• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.255-260
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• 2003

In recent, as a typical example of RFID, the contactless IC card is widely used in traffic, access control system and so forth. And its use becomes a general tendency more and more because of the development of RF technology and improvement of requirement for user convenience. This paper describes the hardware module to process embedded contactless protocol for implementation contactless IC card. And the hardware module consists of analog circuits and specific digital logic circuits. This paper also describes more effective design method of contactless IC card, which method separates into analog circuit parts, digital logic circuit part, and software parts according to the role of the design parts.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.567-575
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• 2008

Transient security assessment(TSA) is becoming an essential requirement not only for security monitoring but also for stabilizing control of power systems under new electricity environments. It has already been pointed out that fast transient stability study is an important part for monitoring and controlling system security. In this paper, we discuss an energy function method for stabilizing control of transiently unstable systems by introducing generator tripping system to enhance the transient stability of power systems. The stabilization with less tripped power can be obtained by tripping the generators faster than out-of-synchronism relay. Fast transient stability assessment based on the state estimation and direct transient energy function method is an important part of the stabilizing scheme. It is possible to stabilize the transiently unstable system by tripping less generators before the action of out-of-synchronism relay, especially when a group of generator are going to be out-of-synchronism. Moreover, the amount of generator output needed for tripping can be decided by Transient Energy Function(TEF) method. The main contribution of this paper is on the stabilizing scheme which can be running in the Wide Area Control System.

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.165-172
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• 2010

Sensor network can be applied in many areas in our life, and security is very important in applying sensor network. For secure sensor communication, pairwise key establishment between sensor nodes is essential. In this paper, we cluster the network field in hexagonal shapes and preassign three different kinds of key information for each sensor according to its expected location. We adopt overlapped key string pool concept for our clustered network architecture and every node uses the part of sub-strings for setting up pairwise keys with all neighboring nodes in its own cluster and from different clusters according to respective position with small amount of information. Our proposal decreases the memory requirement and increases security level efficiently.

• Tribology and Lubricants
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• v.40 no.1
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• pp.24-27
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• 2024

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.287-294
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• 2003

The purpose of this study was to develop a web-based internet program for nutritional assessment and diet management of patient having hyperlipidemia. Hyperlipidermia were classified by hypercholesterolemia and hypertriglyceridemia. The program consisted of four parts according to their functions and contents. The first part explained the metabolism of lipids and defined the hyperchotesterolemia and hypertriglyceridemia. The second part is to assess the general health status such as body weight, obesity index, basal metabolic rate and total energy requirement by the input of age, sex, height, weight and degree of activity. This part also provides the Patient with menus lists and 1 day menu suitable to his weight, activity and the status of hyperlipidemia and offers the information for food selection, snacks, convenience foods, dine-out, behavioral modification, cooking methods, food exchange lists, and information on energy and nutrients of foods and drinks, and top 20 foods classified by nutrients. The third part is designed to investigate diet history of patient, that is, to find out his inappropriate dietary habit and give him some suggestions for appropriate dietary behavior. This part also offers on-line counseling and frequently asked Questions. The fourth part is evaluating their energy and nutrients intake by comparing with recommended dietary allowance for Koreans or standardized data for patient with hyperlipidemia. In this part, it is also analyzing energy and nutrients of food consumed by food group and meals, and evaluating the status of nutrient intake. These results are finally displayed as tabular forms and graphical forms on the computer screen.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.193-199
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• 2014

As the requirement on the quality of the system has increased, the reliability is very important part in terms of enhance stability and to provide high quality services to customers. Many statistical models have been developed in the past years for the estimation of software reliability. We consider the functions for NHPP software reliability model and time series model in software failure data. We estimate parameters for the proposed models from three data sets. The values of SSE and MSE is presented from three data sets. We compare the predicted number of faults with the actual three data sets using the NHPP software reliability model and time series model.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.311-316
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• 2003

To deploy multicast protocols, fairness to current Internet traffic, particularly TCP, is an important requirement. PGMCC is one of the most promising multicast congestion control proposals but it suffers from degradation of fairness by fixed timeout and uncertain acker selection. In this paper, we suggest addition of an adaptive timeout mechanism and NAK suppression in router using throughput comparison to improve fairness. Our simulation show improved fairness.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.255-260
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• 2011

The train control system is a facility to ensure safe train operation, and its safety is the most important factor for system introduction. Therefore, in order to improve practical usability in the business, safety analysis and evaluation of train control system and train control related core technologies are needed. Korea Railroad Research Institute has carried out standard development of radio-based train control system as a government research and development project. In this paper, we present a system specification of ATP, a core part of train control system, for standard system of Korean radio-based train control system(KRTCS). The paper present a operation environment and primary ATP functions, and functional requirement specifications.

• International Journal of High-Rise Buildings
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• v.4 no.4
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• pp.261-270
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• 2015

Hong Kong is a renowned small city with densely placed skyscrapers. It is no surprise that heavy duty or even mega foundations are built over the years to support these structures. To cope with the fast construction pace, several heavy deep foundation types have been widely adopted with some prescribed design rules. This Paper has selected two commonly adopted but distinctive foundation types, namely large diameter bored piles and percussive steel H-piles to illustrate the special design and construction considerations related to these pile types in related to local context. The supervision requirement in related to foundation works for which again may be unique in Hong Kong will also be highlighted. A case history is also discussed in the later part of the Paper to illustrate the application of one of these foundations and to highlight the importance of considering foundation design and basement excavation method in a holistic manner.

• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.43-53
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• 1990

Mechanical components and structures are a major part of complex systems and the conseguences of their failure can be extremely costly. The ultimate goal of design engineers is to optimize these mechanical and structural design from the point of view of cost, reliability, weight, volume, maintainability and safety. An essential requirement of design optimization is to develop mathematical models for reliability at design stage. This paper is to minimize the cost of resources subject to the constraint that the reliability of the system must meet a specified level. The lagrange multiplier method is used to optimize the lognormal stress-lognormal strength problem. This optimization problem can be reduced to a search problem in one variable. A numerical example is presented to illustrate the optimization problem.