• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1223-1231
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• 2010

The design is presented for a SATCOM antenna capable of simultaneous multi-band (X/Ku/Ka-Band) communications without replacement of feed horns or change of other parts in the application as a ground satellite terminal for large data transfer. The antenna is the offset configuration and consists of a dual-band(X/Ka-band) feed horn, a single-band(Ku-band) feed horn, a frequency selective surface(FSS) sub-reflector and a parabolic main-reflector. The antenna has a main reflector defining a prime focus and a frequency selective surface sub-reflector defining an image focus. A dual-band feed and a single-band feed are provided at each of the prime focus and image focus. The antenna is designed using 3D EM simulator and the gains measured in X/Ku/Ka-band of the complete antenna assembly is more than 31.6dBi, 36.8dBi, 40.8dBi, and the cross polarization is 21.7dB, 26.6dB, 25.2dB, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.767-774
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• 2010

In a passive-type PEMFC stack, axial fans operate to supply both oxidant and coolant to cathode side of the stack. It is possible to make a simple system because the passive-type PEMFC stack does not require additional cooling equipment. However, the performance of a cooling system in which water is used as a coolant is better than that of the air-cooling system. To ensure system reliability, it is essential to make cooling system effective by adopting an optimal stack design. In this study, a numerical investigation has been carried out to identify an optimum cooling strategy. Various channel configurations were applied to the test section. The passive-type PEMFC was tested by varying airflow rate distribution at the cathode side and external heat transfer coefficient of the stack. The best cooling performance was achieved when a channel with thick ribs was used, and the overheating at the center of the stack was reduced when a case in which airflow was concentrated at the middle of the stack was used.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.961-964
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• 2013

Arduino is for design based on open source prototyping platform, artist, designer, hobby activists, etc, i has been designed for all those who are interested in the environment construct. Arduino adventage you can easily create applications hardware, without deep knowledge about the hardware. Configuration of arduino using AVR microcontroller ATmage 168, software to action arduino using arduino program, MATLAB, Processing. Arduino is open source base, you can hardware production directly and using shield additionally, the arduino can be combined. Android is open source. Continue to expand through a combination of hardware, Arduino. It name is shield. Be given to the Arduino Uno board to the main board, the shield extends to the various aspects and help can be equipped with more features. The shield on top of the shield can be combined as a kind of shield and Ethernet shield, motor shield, the shield RFID hardware beyond a simple extension can be configured. In this paper, sortware was used for arduino program, hardware was used for arduino Uno board, the additional shield using RFID shield. Configure the hardware to be compatible with this tag combined the 13.56MHz tag SM130.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.363-368
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• 2008

Mobile devices become more complex and harder to manage due to the advance of technologies. In this paper, we designed and implemented the DM Agent based on OMA(Open Mobile Alliance) DM(Device Management) which is a standard for mobile device management. The proposed DM Agent basically can manage parameter configuration through the commands ADD, DELETE, REPLACE and GET currently. Each module of the agent was designed and implemented separately for additional functions such as error reporting and software management. So the additional functions can be added by modifying Adaptor part which processes the management commands instead of modifying other modules which analyze or generate management commands. The DM Agent proposed in this paper is implemented based on WIPI(Wireless Internet Platform for Interoperability), therefore portability of the agent can be improved. In addition, this research can give a development example for dissenminating OMA DM as well as verify functional compatibility of WIPI platform. SK WIPI SDK and a Funambol DM test server are used to test operations of the implemented DM Agent.

• The KIPS Transactions:PartC
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• v.14C no.1 s.111
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• pp.27-38
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• 2007

IPv6 has appeared for solving the address exhaustion of IPv4 and for guaranteeing the problems of security and QoS. It occurs the unexpected new attacks of IPv6 as well as the existing attacks of IPv4 because of the increasing address space to 128bits and the address hierarchies for efficient network management and additions of the new messages between nodes and routers like neighbor discovery and auto address configuration for the various comfortable services. For the successful transition from IPv4 to IPv6, we should get the secure compatibility between IPv4 hosts or routers working based on secure and systematic policy and IPv6. Network manager should design security technologies for efficient management in IPv4/IPv6 co-existence network and IPv6 network and security management framework designation. In this paper, we inspected the characteristics of IPv4 and IPv6, study on security requirement for efficient security management of various attacks, protocol, service in IPv4/IPv6 co-existence and IPv6 network, and finally suggest integrated solution about security vulnerability of IPv6 network in considering of analysis of IPv6 system, host and application, IPv6 characteristics, modified CGA(MCGA).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.167-175
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• 2019

