• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1075-1076
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• 2011

This paper compares performance characteristics and mechanical design specifications of outer rotor radial flux type and double-sided axial flux type permanent magnet generator for 1.5-kW class small scale wind power applications to suggest most suitable type. In order to analyze electromagnetic performances of two different type generators, this paper performs generating performance and efficiency characteristic analysis from electrical parameters obtained by using nonlinear finite element analysis using commercial software, electromagnetic losses characteristics equations and d-q characteristics equation. Considering the derived electromagnetic performance, mechanical design specifications and manufacturing cost, the best suitable model for 1.5-kW class wind power system is determined, and its experiment was performed to validate the suggested analysis method.

• 한국전자통신학회논문지
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• 제9권2호
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• pp.173-180
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• 2014

본 논문은 토양에서 복사되는 마이크로파 대역의 미약한 열잡음 전력을 수신하여 토양 수분 함유량의 변화를 실시간으로 원격모니터링이 가능한 L-Band 마이크로파 라디오미터를 설계하는 내용에 관하여 기술한다. 토양 수분 함유량 0%~50%의 측정범위와 최대 오차 2%의 목표 성능을 달성하기 위해 토양 수분함유량에 따른 토양의 복사특성을 연구 및 목표 사양을 도출하였으며, 이를 바탕으로 도출된 사양을 만족시키는 마이크로파 라디오미터의 수신기를 설계 및 제작하였다. 제작된 수신기는 주파수 1390MHz, 대역폭 40MHz으로 50dB의 시스템 이득과 1.54dB의 NF를 가지며, 최대 0.313K, 평균 0.19K의 수신감도를 갖는다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.797-799
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• 2006

The Electro-optical camera subsystem as a payload of a satellite system consists of OM (optical module) and CEU(camera electronics unit), and most performances of the camera subsystem depend a lot on the CEU in which TDI CCDs(Time Delayed Integration Charge Coupled Device) take the main role of imaging by converting the light intensity into measurable voltage signal. Therefore it is required to specify and design the CEU very carefully at the early stage of development with overall specifications, design considerations, calibration definition, test methods for key performance parameters. This paper describes the overview of CEU development. It lists key requirement characteristics of CEU hardware and design considerations. It also describes what kinds of calibration are required for the CEU and defines the test and evaluation conditions in verifying requirement specifications of the CEU, which are used during acceptance test, considering the fact that CEU performance results change a lot depending on test and evaluation conditions such as operational line rate, TDI level, and light intensity level, so on.

• Journal of Positioning, Navigation, and Timing
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• 제5권3호
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• pp.157-163
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• 2016

Clocks for time synchronization using radio signals such as global navigation satellite system (GNSS) may lose reference signals by intentional or unintentional jamming. This is called as holdover. When holdover occurs, a clock goes into free run in which synchronization performance is degraded considerably. In order to maintain the required precise time synchronization during holdover, accurate estimation on main parameters such as frequency offset and frequency drift is needed. It is necessary to implement an optimum filter through various simulation tests by creating clock noise in accordance with given specifications in order to estimate the main parameters accurately. In this paper, a method that creates clock noise in accordance with given specifications is described.

• 정보저장시스템학회논문집
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• 제2권3호
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• pp.163-168
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• 2006

Small form factor optical pickup (SFFOP) corresponding to BD specifications is strongly proposed for the next-generation portable storage device. In order to generate SFFOP, small sized optical pickup has been fabricated. We have developed a small sited optical pickup that is called the integrated optical pickup (IOP). The fabrication method of this system is mainly dependant on the use of the wafer based micro fabrication technology, which has been used in MEMS process such as photolithography, reactive ion etching, wafer bonding, and packaging process. This approach has the merits for mass production and high assembling accuracy. In this study, to generate the small sized optical pickup for high recording capacity, IOP corresponding to BD specifications has been designed and developed, including three main parts, 1) design, fabrication and evaluation of objective lens unit, 2) design and fabrication of IOP and 3) evaluation process of FES and TES.

