• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권1호
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• pp.16-29
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• 1991

미세혈관봉합술에서의 가장 큰 문제점은 봉합부에서의 내피손상과 혈전형성이라고 볼 수 있다. 이 연구의 목적은 봉합시 일어날 수 있는 내피손상부에서의 치유과정을 관찰코져 각각 다른 문합술인 혈관함입문합술과 혈관단단문합술을 백서 대퇴부동맥에 적용하여 개존율및 전자현미경적 관찰을 통하여 비교하였고 아울러 임상에의 적용 가능성을 검토코져 하였다. 저자는 미세현미경시야에서 혈관함입문합술 20례와 단단문합술 20례를 시행한후 1일, 3일, 1주, 2주, 3주에 각각 4마리씩 희생후 문합혈관부를 육안관찰후 주사전자현미경으로 조직변화를 관찰하여 다음의 결과를 얻었다. 1. 혈관 함입문합술 시술시 문합후 개존율은 90%였고 혈관 단단문합술은 85%였다. 2. 혈관 함입문합시 술후 3일째는 문합부에서의 혈소판 응집물이 기질화되었으며 함입으로 좁아져 있던 혈관내경이 약 1주째 혈관 합입부의 중막 위축현상으로 다소 넓어졌다. 3. 혈관 내피재생과정을 혈관 함입문합술에서는 7일에서 14일경에, 혈관 단단문합술에서는 14일에서 21일째 완성되었다.

• 한국공작기계학회논문집
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• 제11권6호
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• pp.1-9
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• 2002

This study describes the geometric characteristics and the 5-axis machining method in order to make end mill cutter coming with insert tips. End mill geometry is consisted of flute part and insert tip part. Flute part modeled by using ruled surfaces with constant helix angle, and insert tip part modeled by rectangular planes containing tapped hole of specified direction in its center. In this study, the modeled insert tip part considered both of a radial rake angle and a axial rake angle, because they were important cutting conditions. In order to machining the virtual end mill defined from geometric characteristics, we programmed a special software to machining the end mill considered in this study. This software can generate NC-codes about following processes, end milling or ball end milling of flute part end milling of rectangular plane, centering of hole, drilling of hole, and tapping of hole. Ant sampled end mills were modeled and machined on 5-axis CNC machining center with two index tables. Since machined end mills were very agreeable to designed end mills, we saw that the method proposed in this study can be very useful for manufacturing of end mill body with insert tip.

• 산업기술연구
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• 제29권B호
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• pp.33-39
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• 2009

The need for end-to-end security has been increased with the widespread use of mobile devices in wireless internet access applications such as mobile commerce. The WAP1.x has an end-to-end security problem that the message transmitted between the mobile device and the Web server is decrypted inside the gateway within a short time. To overcome this problem, several protocols including WAP2.0 has been proposed. These protocols require that the heavy modules such as TLS or data compression modules should be installed on the mobile device with limited resources. This paper proposes a new WTLSW(WTLS-TLS at Web server) protocol and a new WAP2.0 proxy model in order to ensure end-to-end security between the mobile device and the Web server and to be appropriate for mobile devices with limited resources.

• 융합보안논문지
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• 제7권2호
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• pp.65-71
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• 2007

전자금융거래를 위해 이용자 PC에서 작동되고 있는 보안프로그램은 금융정보를 탈취하려는 악의적인 자로부터 이용자들을 보호하기 위해 보안기능을 가지고 있는 프로그램이다. 하지만 금융범죄를 자행하기 위한 악의적인 자는 해킹을 이용하여 사이버 상에서 타인의 자산을 훔치는 것과 같은 범죄를 저지르고 있다. 따라서 본 논문에서는 백신 프로그램이나 개인 방화벽과 같은 보안프로그램의 보안기능을 우회하는 해킹 툴에 의해 데이터 절취가 가능한 취약점에 대해 분석하고 이에 대한 대응방안으로 현재 작동되고 있는 보안프로그램 중 PKI 응용프로그램과 키보드 보안프로그램의 연동으로 제공될 수 있는 종단간 암호화(End-to-End Encryption) 방안에 대해서 살펴본다.

• Journal of the Korean Wood Science and Technology
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• 제18권2호
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• pp.79-85
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• 1990

Traditional complex joints have used to a wide variety of wooden furniture construction. Dowel joint is the most popular joint s. However design of this joint to meet specified service condition has been hampered by a lack of proven design formulas which can be use to predict their strength. The object of this study is to investigate the withdrawal strength and effect of dowel diameters in wood and wood based materials. The obtained results were as follows; 1. The relationship between withdrawal strength and dowel diameter is found to be linear. 2. Withdrawal strength of medium density fiberboard and Sepetir in end-to-side joints is superior to Antiaris, particleboard and plywood. 3. In end-to-end joints, withdrawal strength of medium density fiberboard is the most superior joint. but Sepetir. Antiaris and plywood have similarly strength and particleboard is inferiority. 4. Withdrawal strength in end-to-end joints of Antiaris and plywood is higher than in end-ta-side joints. But in end-to-end joints of Sepetir. medium density fiberboard and particleboard is similarity in end-to-side joints.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.465-467
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• 2010