Recently, health examination centers have been changing from auxiliary medical facilities to key and independent medical facilities. However, it is not easy to improve medical facilities, including health examination centers, due to the variable characteristics of the relationship between humans and space. Therefore, this study was done to develop a pedestrian-based discrete event simulation analysis program to examine the problems and develop methods for improvement. The program was developed to analyze five evaluation indices and the density of examinees. The problems were derived by analyzing the required time, capacity, and queue size for each examination through simulations. We reduced the examination time and moving distance, increased the capacity, and distributed the queues by adjusting the medical services and relocating the examination rooms. The results were then quantitatively verified by simulations.

• Journal of Distribution Science
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• v.13 no.7
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• pp.41-51
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• 2015

Purpose - This study analyzes loading efficiency by loading pattern for package standardization and reduction of logistics costs, along with the creation of revenue for the revenue review panel (RRP) of Membership Wholesale Clubs (MWC). The study aims to identify standard dimensions that can help improve the compatibility of the pallets related to display patterns preferred by the MWC and thereby explore ways to enhance logistics efficiency between manufacturers and retailers through standardization. Research design, data, and methodology - The study investigates and analyzes the current status based on actual case examples, i.e., manufacturer A and Korea's MWC (A company, B company, and C company), and thus devises improvement measures. To achieve this, the case of manufacturer A delivering to MWC was examined, and the actual pallet display patterns for each MWC were investigated by visiting each distribution site. In this study, TOPS (Total Optimization Packaging Software, USA) was used as the tool for pallet loading efficiency simulations the maximum allowable dimension was set to 0.0mm to prevent the pallet from falling outside the parameters, and the loading efficiency was analyzed with the pallet area. In other words, the study focused on dimensions (length x width x height) according to the research purpose and thereby deduced results. Results - The analysis of pallet loading patterns showed that the most preferred loading patterns for loading efficiency according to product specification, such as pinwheel, brick, and block patterns, were used in the case of the general distribution products, but the products were configured with block patterns in most cases when delivered to MWCs. The loading efficiency by loading pattern was analyzed with respect to 104 nationally listed standard dimensions. Meanwhile, No.51 (330 × 220mm) of KS T 1002 (1,100 × 1,100mm) was found to be the dimension that could bring about an improved loading efficiency, over 90.0% simultaneously in both the T-11 and T-12 pallet systems in a loading pattern configuration with the block pattern only, and the loading efficiency simulation results also confirmed this as the standard dimension that can be commonly applied to both the T-11 pallet (90.0%) and the T-12 pallet (90.7%) systems. Conclusions - The loading efficiency simulation results by loading pattern were analyzed: For the T-11 pallet system, 17 standard dimension sizes displayed the loading efficiency of 90.0% or more as block patterns, and the loading capacity was an average of 99.0%. For the T-12 pallet system, 35 standard dimension sizes displayed the loading efficiency of more than 90% as block patterns (the average loading efficiency of 98.6%). Accordingly, this study proposes that the standard dimensions of 17 sizes with the average loading efficiency of 99.0% should be applied in the use of the T-11 pallet system, and those of 35 sizes with the average loading efficiency of 98.6% should be reviewed and applied in the use of the T-12 pallet system.

