• 한국멀티미디어학회논문지
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• 제2권3호
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• pp.355-365
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• 1999

본 연구에서는 배열 데이터를 여러 호스트 상에 분산시켜 생성하고 편리하게 공유할 수 있도록 하는 Java 패키지인 JPAS (Java Package for Array Sharing)를 설계하고 구현하였다. JPAS는 순수 Java로 구현되어 이식성이 뛰어나고, Java RMI를 이용하여 분산공유메모리 모델과 같이 위치 독립적인 접근 인터페이스로 배열 데이터를 공유할 수 있도록 한다. JPAS는 네트원 오버헤드로 인한 성능 저하를 막기 위해서, 프로그래머 가 알고 있는 애플리케이션의 특성을 공유 데이터 사용시에 반영할 수 있도록 한다. 또한, 데이터의 일관성을 유지하기 위해서, JPAS의 모든배열 데이터들은 값을 갱신 할수 있는 메소드틀을 갖는다. 실제로, 병렬프로그램들을 작성하여 워크스테이션 클러스터 상에서 실행시켜 본 결과, JPAS가 비교적 우수한 성능의 병렬 프로그래밍 도구임을 보였다.

• 대한공간정보학회지
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• 제17권4호
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• pp.113-119
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• 2009

유비쿼터스(Ubiquitous) 정보화 사회에서는 공간정보에 대한 실제적인 모습과 정확한 위치정보가 요구되고 있다. 공간정보의 대국민 서비스가 이뤄지기 위해서는 공간정보의 표준화가 필요하다. 국제표준(International Standard)은 세계 각국에서의 각종 규격 기술 용어 등의 호환성을 확보하고 상호교역을 촉진시키기 위해 일정한 기준과 표준 형태를 국제 간 합의를 통해 규정해 놓은 것을 말한다. 국제표준안은 국제표준화기구(ISO : International Organization for Standardization)에서 제정하고, 지리정보분야의 국제 표준안은 ISO TC(Technical Committee) 211 에서 담당한다. ISO TC 211에서 추진 중인 토지행정도메인 모델(LADM : Land Administration Domain Model)은 토지와 관련된 행정 법, 공간 측량 등의 국제표준화를 제정하여 각 국가의 토지 관련 시스템과 데이터를 효율적으로 관리하고자한다. 본 논문에서는 토지행정도메인 모델 부분 중에서 측량과 관련된 표준화 진행 상황과 내용을 소개하고 국내지적정보모델을 비교 연구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.366-369
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• 2003

The vertical fountain plating system with the point contact has been used in semiconductor industry. But the plating shape in the opening of photoresist becomes gradated shape, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. So, we designed the tilted electrode ring contact to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and $\alpha$-step. A photoresist was coated to a thickness of $60{\mu}m$ and vias were patterned by a contact aligner After via opening, solder layer was electroplated using the fountain plating system and the tilted electrode ring contact system. In $\alpha$-step measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were ${\pm}16%,\;{\pm}3.7%$ respectively. In this study, we could get high uniformity bumps by the tilted electrode ring contact system. So, tilted electrode ring contact system is expected to improve workability and yield in module process.

• Journal of Power Electronics
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• 제13권2호
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• pp.322-328
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• 2013

This paper presents a modified Current Source Parallel Resonant Push-pull Inverter (CSPRPI) for single phase induction heating applications. One of the most important problems associated with current source parallel resonant inverters is achieving ZVS in transient intervals. This paper shows that a CSPRPI with the integral cycle control method has dynamic ZVS. According to this method, it is the Phase Locked Loop (PLL) circuit that tracks the switching frequency. The advantages of this technique are a higher efficiency, a smaller package size and a low EMI in comparison with similar topologies. Additionally, the proposed modification results in a low THD of the ac-line current. It has been measured as less than %2. To show the validity of the proposed method, a laboratory prototype is implemented with an operating frequency of 80 kHz and an output power of 400 W. The experimental results confirm the validity of the proposed single phase induction heating system.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.437-442
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• 2005

