• Journal of information and communication convergence engineering
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• 제1권4호
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• pp.177-182
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• 2003

Conventional multilayer feedforward artificial neural networks are very effective in dealing with spatial problems. To deal with problems with time dependency, some kinds of memory have to be built in the processing algorithm. In this paper we show how the newly proposed Serial Input Neuron (SIN) convolutional decoders can be derived. As an example, we derive the SIN decoder for rate code with constraint length 3. The SIN is tested in Gaussian channel and the results are compared to the results of the optimal Viterbi decoder. A SIN approach to decode convolutional codes is presented. No supervision is required. The decoder lends itself to pleasing implementations in hardware and processing codes with high speed in a time. However, the speed of the current circuits may set limits to the codes used. With increasing speeds of the circuits in the future, the proposed technique may become a tempting choice for decoding convolutional coding with long constraint lengths.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.113-118
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• 2007

As the economic living standards are higher, the demands for more comfortable living space are also larger. In the response of this requirements, studies for improving indoor air environment have been conducted. In case of newly-built apartment buildings, the standard for the minimum ventilation to improve their indoor air quality was made. This study analysed the experimental results from the mock-up test of the hybrid ventilation system which is composed of natural and mechanical ventilation.

• 설비공학논문집
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• 제20권1호
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• pp.57-64
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• 2008

Recently, regulation of ventilator installation and its details has been revised and the establishment of heat recovery ventilator in newly built apartments has been obligated. This study was done to offer the method of operation and design of heat recovery ventilator to save energy by measuring its efficiency and comparing with the results of experiment. This paper confirmed that it is desirable to operate heat recovery ventilator by using "by-pass mode" within $60{\sim}80%$ scope of the difference indoor absolute humidity in spring and autumn and outdoor absolute humidity and heat recovery ventilator of energy saving effect is better than constant air volume system.

• Journal of Power Electronics
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• 제5권2호
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• pp.99-103
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• 2005

In this paper, a novel circuit topology of a three-winding coupling inductor-assisting a high-frequency PWM boost chopper type DC-DC power converter with a high boost voltage conversion ratio and low switch voltage stress is proposed for the new energy interfaced DC power conditioner in solar photovoltaic and fuel cell generation systems. The operating principle in a steady state is described by using its equivalent circuits under the practical condition of energy processing of a lossless capacitive snubber. The newly-proposed power MOSFET boost chopper type DC-DC power converter with the three-winding coupled inductor type transformer and a single lossless capacitor snubber is built and tested for an output power of 500W. Utilizing the lower voltage and internal resistance power MOSFET switch in the proposed PWM boost chopper type DC-DC power converter can reduce the conduction losses of the active power switch compared to the conventional model. Therefore, the total actual power conversion efficiency under a condition of the nominal rated output power is estimated to be 81.1 ％, which is 3.7％ higher than the conventional PWM boost chopper DC power conversion circuit topology.

• Wind and Structures
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• 제17권2호
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• pp.203-225
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• 2013

An analysis framework for vehicle-bridge dynamic interaction system under turbulent wind is proposed based on the relevant theory of wind engineering and dynamics. Considering the fluctuating properties of wind field, the stochastic wind velocity time history is simulated by the Auto-Regressive method in terms of power spectral density function of wind field. The bridge is represented by three-dimensional finite element model and the vehicle by a multi-rigid-body system connected by springs and dashpots. The detailed calculation formulas of unsteady aerodynamic forces on bridge and vehicle are derived. In addition, the form selection of wind barriers, which are applied as the windbreak measures of newly-built railways in northwest China, is studied based on the suggested evaluation index, and the suitable values about height and porosity rate of wind barriers are studied. By taking a multi-span simply-supported box-girder bridge as a case study, the dynamic response of the bridge and the running safety indices of the train traveling on the bridge with and without wind barriers are calculated. The limit values of train speed with respect to different wind velocities are proposed according to the allowance values in the design code.

• Smart Structures and Systems
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• 제29권4호
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• pp.561-576
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• 2022

Heritage timber structures represent the history and culture of a nation. These structures have been inherited from previous generations; however, they inevitably exhibit deterioration over time, potentially leading to structural deficiencies. Structural Health Monitoring (SHM) offers the potential to assess operational anomalies, deterioration, and damage through processing and analysis of data collected from transducers and sensors mounted on the structure. This paper reports on the design and implementation of a long-term SHM system on the Feiyun Wooden Pavilion in China, a three-story timber building built more than 500 years ago. The principles and features of the design and implementation of SHM systems for heritage timber buildings are systematically discussed. In total, 104 sensors of 6 different types are deployed on the structure to monitor the environmental effects and structural responses, including air temperature and humidity, wind speed and direction, structural temperatures, strain, inclination, and acceleration. In addition, integrated data acquisition and transmission subsystem using a newly developed software platform are implemented. Selected preliminary statistical and correlation analysis using one year of monitoring data are presented to demonstrate the condition assessment capability of the system based on the monitoring data.

