• 대한전기학회논문지:시스템및제어부문D
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• 제53권2호
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• pp.94-102
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• 2004

The digital electronic switching system has some problems, when this system processes OAM(Operation, Administration And Maintenance) messages about the fault, the traffic, the account, and the performance, etc., at the present. One of these problems is that each the module processing these messages in the digital electronic switching system can not process OAM messages out of another digital electronic switching system. Each the module processing these OAM messages, that is, has been programmed in order to process only the OAM message out of the digital electronic switching system mounting itself, not to process the message out of the digital electronic switching system based on another platform. Therefore, we studied on methods that could process OAM messages out of all digital electronic switching systems and, first of all, developed the MGS(Message Gathering System) to be able to accept and process the fault message of OAM messages out of all digital electronic switching systems in real time.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.229-232
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• 1998

Modern telecommunications are increasingly demanding the addition of complex switching features to switching system software. These improvements also should satisfy customer demands for quick provisioning of new service features. But whenever we have developed the switching system in various types, we met problems that are lack of system engineers and short developments terms. We need new guidelines of software design to meet the demands and overcome our problems. So we propose new software platform, scenario driven call control engine (SDCCE) for ATM switching system software and implement an effective call control software using scenarios for ATM Switching System. A scenario is a set of procedures and supplementary scenarios written in data structure and gives benefits to easy adapt new or modified function by adding a scenario. The goal of SDCCE is to increase reusability and readability of software. Especially, it gives a good software extensibility and maintainability. And when we developed ptmp call processing control software, we could get high productivity by reusing scenarios and procedures of ptp call processing control software. We applied the scenario driven call control software to ATM switching system.

• 대한치과보철학회지
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• 제49권4호
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• pp.346-353
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• 2011

연구 목적: 임플란트 식립 후 변연골 흡수에 따라 임플란트 주위 연조직이 재구성되며, 이에 따라 치료의 예후 및 심미성 등에 영향을 주게 된다. 그러므로 임플란트 경부 주위 골조직 보존을 위한 임플란트 경부에 다양한 디자인이 연구되고 있다. 본 고찰의 목적은 초기 변연골 흡수의 원인과 이에 따른 임플란트 주위의 연조직 변화에 대해 고찰하고, 어떠한 임플란트 경부 디자인이 임플란트 주위 조직의 보존에 유리한 지 알아보고자 한다. 연구 재료 및 방법: Pubmed database에서 임플란트 초기 변연골 흡수의 원인과 관련된 논문과 임플란트 경부의 여러 디자인에 관한 논문을 검색하여 분석하였다. 임플란트 경부 디자인은 one piece implant, two piece implant, internal hex abutment, external hex abutment, taper joint connection, butt joint connection, scalloped design abutment, platform switching concept에 관해 검토하였다. 결과: 초기의 임플란트 주위 조직 보존에 대하여 one piece implant가 two piece implant보다 유리한 것으로 여러 임상적, 실험적 연구가 있다. Two piece implant에서는 internal hex abutment가 external hex abutment보다, taper joint connection가 butt joint connection보다 유리할 것으로 보여진다. Scalloped design abutment에 대해서는 논쟁의 여지가 있어 더 많은 연구가 필요할 것으로 판단된다. Platform switching concept은 그 원인이 명확히 밝혀지지는 않았으나 임상적, 실험적으로 초기 임플란트 주위 조직 보존에 대해 유리한 것으로 판단된다. 결론: 임플란트 경부의 디자인마다 각각의 장단점이 있고 추가적인 연구가 더 필요한 제한이 있지만 현재까지의 선행 연구들을 분석 종합해 보면 초기 임플란트 주위 조직 보존을 고려한다면 가능한 경우 one piece implant가 유리할 것으로 판단되며, 보철적인 문제나 다른 이유로 인하여 two piece implant를 고려할 경우 platform switching concept, internal connection abutment, taper joint connection을 이용하는 것이 임플란트 주위 조직 보존에 좀더 유리할 것으로 사료된다.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2006년도 제46회 종합학술대회 연제초록
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• pp.135-135
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• 2006

• 스마트미디어저널
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• 제1권4호
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• pp.44-51
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• 2012

본 논문은 휴대단말을 위한 차세대 인터페이스 기술을 수용하기 위한 지능형 사용자 인터페이스 플랫폼인 SUIP를 기술한다. SUIP 플랫폼은 안드로이드 플랫폼을 확장하여 새로운 인터페이스 장치를 수용할 수 있도록 개발되었다. 새로운 인터페이스에 대한 응용 개발을 위하여 소프트웨어 모듈의 동적 로딩 기능을 지니고 있다. 또한, 사용자 인터페이스 품질을 높이기 위한 외부 장치 활용을 위한 플래폼 기술과, 서비스에 따른 전력 소모를 줄이기 위한 동적 인터페이스 스위칭 기술도 포함하고 있다.

