• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.214-227
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• 2003

Developing an application, it is difficult to catch an exact requirement with the conventional text-based method. It has also problems in verification and analysis at each developing stage. Therefore, if an adjustment is required with an error and change of requirement, a bad effect happen in the whole system. In this case, it also affect adversely on the developing cost and period. Meanwhile, if an analysis or verification is performed, the possibility of an error frequency reduces. Thus, not only is it easier to correct the error but also add an new requirement. This thesis embody a TCP/IP congestion control algorithm with SDL which provides automatically graphic interface, verification and analysis to each developing stage. Using SDL gave a clear representation embodiment in each developing stage and easiness of adjustment due to changing requirements or correcting errors. In addition, the stages of protocol have been certified in a simulation by verification of MSC and the results showed a possibility of developing a better TCP/IP protocol.

• Korean Institute of Interior Design Journal
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• v.25 no.5
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• pp.42-54
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• 2016

The purpose of this study is to provide a reference for stage planning by analyzing current state of major theaters' stage space and understanding feedback from directors belonged to theaters. Each room in total 18 theaters' stage facilities was measured and their usage and requirements were analyzed on the spot. In addition, each director provided their experiential knowledge about appropriate stage composition for musical performance. The findings are as follow: under stage machinery is not needed for musical. Tour teams prefer to use their own show-deck for set conversion. On the other hand, over stage flying system needs to be able to deal with dense, fast, and accurate scene change. The size and location of the motor room needs to be carefully considered. The number of set battens is directly linked up with the size of the motor room, which should be located lower than the gridiron. As stage sets get bigger and complicated, the number of works at the gridiron is also increasing. The grating floor has to have enough strength coping with machines lifting heavy sets. Most sound control for musical performance is being done at F.O.H. these days rather that in the sound control room. It should equip enough work area and related infra especially for tour teams. 1st gallery needs to have enough effective width, power infra for lighting fixture, and strong guardrail. Lastly, the whole process of parking-unloading-transporting equipments and sets from loading dock to stage and vice versa needs to be efficient, and this has to be carefully considered from early stage of planning.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.48-52
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• 2003

A mathematical dynamic model of fuel cell was formulated in order to design the control system which will meet the control object. The control objective is set to regulate the airflow in the load change by utilization of airflow and the pressure difference between anode and cathode is maintained below a limit range. Simulation result of 10kW polymer electrolyte membrane fuel cell (PEMFC) clearly demonstrates that response time need to be less. than 1 seconds for the control requirements. Besides, pressure difference was allowed in pressure range less than 0.01 atm.

• Archives of design research
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• v.13 no.1
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• pp.199-207
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• 2000

The planning of large department store is differ from designing other spaces because it holds items to sell. To make effective selling area, those items are to be showed enough to attract potential customers. In well planned space, customers would enjoy shopping convenientiy and comfortably. There are some requirements to make those kind of space. First, the design must consider customers needs. Second. the design must show items own values effectively. And third is identity of the store. At this point entrance or lobby area would possibly take major role to imprint identity and store concept. The purpose of study is to make well planned lobby area in order to lead customers traffic patterns to effective selling spaces. The method of this study is establishing hypothesis about interior and exterior aspects which effect to traffic patterns. And build condition that helps testing the hypothesis. Through the processes mentioned above, we would possibly reach the result like, First, It is important to reserve enough lobby space to prevent oversizing of selling space and advise effective traffic patterns. Second, Organize the aspects that could cause the change of customers traffic patterns and bring those customers selling point. Third, Make useful context which can attract customers passing by.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.57-65
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• 2014

Risk factors are the reason behind cost overruns and delays in long-term large-scale IT service projects. Major risks originate from the integration of complex IT system components, including software, hardware, and solutions; the competitive bidding process; the turnkey and firm-fixed price nature of contracts; and the project execution environment. We have identified several risk factors such as delay in acceptance, low quality of deliverables, delay in payment, adding and changing requirements and scope, unclear definition of roles and responsibilities of the buyer and supplier, and unclear procedures of change and quality management during the project execution phase. One needs to manage risks proactively before signing the contract. In order to weed out or lower the risk factors well in advance, we need to identify and remove risk factors contained in contract clauses and attached contract documents. We propose a checklist for assessing IT service project contracts. To validate the checklist's utility, we applied it to an IT service project in the finance industry. The results show that the checklist is effective in identifying and removing risk factors pertaining to IT service projects.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.659-664
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• 2010