• 한국전자파학회논문지
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• 제19권4호
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• pp.391-396
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• 2008

본 논문에서는 NRD 도파관 내에 표준 도파관에 대한 트랜지션 기능이 내장된 새로운 형태의 구형 도파관-NRD 도파관 트랜지션을 제안하였다. 새롭게 제안된 구형 도파관-NRD 도파관 트랜지션은 NRD 도파관 입출력측의 기구물 벽 두께와 개구부의 폭을 이용하여 구현된다. 벽 두께의 경우, NRD 도파관 관내 파장의 절반(${\lambda}_g/2$)과 거의 동일하며, 개구부의 폭은 NRD 도파관과 체결되는 표준 도파관의 넓은 변의 길이와 거의 일치한다. 이러한 원리는 주파수 대역과 무관하게 적용 가능하며, 본 논문에서는 38 GHz 대역에서 구형 도파관-NRD 도파관 트랜지션을 제작하여 타당성을 확인하였다. 38 GHz 대에서 제작된 구형 도파관-NRD 도파관 트랜지션은 back-to-back 구조에서 0.4 dB 이하의 삽입 손실과 20 dB 이하의 반사 손실을 갖는다.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.433-442
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• 2017

본 연구는 세종시 신설초등학교의 조리장 공간과 면적의 적정성에 관한 사례연구로 5개 학교의 조리장을 대상으로 공간구성과 면적을 비교분석하였다. 주요 결과로 조리장의 기준면적 대비 계획면적의 확보율은 A학교 99.2%, B학교 91.1%, C학교 81.4%, D학교 110.8%, E학교 88.1%로 세부적으로 조리실의 면적은 기준에 근접하거나 초과되어 계획되었지만 그 외의 실들은 계획되지 않거나 기준에 부족한 상황으로 대체적으로 부족한 면적을 확보하고 있었다. 검수실이 계획되지 않은 학교는 3개교로 전처리실과 겸용하면서 전처리실의 실제 사용면적이 감소하여 별도의 검수실 확보가 필요한 것으로 나타났다. 세척실은 세척과정의 특성상 최소 3.6m의 유효폭과 1.6m 이상의 통로폭이 요구되었으며 세척기구 반입동선을 고려하여 식당 및 조리실 방향으로 출입구를 확보해야 하는 것으로 분석되었다. 사용자 면담결과 공통적으로 조리/세척영역의 면적, 공간구성에 대해서 불만사항이 나타난 반면 보관 및 사용자영역에서는 불만을 제기하지 않았다. 이는 사용자들이 보관 및 사용자 영역보다 조리활동의 주요공간인 조리/세척 영역의 면적확보와 공간구성을 중요시하는 결과이며 현재의 조리장 기준 면적에서 각 영역 및 공간별 면적의 조정과 분배가 필요하다고 판단된다.

• 한국태양에너지학회 논문집
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• 제26권3호
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• pp.111-117
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• 2006

Song-do City is a newly constructed city built on land reclaimed from the seaside and the surrounding area. Its development involved a long process since the basic plans for reclamation of the publicly owned seaside area in Song-do were drawn up in September 1979. However, if we take a look at the overall status of the project as it is carried on at present, it is hard to deny that the project is trapped inside the same legal restrictions as are all other existing cities, which permits Song-do City to meet only very minimum standards. This study intends to analyze and assess the Song-do City's environmentally friendly construction and to rate its current development status, exposing any problems and offering alternative solutions. In this paper, the current state of constructions in Song-do City were reviewed. Then a quantitative analysis and assessment for the Song-do City constructions of apartments, complex buildings, office buildings, and school facilities were conducted by using green building certification criteria. Finally the synthetic results of environmental performance evaluation for Song-do city constructions and follow-up suggestions were described.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.106-115
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• 2007

In this study, first, child headform model was built up, satisfying requirement in the headform validation test. Also, for decreasing both acceleration peak and deformation, a new hood with dome shaped forming in inner panel was investigated. Next, headform impact, complying with draft of EEVC W/G 17, on the central portion of the newly proposed hood were simulated for a steel hood and three aluminum hoods with different thickness for examining the material and thickness effect on HIC value and inner panel deformation. The analysis results explained that aluminum hoods with dome shaped forming in inner panel were highly promising not only for meeting headform safety regulations but also for leading to weight savings. Finally, hood edge design technology in order to reduce pedestrian injury due to the high stiffness of beam type edge and the rigid support, was discussed. Various types of the foam filled edge were designed and their headform safety performance were evaluated. The edge structure with foam filled in upper one third of section exhibited excellent results.