In this paper, we proposed the 2-dimensional inspection algorithm for micro-BGA(Ball Grid Array) device using a vision system. The proposed method uses the subpixel algorithm for high precision. The proposed algorithm preferentially extracts the package area of device in the input image. After the extraction of package area, each ball areas are extracted by ball search window method. The parameters for inspection are calculated for the extracted ball area. In the simulation results, we have the average error within $17{\mu}m$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1442-1447
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• 2003

Computer is a very powerful machine which is widely using for data processing, DB construction, peripheral device control, image processing etc. Consequently, many researches and developments have progressed for high performance processing unit, and other devices. Especially, the core units such as semiconductor parts are rapidly growing so that high-integration, high-performance, microminiat turization is possible. The packaging in the semiconductor industry is very important technique to de determine the performance of the system that the semiconductor is used. In this paper, the inspection of the inner defects such as delamination, void, crack, etc. in the semiconductor packages is studied. ESPI which is a non-contact, non-destructive, and full-field inspection method is used for the inner defect inspection and its results are compared with that of C-Scan method.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.1-12
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• 2009

Presently, the semiconductor industry has the chronic problem. In the semiconductor industry, it has the semiconductor wafer, a package, the optical filter cut by using the saw blade, the mold, a laser etc. The cutting technique has the difficulty due to the rising of the production cost by the wearing of mold, the poor quality problem due to generated heat at the moment of cutting procedure and curve cutting etc. The goal of this time of national research and development project is develop the apparatus for solving the problem that the existing cutting technique has. The technology is so called waterjet abrasive method. This technology will be mainly applied to cut a semiconductor package and a wafer. Two important things to be considered are ripple effect(in other words, the scale of a market) and simplicity of an application.

• ETRI Journal
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• 제33권5호
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• pp.802-805
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• 2011

This letter presents a K-band polarization reconfigurable antenna integrated with a silicon radio frequency MEMS switch into the form of a compact package. The proposed antenna can change its state from linear polarization (LP) to circular polarization (CP) by actuating the MEMS switch, which controls the configuration of the coupling ring slot. Low-loss quartz is used for a radiating patch substrate and at the same time for a packaging lid by stacking it onto the MEMS substrate, which can increase the system integrity. The fabricated antenna shows broadband impedance matching and exhibits high axial ratios better than 15 dB in the LP and small axial ratios in the CP, with a minimum value of 0.002 dB at 20.8 GHz in the K-band.

• Wind and Structures
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• 제28권3호
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• pp.171-180
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• 2019

This paper presents a restart iterative approach for time-domain flutter analysis of long-span bridges using the commercial FE package ANSYS. This approach utilizes the recursive formats of impulse-response-function expressions for bridge's aeroelastic forces. Nonlinear dynamic equilibrium equations are iteratively solved by using the restart technique in ANSYS, which enable the equilibrium state of system to get back to last moment absolutely during iterations. The condition for the onset of flutter instability becomes that, at a certain wind velocity, the amplitude of vibration is invariant with time. A long-span suspension bridge was taken as a numerical example to verify the applicability and accuracy of the proposed method by comparing calculated results with wind tunnel tests. The proposed method enables the bridge designers and engineering practitioners to carry out time-domain flutter analysis of bridges in commercial FE package ANSYS.

• ETRI Journal
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• 제46권3호
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• pp.473-484
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• 2024

We introduce a machine learning-based web application to help travel agents plan a package tour schedule. K-nearest neighbor (KNN) classification predicts the optimal tourists' dwelling time based on a variety of information to automatically generate a convenient tour schedule. A database collected in collaboration with an established travel agency is fed into the KNN algorithm implemented in the Python language, and the predicted dwelling times are sent to the web application via a RESTful application programming interface provided by the Flask framework. The web application displays a page in which the agents can configure the initial data and predict the optimal dwelling time and automatically update the tour schedule. After conducting a performance evaluation by simulating a scenario on a computer running the Windows operating system, the average response time was 1.762 s, and the prediction consistency was 100% over 100 iterations.