This paper proposes MIMO two-way cooperative relay scheme to optimize the end to end capacity in wireless multi-hop mesh network. The basic idea is to perform data transmission via multi-hop relay nodes, in equidistant topology, this method is quite efficient. However, on one hand this topology is very rare in practical situation, on the other hand, in real practical situation where the topology is most likely non equidistant, the end to end capacity significantly degrades due to bottleneck link caused by uneven SNR. Moreover, the end to end capacity degrades at high SNR due to overreach interference from far nodes existing in multi-hop relay networks. In this paper, MIMO two-way cooperative relay in the region of non equidistant nodes is found efficient to improve the end to end capacity. The proposed scheme is validated using numerical simulation.

• 한국항행학회논문지
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• 제15권2호
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• pp.248-255
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• 2011

분산 보상 구조가 광 위상 공액기 (OPC; optical phase conjugator)를 갖는 960 Gbps의 파장 분할 다중 (WDM; wavelength division multiplexed) 시스템에 미치는 영향을 컴퓨터 시뮬레이션을 통해 살펴보았다. 본 연구에서 고려한 분산 보상 구조는 전통적인 one-end 구조와 bi-end 구조이다. one-end 구조와 bi-end 구조는 하나의 단일 모드 광섬유 (SMF; single mode fiber) 중계 간격마다 축적된 분산량을 줄여주기 위하여 각각 하나의 분산 보상 광섬유 (DCF; dispersion compensating fiber)와 두 개의 DCF를 사용하여 만들어진다. 전체 잉여 분산 (NRD; net residual dispersion)이 최적화되면 중계 거리 당 잉여 분산 (RDPS; residual dispersion per span)이 400 ps/nm인 WDM 시스템에서 bi-end 구조와 one-end 구조는 거의 동일한 성능을 나타내는 것을 확인하였다.

• 한국의류학회지
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• 제29권11호
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• pp.1381-1388
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• 2005

The purpose of this study was to identify features of masstiege high-end products by comparing to original old high-end products. For this purpose, the differences in values between each consumer groups divided by preferred products types (high-end products, original old high-end products) were examined. This study was executed by consumer survey and 279 female data were used in analysis. The results are as follows. First, the value factors pursued on high-end products were constructed by factor analysis and the factors consisted of 4 elements; conspicuous, aesthetic, durable, conformity. Next, the differences in value elements between masstiege high-end products and original old high-end products were identified by t-test. The consumers preferring original old high-end products pursued conspicuous features significantly more and the consumers preferring masstiege high-end products considered aspects of aesthetic and conformity elements as more important. And according to kinds of preferring high-end product, demographic characteristics were different. The consumers who were of high age, high education and high income and married consumers preferred original old high-end products, whereas the consumers who were of low age, low education and low income and unmarried consumers preferred masstiege high-end products. Finally, marketing strategies for masstiege brand were suggested on the base of the results.

• 한국CDE학회논문집
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• 제17권1호
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• pp.1-6
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• 2012

The End Coupling is main component of the aluminum hot roll process. The End Coupling is used for transmission of rotational power with heavy-duty load. Fracture of the End Coupling cause serious economic losses because an End Coupling is a very expensive component and it takes a long time to repair it. Therefore, preventing the destruction of the End Coupling is essential for ensuring a long mechanical life cycle. In this paper, the parametric study on the End Coupling was performed in order to minimize maximum stress under operation loads. To verify the interference of spindle assembly with modified End Coupling, kinematics simulation was performed by applying the various combination type and dynamic boundary condition of the spindle assembly. The interference of optimized model was not occurred during combination process and driving process. As a result of an optimum design for life extension on End Coupling, the maximum stress of modified End Coupling was lower than that of the initial model by 26%.

• Journal of Communications and Networks
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• 제18권4호
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• pp.580-588
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• 2016

Energy efficiency is the main objective in the design of a wireless sensor network (WSN). In many applications, sensing data must be transmitted from sources to a sink in a timely manner. This paper describes an investigation of the trade-off between two objectives in WSN design: minimizing energy consumption and minimizing end-to-end delay. We first propose a new distributed clustering approach to determining the best clusterhead for each cluster by considering both energy consumption and end-to-end delay requirements. Next, we propose a new energy-cost function and a new end-to-end delay function for use in an inter-cluster routing algorithm. We present a multi-hop routing algorithm for use in disseminating sensing data from clusterheads to a sink at the minimum energy cost subject to an end-to-end delay constraint. The results of a simulation are consistent with our theoretical analysis results and show that our proposed performs much better than similar protocols in terms of energy consumption and end-to-end delay.