• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1754-1764
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• 2004

Lately mobile handheld devices such as Personal Digital Assistant (PDA) and cellular phones are getting more popular for personal web surfing. However, today most mobile handheld devices have relatively poor web browsing capability due to their low performance so their users have to suffer longer communication latency than those of desktop Personal Computers (PCs). In this paper, we propose an effective pre-refresh mechanism for embedded web browser of mobile handheld devices to reduce this problem. The proposed mechanism uses the idle time to pre-refresh the expired web objects in an embedded web browser's cache memory. It increases the utilization of Central Processing Unit (CPU) power and network bandwidth during the idle time and consequently reduces the client's latency and web browsing cost. An experiment was done using a simulator designed by us to evaluate the efficacy of the proposed mechanism. The experiment result demonstrates that it has a good performance to make web surfing faster.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.607-610
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• 2003

The characteristic prediction and analysis of 3-dimensional (3-D) solenoid-type embedded inductors is investigated. The four different structures of 3-D inductor are fabricated by using low-temperature cofired ceramic (LTCC) process. The circuit model parameters of the each building block are optimized and extracted using the partial element equivalent circuit method and HSPICE circuit simulator. Based on the model parameters, predictive modeling is applied for the structures composed of the combination of the modeled building blocks. And the characteristics of test structures, such as self-resonant frequency, inductance and Q-factor, are analyzed. This approach can provide the characteristic conception of 3-D solenoid embedded inductors for structural variations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.77-78
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• 2010

As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling by PSIM simulator and investigates the influence on the grid-connected PV system from aspect of power quality, i.e. voltage drop. This paper includes four MPPT algorithms; Perturbation & Observation(P&O), Improved P&O, Increment Conductance(Incond), Hysterisis simulated with irradiation changing.

• ETRI Journal
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• 제28권3호
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• pp.347-354
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• 2006

The characteristic variation of 3-dimensional (3-D) solenoid-type embedded inductors is investigated. Four different structures of a 3-D inductor are fabricated by using a low-temperature co-fired ceramic (LTCC) process, and their s-parameters are measured between 50 MHz and 5 GHz. The circuit model parameters of each building block are optimized and extracted using the partial element equivalent circuit method and an HSPICE circuit simulator. Based on the model parameters, the characteristics of the test structures such as self-resonant frequency, inductance, and quality (Q) factor are analyzed, and predictive modeling is applied to the structures composed of a combination of the modeled building blocks. In addition, characteristic variations of the 3-D inductors with different structures using extracted building blocks are also investigated. This approach can provide a characteristic estimation of 3-D solenoid embedded inductors for structural variations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1301-1302
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• 2006

In this paper, embedded spiral inductors are investigated into the PCB substrate for low cost RF SOP applications. The spiral inductors designed with geometrical variations were simulated, fabricated, measured, and characterized by using 3D EM simulator, 8 layered PCB standard process and HP 8510B network analyzer (or verifying their applicability. The fabricated embedded spiral inductor has inductance of 9.4 nH at 800MHz, maximum quality factor of 64.8 at 1.09GHz and self resonant frequency of 3.93GHz, respectively. As the measured inductances and quality factors are well matched with simulated ones. PCB embedded spiral inductors are promising for advanced electronic systems with various functionality, low cost, small size and volume.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 추계학술발표대회
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• pp.372-374
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• 2019

기계를 잘 다루지 못하는 사람들은 스마트폰을 활용할 때 어려움을 겪는다. 따라서 기계에 서툰 사람뿐 아니라 날씨를 확인하기 힘든 바쁜 현대인들이 날씨를 시각적으로 좀 더 쉽게 확인하고, 필요한 용품을 미리 챙겨서 날씨에 대비할 수 있도록 한다. 그뿐만 아니라 사계절이 없는 나라의 사람들에게 다양한 계절을 경험할 수 있게 해준다. 터치스크린을 이용해서 사용자가 원하는 나라를 선택하면 날씨 정보가 화면에 나타나고, 날씨 박스에도 시각적으로 표현이 된다. 날씨 박스로는 인형 소품을 이용해 계절을 알려주고, 조명을 이용해서 황사, 미세먼지 그리고 낮과 밤을 나타내고, 효과음을 이용해서 비 또는 천둥을 표현한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 추계학술발표대회
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• pp.5-6
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• 2009

본 논문에서는 모바일 운영체제 또는 무선인터넷 플랫폼에 대한 독립성을 제공하는 가상화 기반의 모바일 시뮬레이터의 설계 및 구현에 대해 기술한다. 모바일 시뮬레이터는 단말에 최종 탑재되는 전체 SW 스택을 실제 단말 없이 데스크 탑 상에서 시험할 수 있는 환경을 제공한다. 그리고, 컨텐츠와 플랫폼의 안정성 테스트를 지원하기 위하여 사용자의 개입 없이 시뮬레이터에 의해 재현하는 이벤트 기반의 자동화 테스트를 지원한다.

• 한국해양공학회지
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• 제23권4호
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• pp.78-84
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• 2009

This paper presents development results of integrated operating program and its simulator for an inshore test miner. The inshore test miner drives on the seabed and collects manganese nodules. For operating the test miner, integrated operating program (IOP) is needed for remote control and monitor of the miner in real-time. However, it is hard to develop the practical IOP for the test miner system, because the system is big, expensive, and unique. So a simulator was developed as a test substitute in order to save time and to reduce cost. Using test results of the simulator, the IOP of the test miner was developed. The developed IOP consists of remote program, host program, monitoring program and database program. The operating program was developed using PXI and Labview of NI. The experimental results are presented to show the applicability of the developed program.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2003년도 추계종합학술대회 논문집
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• pp.181-184
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• 2003

예전의 영상처리 장비는 독립적으로 구현이 되었다고 하여도 단순히 디스플레이만 하는 정도였지만 현재 여러 가지 칩들의 발전으로 인한 그 응용에 있어 활용 범위가 다양해졌다. 본 연구에서는 아날로그 영상신호를 디지털로 컨버터 하여 PC없이 독립적으로 영상 데이터를 처리하는 시스템을 설계하고, 일반 아날로그 비디오 영상의 데이터에서 모션파라미터를 추출하여 시뮬레이터에 가상의 움직임을 만들어 낸다. 모션벡터를 추출하여 시뮬레이터를 구동하고, 영상 제어 알고리즘에 대하여 분석한다.

• International Journal of Railway
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• 제1권3호
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• pp.117-121
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• 2008

The personal rapid transit (PRT) system is a small scale transportation system that employs a novel concept to solve the traffic congestion problem in the city area. The PRT system is a driverless on-demand system that a passenger calls a vehicle rather than waits for the vehicle. Therefore, one of the most important issues in the PRT system is how to control the vehicle with the satisfaction of the basic concept of the PRT system. In this paper a computer simulator is introduced to evaluate the vehicle. operational control algorithm of the PRT system. The. computer simulator has the commercial embedded processor boards that operate in the real time operating system and pre-designed vehicle control algorithm is coded into the processor boards. The experimental results present the effectiveness of the proposed evaluation apparatus.