement of competition, it was approximetly 63% between 4 months and 8 months. I am convinced that architect gets freedom of pure creation and joy of society service through competition, architect justifies his profession and keep his useful and creative effort to society constantly, as long as the competition exists.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.507-514
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• 2006

Various application systems are developed using RFID as a part of ubiquitous computing, and it is expected that RFID chip will become wide-spread for the distribution industry especially. Efficient and efact intelligent-type of warehouse management system is essential for small-to-medium-sized enterprises in the situation having a trouble in the viewpoint of expense and manpower. In this paper, we implement small-scale warehouse management system using log-based context awareness technology. This system is implemented to be controlled on web, configuring clients to control RFID readers and building up DBMS system in a server. Especially, it grasps user's intention of storing or delivering based on toE data for the history of user's access to the system and it reports user's irregular pattern of warehouse use and serves predictive information of the control of goods in stock. As a result, the proposed system can contribute to enhance efficiency and correctness of small-scale warehouse management.