• Journal of Distribution Science
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• v.11 no.10
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• pp.81-92
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• 2013

Purpose - This study empirically analyzes the effect of improvements in the quality of service management performance of college education on traders' conscious change of business management innovation and diverse sales expertise for a year. The use of traders' conscious changes and sales expertise as variables for the verification of the effects of parameters related to the active trader's traditional education market is a desirable direction. The method of research reflects the quality of education service, management result, traders' conscious changes, and sales expertise to understand the precise essence and definition of teaching quality at merchant colleges through theoretical consideration. Moreover, its impact on traders' conscious changes and sales expertise in empirical analysis acts as an intermediary. Research design, data, methodology - The hypothesis of this study leverages the SPSS statistical program. To gather actual proof, sample survey for theoretical research examined 262 valid papers of the 300 papers written by 10 merchants who graduated from merchant's university. First, using the SERVQUAL model, Parasuraman et al. (1996) indicated that for quality of education service, the configuration of factors is the same as the sympathetic performance, that is, responsiveness and empathy, and traders are aware of these elements. However, our preliminary investigation revealed that traders' university education has been excluded as a component of quality of service in the earlier studies. Moreover, we found that certainty of knowledge, reliability, and sympathy are influenced by challenges and by the changing intentions of merchant consciousness. In addition, our study confirms that improvements in convincing abilities and sales technique have a positive impact. Second, merchants' and traders' expertise are proven to affect business performance. In other words, university education of traders and merchants affects the consciousness of consumers, and changes patterns of sales. Third, the quality of service management education and change in the consciousness has a considerable impact on the trader, thereby maximizing business performance and acting as an intermediary for verification. Fourth, the quality of service management education affects the trader's sales expertise to maximize business performance. Results - To summarize, the quality of college educational services relates to the improvement of business performance and the role of the resulting virtuous cycle. Consequently, we can look for suggestions in the traditional markets, where the Government pays attention to the exterior environmental factors as well as to the changing business environment. However, the most important aspect is the merchant awareness. That is, a merchant should understand the distribution environment. Several competitor and trend analyses should be conducted to meet customers' expectations positively and proactively cope with any challenges related to changes. Further, expertise in sales and marketing skills need to be acquired to improve customer convincing abilities and develop a customer-oriented mindset. Conclusions - According to the changes in consumption trends of business enterprises, new management techniques are required to survive competition by improving traditional markets, which will necessitate more competitive education programs in merchant universities.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.165-169
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• 2004

The BLAST server for the mollusk was constructed on the basis of the Intel Server Platform SC-5250 dual Xeon 2.8 GHz cpu and Linux operating system. After establishing the operating system, we installed NCBI (National Center for Biotechnology Information) WebBLAST package after web server configuration for cgi (common gate interface) (http://chimp.kribb.re.kr/mollusks). To build up the stand alone blast, we conducted as follows: First, we downloaded the genome information (mitochondria genome information), DNA sequences, amino acid sequences related with mollusk available at NCBI. Second, it was translated into the multifasta format that was stored as database by using the formatdb program provided by NCBI. Finally, the cgi was used for the Stand Alone Blast server. In addition, we have added the vector, Escherichia coli, and repeat sequences into the server to confirm a potential contamination. Finally, primer3 program is also installed for the users to design the primer. The stand alone BLAST gave us several advantages: (1) we can get only the data that agree with the nucleotide sequence directly related with the mollusks when we are searching BLAST; (2) it will be very convenient to confirm contamination when we made the cDNA or genomic library from mollusks; (3) Compared to the current NSBI, we can quickly get the BLAST results on the mollusks sequence information.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.2
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• pp.114-120
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• 2011

The characteristics of a helical turbine to be used for tidal stream energy conversion have been numerically studied with varying a few design parameters. The helical turbines were proposed aiming at mitgating the well known poor cut-in characteristics and the structural vibration caused by the fluctuating torque, and the basic concept is introducing some twisting angle of the vertical blade along the rotation axis of the turbine. Among many potential controling parameters, we focused, in this paper, on the twisting angle and the height to diameter ratio of the turbine, and, based on the numerical experiment, We tried to propose a configuration of such turbine for which better performance can be expected. The three-dimensional unsteady RANS equations were solved by using the commercial CFD software, FLUENT with k-${\omega}$ SST turbulence model, and the grid was generated by GAMBIT. It is shown that there are a range of the twisting angle producing better efficiency with less vibration and the minimum height to diameter ratio above which the efficiency does not improve considerably.