• Journal of Power Electronics
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• 제18권4호
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• pp.1255-1267
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• 2018

Parasitic parameters have a larger influence on Silicon Carbide (SiC) devices with an increase of the switching frequency. This limits full utilization of the performance advantages of the low switching losses in high frequency applications. By combining a theoretical analysis with a experimental parametric study, a mathematic model considering the parasitic inductance and parasitic capacitance is developed for the basic switching circuit of a SiC MOSFET. The main factors affecting the switching characteristics are explored. Moreover, a fast-switching double pulse test platform is built to measure the individual influences of each parasitic parameters on the switching characteristics. In addition, guidelines are revealed through experimental results. Due to the limits of the practical layout in the high-speed switching circuits of SiC devices, the matching relations are developed and an optimized layout design method for the parasitic inductance is proposed under a constant length of the switching loop. The design criteria are concluded based on the impact of the parasitic parameters. This provides guidelines for layout design considerations of SiC-based high-speed switching circuits.

• Asia Marketing Journal
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• 제19권4호
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• pp.61-85
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• 2018

Open innovation is based on a different knowledge landscape, with a different logic about the sources and uses of technologies. It implies that firms increasingly rely on external sources of innovation by emphasizing these ideas and resources. Using datasets from the UK biotechnology industry, this paper explores firms' willingness to participate in open innovation. The results indicate that the switching cost is identified as the direct predictor of the willingness to participate in open innovation. While high commitment based on the trust with partner increases switching costs, IT infrastructure within the firm decreases switching costs to open innovation. Taken together, this research broadens the study on open innovation by applying the switching cost as a medium of knowledge transfer in the biotech industry.

• 대한임베디드공학회논문지
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• 제7권2호
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• pp.61-70
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• 2012

This paper describes terrain-adaptive attitude controller for a hybrid mobile platform which operates in wheel & track mode. The wheel mode of the hybrid mobile platform allows quick driving performance in the flatland, while the track mode provides adaptive movement in the rough ground or stairway. The switching of the platform between two modes is automatically controlled by attitude controller algorithm. In addition, in the track mode, the platform automatically adjusts its attitude angle to overcome the obstacles in front. This paper demonstrates the attitude controller for the aforementioned wheel-track hybrid mobile platform in order to overcome terrain obstacles by using an adaptive method. The driving performance of the hybrid mobile platform has been tested and verified in various surrounding environments in both wheel and track mode. Further, this paper presents the experiments by using the track structure of mobile platform on forming adaptive attitude under various types of obstacles. The practicability and effectiveness of the proposed attitude controller of the platform has been demonstrated in urban building and a test-bed.

• Smart Structures and Systems
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• 제25권5호
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• pp.559-567
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• 2020

Vibration at the tip of various flexible manipulators may affect their operation accuracy and work efficiency. To suppress such vibrations, the feasibility of using MFC actuators and sensors is investigated in this paper. Considering the convergence of the famous filtered-x least mean square (FXLMS) algorithm could not be guaranteed while it is employed for vibration suppression of plants with varying secondary path, this paper proposes a new multiple model switching adaptive control algorithm to implement the real time active vibration suppression tests with a new multiple switching strategy. The new switching strategy is based on a cost function with reconstructed error signal and disturbance signal instead of the error signal from the error sensor. And from a robustness perspective, a new variable step-size sign algorithm (VSSA) based FXLMS algorithm is proposed to improve the convergence rate. A cantilever beam with varying tip mass is employed as flexible manipulator model. MFC layers are attached on both sides of it as sensors and actuators. A co-simulation platform was built using ADAMS and MATLAB to test the feasibility of the proposed algorithms. And an experimental platform was constructed to verify the effectiveness of MFC actuators and sensors and the real-time vibration control performance. Simulation and experiment results show that the proposed FXLMS algorithm based multiple model adaptive control approach has good convergence performance under varying load conditions for the flexible cantilever beam, and the proposed FX-VSSA-LMS algorithm based multiple model adaptive control algorithm has the best vibration suppression performance.

• Journal of Power Electronics
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• 제18권6호
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• pp.1729-1750
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• 2018

Voltage source inverters (VSIs) are widely used to drive induction motors in industry applications. The quality of output waveforms depends on the switching sequences used in pulse width modulation (PWM). In this work, all existing optimal space vector pulse width modulation (SVPWM) switching strategies are studied. The performance of existing SVPWM switching strategies is optimized to realize a tradeoff between quality of output waveforms and switching losses. This study generalizes the existing optimal switching sequences for total harmonic distortions (THDs) and switching losses for different modulation indexes and reference angles with a parameter called quality factor. This factor provides a common platform in which the THDs and switching losses of different SVPWM techniques can be compared. The optimal spatial distribution of each sequence is derived on the basis of the quality factor to minimize harmonic current distortions and switching losses in a sector; the result is the minimum ripple loss SVPWM (MRSLPWM). By employing the sequences from optimized switching maps, the proposed method can simultaneously reduce THDs and switching losses. Two hybrid SVPWM techniques are proposed to reduce line current distortions and switching losses in motor drives. The proposed hybrid SVPWM strategies are MRSLPWM 30 and MRSLPWM 90. With a low-cost PIC microcontroller (PIC18F452), the proposed hybrid SVPWM techniques and the quality of output waveforms are experimentally validated on a 2 kVA VSI based on a three-phase two-level insulated gate bipolar transistor.