• 한국통신학회논문지
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• 제22권9호
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• pp.2062-2073
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• 1997

동기식 전송망과 장치를 설계할 때 고려해야 할 중요사항은 최대 노드수와 노드의 클럭특성이다. 이를 위해서는 클럭상태가 정상상태일 때 뿐 아니라 단기위상순서변위, 그리고 장기위상변위 등에 관한 클럭특성 연구가 필요하다. 따라서 본 논문에서는 국내 동기클럭 분배망의 구성을 바탕으로 최근 확정된 ITU-T 및 ANSI의 클럭규격을 적용하여 동기식 선형망에서 정상상태와 위상변위상태일 때의 망구성에 따른 MTIE 및 TDEV 특성을 살펴보았고, ITU-T와 ANSI규격을 동시에 만족하는 최대 노드수를 제시하였다. 또한 본 논문에서 얻은 결과를 AT&T의 것과 비교 분석하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권1호
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• pp.62-80
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• 2013

This paper has been focused on developing a new hybrid mount for shipboard equipment used in naval surface ships and submarines. While the hybrid mount studied in our previous research was 100 kg-class series-type mount, the new hybrid mount has been designed as an inertia-type mount capable of supporting a static of 500 kg. The proposed mount consists of a commercial rubber resilient mount, a piezostack actuator and an inertial mass. The piezostack actuator connected with the inertial mass generates actively the control force. The performances of the proposed mount with a newly designed specific controller have been evaluated in accordance with US military specifications and compared with the passive mount. An isolation system consisting of four proposed mounts and auxiliary devices has been also tested. Through a series of experimental tests, it has been confirmed that the proposed mount provides better performance than the US Navy's standard passive mounts.

• 한국정보처리학회논문지
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• 제6권12호
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• pp.3500-3513
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• 1999

객체지향 기법과 정형 기법은 미래의 소프트웨어 공학 분야에 지대한 영향을 미칠 잠재력을 가진 두 갈래의 큰 영역으로 인식되고 있다. 따라서 이 두 영역의 접목 "객체지향 기술을 이용한 시스템 명세의 정형적 접근"은 빠른 속도로 성장하고 있으며 많은 연구결과를 산출하고 있다. LOTOS는 객체 기반 접근에 매우 적절하나, 완전한 객체지향 접근 방법을 제공하기 위하여 일반화(상속과 다형성)를 모델링할 수 있어야 한다. 이러한 주제를 연구해온 대부분의 연구자들은 LOTOS을 확장을 제안하였다. 본 논문은 ISO 8807 LOTOS로의 변환에 관심을 두며, 이러한 연구 동향의 일환으로 UML 정적구조 다이아그램으로부터 LOTOS 명세를 생성하는 방법을 제안한다.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.596-601
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• 2013

In the current pavement construction practice, the state agencies traditionally determine the quality of the as-constructed pavement mix based on individual mixture material parameters (e.g., air voids, cement or asphalt content, aggregate gradation, etc.) and consider these parameters as key variables to influence payment schedule to the contractors and the present and future quality of the as-constructed mixture. A set of empirically pre-determined pay adjustment schedule for each parameter that was differently developed and being used by the individual agencies is then applied to a given project, in order to judge whether each parameter conforms to the designated specifications and consequently the contractor may either be rewarded or penalized in accordance with the payment schedule. With an improved quality assurance system, the Performance Related Specification, the individual parameters are not utilized as a direct judgment factor; rather, they become independent variables within a performance prediction function which is directly used to predict the performance. The quantified performance based on the prediction model is then applied to evaluate the pavement quality. This paper presents the brief history of the quality assurance in asphalt pavement construction including the Performance Related Specifications, statistical performance models in terms of fatigue and rutting distresses, as an example of the performance prediction models, and envisions the possibilities as to how this Performance Related Specification could be utilized in other infrastructures construction quality assurance.

• 한국의상디자인학회지
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• 제25권3호
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• pp.17-29
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• 2023

This study collected and analyzed reference information on the size labeling method and size of clothing products in 13 online shopping malls for plus size women in their 20s and 30s, and compared the size specification information focusing on jeans. First, in the results of examining the method of clothing size designation, clothing sizes indicated by 1, 2, 3 or physique designation (M, L, XL) differed between shopping malls, and even in the same shopping mall, even if the same size notation was used. Most the clothing sizes were different depending on the type of clothing. For bottoms, it was found that one company used seven size designation methods at the same time, two shopping malls used four size designation methods, and five shopping malls used three size designation methods. In the meantime, in the results of comparing the size specifications of jeans XL (size 88, 32 inches) by product part, for waist and hip circumferences, each of the eight companies showed that the size was smaller than the body size suggested by KS adult women's wear.