• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.04a
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• pp.341-346
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• 1991

주물이 대형이고 난이한 자유곡면으로 이루어진 형상의 목형 제작에는 기준이 되는 각 단면의 도형 정보를 기초로 골격을 세워 그 틈새를 유연한 재료(모래, 시맨트, 스티로폴, 목재)로 메워 모형을 만드는 골격형 목형(Skeleton pattern)를 사용하여 왔다. 그러나 기준 단면사이의 형상보간 및 필요단면 정보는 틈새 메움시 현장 작업자의 수작업에 의존하여 작업되므로 제품 완성시 두께 분표불량등 정확한 주물을 제작할 수 없었다. 그러나 3차원 CAC 시스템의 발전과 더불어 자유곡면의 생성 및 조작이 손쉽게 이루어 짐으로써 정확한 형상 정의 및 처리가 가능하게 되어 기존 목형방법을 개선할수 있는 시스템을 개발하여, 프로펠라 목형을 대상으로하여 적용하였다.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.120-128
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• 2015

This study reports the combustion characteristics, such as burner temperature and the concentration of exhausted gas ($O_2$, $CO_x$, $NO_x$) due to the different types and pitches of the fuel supply feeder of the wood pellet boiler. The 1st grade wood pellets composed of mainly larch have been used for the experiment. In case of using the spring feeder, mean temperature of burner was approximately $821.76^{\circ}C$, and the mean concentration of oxygen, carbon monoxide, carbon dioxide and nitrogen oxide were approximately 8.88%, 93.35ppm, 12.15% and 139.83 ppm, respectively. The test result with the spring feeder was shown to approach the condition of complete combustion compared to that of a screw feeder and were in good agreement with authentication judgement standard. Furthermore, the combustion efficiency was improved according to the growth of screw pitch. The control of air flow rate from the blower and ventilator is needed to achieve the complete combustion.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.71-80
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• 1996

Handling the manufacured goods is the most cost-consuming task in material handling system in wooden furniture industries. Fully automated warehouse for cartoned goods of a furniture manufacturing company was analized to provide plant engineers and managers with some important informations on the utility and profitability of the automated storage and retrieval system(AS/RS). Process-oriented simulation modeling tech-niques were used to describe the system and to propose some alternatives to promote the efficiency of AS/RS. Simulation report could be inter-preted as follows: 1. Warehouse for the furniture goods must be designed in accordance with reliable material handling program and constructed with suitable equipments depending on the specification of packed products. 2. An excess of palletized products induced the indigestion and the inefficiency of AS/RS of the furniture industry and put this high-costly system into the shade. 3. Overcrowded AS/RS of the furniture factories could regain its material handling function by cutting down the deposit of products into the automated warehouse. For this purpose, reducing the regular output and direct delivering the outside products to the destination should be considered as the definite counterplan. And additional operation of conventional handy warehouse was also expected to improve the efficiency of main AS/RS.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.279-282
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• 2004

본 논문에서는 자기저항 센서를 이용하여 자율주행 시스템에서 필요로 하는 자석의 종류에 따른 자계의 특성을 분석하였다 분석결과 거리에 따라 자계의 특성이 변화하고, 자석에 근접할수록 자계의 변화가 급격하게 나타난다. 센서가 자석에서 멀어질수록 지자계의 값에 가까워진다 또한 페라이트자석 보다 네오디뮴 자석의 자계특성이 우수함을 보였다.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.512-520
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• 2011

This study was preformed to investigate the characteristics of the green drying system for utilizing heat wasted during carbonization process. The green drying system utilizing waste heat is one of environment-friendly equipments because it needs no other energies from fossil fuel and etc. In this study, waste heat from three kilns was collected by stainless connection pipe, and in the green drying system the temperature and humidity was hardly changed. Charcoal charecteristics as fixed carbon, refining degree, hardness, pH, calorific value, and charcoal yield were analyzed to investigate kiln performance due to installation of green drying system. As a result, the green dry system installation hardly affected the characteristics of charcoal. In conclusion, the green drying system can be applied to maximize the profit of the farm household income and contribute to reduce fossil energy.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.230-238
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• 2015

This study was analyzed the operational cost of logging and chipping operations in order to develop the efficient logging operation system for the utilization of forest-biomass. Analysis of the operational cost of logging operation systems, the operation system D which include chain saw, tower-yarder, mini-forwarder and truck was calculated the lowest cost to be $68,498Won/m^3$. In the utilization of forest-biomass, the operation system E which include chipping by mini-chipper at the site, forwarding of chips by mini-forwarder, transportation of chips by truck was estimated to be 90,770 Won/Ton. Thus, These results are determined as an effective operating system for logging operation and the utilization of forest-biomass.