This paper provides an integrated framework for biometric data and private information protection in TeleHealth. Biometric technology is indispensable in providing identification and convenience in the TeleHealth environment. Once biometric information is exposed to mallicious attacker, he will suffer great loss from the illegferuse of his biometric data by someone else because of difficulty of change not like ID and password. We have to buil by someone esystem data bon the integrated framework for biometric data and private information protection in TeleHealth. First, we consider the structure of the biometric system and the security requirements of y someone esystem data bon the biometrics. And then, we define the TeleHealth system model and provide the vulnerabilities and countermeasures of the biometric-data by someone eintegrated model.byhe TeleHealth sse bec requires two-phata authentication for countermeasure. Finally, we made some functionferrequirements for main componenets of biometric-data bintegrated TeleHealth system framework to protect biometric data.

• Journal of Practical Engineering Education
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• v.8 no.1
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• pp.9-14
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• 2016

Depending on the college graduation project and graduation thesis regulations for the certification and graduation requirements, the quadcopter acting as a Li-Po battery that charges by solar energy are proposed a design method and improvements in theory. Quadcopter posture is balanced and confirmed by the position sensor, through a PID (Proportional Integral Differential) control. Battery switching circuit is composed of two Li-Po battery. Driving the quadcopter as one battery, and does not use other battery is charged by solar energy. A battery switching circuit is fabricated in a manner that uses two types of relays. Even if completely not charged to the battery is being driven a certain switch by the battery charging voltage from time to time, it proposes a method for increasing the endurance time and range.

• Korean Journal of Materials Research
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• v.21 no.11
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• pp.628-633
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• 2011

Studies on lead-free piezoelectrics have been attractive as means of meeting environmental requirements. We synthesized lead-free piezoelectric $(Bi_{1/2}Na_{1/2})TiO_3-Ba(Cu_{1/3}Nb_{2/3})O_3$ (BNT-BCN) ceramics, and their dielectric, piezoelectric, and strain behavior were characterized. As BCN with a tetragonal phase was incorporated into the rhombohedral BNT lattice, the lattice constant increased. A small amount of BCN increased the density and dielectric constant forming the complete solid solution with BNT. However, BCN above 10 mol% was precipitated into a separate phase, and which was detected with XRD. In addition, EDX measurement revealed that Cu in BCN was not distributed homogeneously but was accumulated in a certain area. A lower density with a large amount of BCN was attributed to the nonsinterable property of BCN with large tetragonaliy. The dielectric constant vs the temperature change and the strain vs the electric field indicated that the ferroelectric property of BNT was diminished and paraelectric behavior was enhanced with the BCN addition. BNT-7.5BCN showed a 0.11% unimorph strain with a 9.0 kV/mm electric field with little hysteresis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.1103-1108
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• 2012

A main steam pipe system is a branch pipe that connects a boiler with a turbine. Water hammering analysis is very important for limiting the damage caused to pipe systems by operation conditions. Water hammering created by an unsteady flow in pipeline systems can cause excessive change in pressure, vibration, and noise. The main steam pipe structure should be designed to safely maintain the pressure pulsation and several vibrations under operation environments. This study evaluated the structural integrity of a main steam pipe during suspended and normal operation by using the ASME fatigue life methodology and finite element analysis. In the analysis, water hammering was used for transient analysis. The calculated alternating stress and fatigue stress were compared with the applicable limits of ASME fatigue life. All the evaluation results satisfied the requirements of the ASME fatigue life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4183-4191
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• 2011

Considering the characteristics of a data stream whose data elements are continuously generated and may change over time, there have been many techniques to differentiate the importance of data elements in a data stream by their generation time. The conventional techniques are efficient to get an analysis result focusing on the recent information in a data stream, but they have a limitation to differentiate the importance of information in various ways more flexible. An information differentiation technique based on the term of a fuzzy set can be an alternative way to compensate the limitation. A term of a fuzzy set has been widely used in various data mining fields, which can overcome the sharp boundary problem and give an analysis result reflecting the requirements in real world applications more. In this paper, a fuzzy window mechanism is proposed, which is adapting a term of a fuzzy set and is efficiently used to differentiate the importance of information in mining data streams. Basic concepts including fuzzy calendars are described first, and subsequently details on data stream mining of weighted patterns using a fuzzy window technique are described.