• Journal of Conservation Science
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• v.37 no.3
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• pp.220-231
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• 2021

The use of digital copies of film-based analog images and the introduction of digital radiographic imaging systems using image plates gradually replace the non-destructive radiationirradiation method of Cultural Heritage. The quality of images obtained from this technique is affected by conditions such as tube voltage, tube current, and exposure time, type of image acquisition medium, distance of the artifacts from the image acquisition medium, and thickness of artifacts. In this study, we evaluated the grayscale image obtained using GE's Computed Radiograhpy (CR) imaging system, the transmission characteristics of the X-ray source for each tree type (pine, chestnut, sawtooth oak, ginkgo) used in wooden Cultural Heritage, and the signal-to-noise ratio (SNR) and contrast. The GE's CR imaging were analyzed using the Duplex wire image quality indicator, line-pair gauges.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.174.2-174.2
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• 2011

최근 유가상승과 석유, 천연가스의 가채 매장량의 한계등과 함께 온실가스에 의한 지구온난화 방지를 위하여 미국, 유럽국가 및 캐나다 등에서는 바이오매스를 이용한 에너지 회수 기술개발에 많은 관심과 연구를 수행하고 있다. 바이오 매스는 에너지 밀도 대비 존재하는 지역이 광범위하여 발생, 수집, 수송에 따른 비용이 많이 소요되는 특성이 있어 산지에서 직접처리하거나 수집하여 대규모처리등과 같이 여러 가지 현장상황에 따라 적정한 플랜트 운용의 유연성을 갖추고 있어야 한다. 일반적으로 바이오매스로부터 중소형으로 분산형 발전이나 수소제조를 위해서는 직접 연소법 보다는 가스화 방식을 이용하고 있는데, 연소에 의해 열을 생산하여 전기를 생산하는 방식은 스팀터빈을 이용하는 것이며, 스팀터빈은 소형 운용이 어렵기 때문이다. 본 연구에서는 폐목재로부터 합성가스제조를 위하여 5톤/일 규모 가스화기를 제작하였으며, 타르 및 수트와 같은 미반응 물질을 제거할 수 있는 집진, 세정장치를 설계 및 제작하였다. 또한 합성가스에 함유된 현열로부터 열회수를 위하여 열교환기를 설치하였으며, 정제된 합성가스를 이용하는 가스엔진을 통하여 열병합 발전시스템 연계운전을 수행하였다. 운전 실험을 폐목재 가스화 3톤/일 규모로 수행하였으며, 평균 1,500kcal/$Nm^3$의 발열량을 갖는 합성가스를 생성시킬 수 있었다. 사이클론, 스크러버 및 기수분리 장치를 이용하여 정제된 합성가스는 합성가스 엔진을 통하여 72kW 이상의 전력생산이 가능하였다. 열교환기를 통하여 평균 15,000kcal/h의 배열 회수가 가능하였으며, 바이오매스 가스화 합성가스를 이용한 열병합 발전이 가능함을 입증하였다.

• Journal of Korean Society of Steel Construction
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• v.18 no.2
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• pp.251-259
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• 2006

In some cases, wooden structures are used for medium-rise buildings. It is therefore necessary to develop and test a new structural system for medium-rise buildings using wooden structures. This study deals with high-performance, laminated, timber-based composite members, which consist of structural laminated timber and H-beam. Simple beam tests were performed to determine the strength, stress distributions, and failure patterns of laminated timber. The main parameters are the insertinglength (1, 1.5, and 2 times the H-beam height) and the epoxy between the top/bottom flange of the H-beam and the top/bottom flange of the laminated timber. The results of the test show that the specimen with an inserting length that is 2 times the H-beam height was characterized by fairly god strength and stiffness.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.311-316
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• 2008