• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.67-74
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• 1997

A relationship between drying resistance and moisture content was found for 24, 27 and 30mm thick boards, and 45, 51 and 57mm thick dimensions of Japanese larch. Dahurian larch and radiata pine in order to modify the kiln schedule by using time schedules. The amount of drying resistance for Dahurian larch lumber was the highest, and radiata pine lumber was the lowest, on the basis of the same moisture content range. Drying resistance increased curvilinearly as moisture content decreased, and was higher for thicker lumber than for thinner lumber, at a given moisture content. Combined drying resistance for the three board thicknesses and the three dimension thicknesses showed a comparatively strong for radiata pine and a Japanese larch, while a weak correlation for Dahurian larch as a function of two independent variables, thickness and moisture content of lumber, respectively.

• The Journal of Aerospace Industry
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• s.69
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• pp.88-98
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• 2007

서머타임은 1784년 벤자민 프랭클린에 의해 최초 제안된 이후, 제1차 세계대전중인 1916년 5월 1일 독일과 오스트리아에서 최초 도입되었고, 현재 전세계적으로 86개국 이상이 서머타임을 실시하고 있다. 우리나라의 경우 1948년 처음 도입하여 1960년까지 시행 하였으며, 이후 1987년 산업의 고도화와 올림픽 개최에 맞추어 동 재도를 재실시하였으나 여러가지 긍정적 영향에도 불구, 권위주의 정부의 국민의견 수렴이 없는 일방적 결정과 당시 미성숙된 노동자 근무여건, 특히 올림픽 경기의 외국 TV 방송시간에 맞추기 위한 올림픽용이라는 비판 등 국민적 거부감으로 시행 2년 후인 1989년 폐지되었다. 최근 사회적 여건의 성숙에 따라 서머타임 도입이 재 논의 되고 있으며, 서머타임이 도입될 경우 약 31만명의 외국인 관광객 추가 방한과 연간 약 4,340억원 이상의 추가 관광수입을 얻을 수 있을 것으로 예상된다. 특히 항공운송산업의 경우 100만명 이상의 국제선 탑승객 증가와 약 1,537억원의 항공운임 수입증가 효과를 거둘 수 있을 것으로 예상된다. 또한 항공운송산업 직접연관산업에서 약 400여명, 간접연관산업에서 3,000여명 등 항공운송산업 전체에서 총 3,400여명의 고용 효과를 유발할 것이다. 반면 서머타임 도입에 따라 CRS, GDS, 항공기 스케쥴, 운항·항행 시스템 및 각 공항별 Curfew 조정이 필요하나, 이미 전세계 항공 선진국 대부분이 수십여년간 서머타임을 도입하고 있어, 서머타임 도입에 따른 失이나 혼란보다는 得과 효용이 더 클 것으로 생각된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.263-266
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• 2012

This paper describes an efficient hardware implementation of Whirlpool hash function as ISO/IEC 10118-3 standard. Optimized timing is achieved by using pipelined small LUTs, and Whirlpool block cipher and key schedule have been implemented in parallel for improving throughput. In key schedule, key addition is area-optimized by using inverters and muxes instead of using rom and xor gates. This hardware has been implemented on Virtex5-XC5VSX50T FPGA device. Its maximum operating frequency is about 151MHz, and throughput is about 950Mbps.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1119-1129
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• 1998

This paper proposes a method to estimate the time to execute a hypermedia scenario. The method builds a PNDT(Petri Net with probability Distribution Table) model for the flow of the scenario, then performs Monte Carlo Simulation on the PNDT model to estimate the duration time from the start to the end of the scenario. The estimated times to execute scenarios are useful to both information providers and users. A user can make a better time plan referring to them, and an information provider can make the most efficient scenario-presentation schedule for users referring to them. However, no research results regarding this subject have been reported yet.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.66-72
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• 2008

During the plate and foil cold rolling process, considerable values of the force of material pressure on the tool occur. These pressures cause the elastic deformation of the roll, thus changing the shape of the deformation legion. Rolled copper foils should be characterized by a good quality and light dimensional tolerances. Because of automation that is commonly implemented in flat product rolling mills, these products should meet the requirements of tightened tolerances, particularly strip thickness, and feature the greatest possible flatness. The shape of the roll gap is influenced by the elastic deformation of rolls parts of the rolling process affecter of the pressure force. However, to control roll deformation should be difficult. Because the foil thickness is very thin and the permissible deviations in the thickness of foil are small. In this paper, FE-simulation of roll deformation in thin foil cold roiling process is presented.

• Transactions of Materials Processing
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• v.4 no.4
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• pp.375-389
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• 1995

In H shape rolling, accurate predictions of deformation and temperature distribution in a billet are quite important because they are the main factors in determining roll calibers and roll pass schedules. Many researches have been performed to achieve the predictions, but most of them are limited to single pass or isothermal assumptions. In the present investigation, it is attempted to develop a method to predict the deformation and temperature distributions which is applicable to a complete rolling process that usually consists of several rollings under different rolls for a period of time. The method works by coupling two analyses : one is an approximate analysis for temperature distribution prediction and the other is the slab-FEM hybrid analysis for deformation prediction. The method is applied to analyze a "H" shape rolling process consisting of nine passes under four different rolls. In the present paper, basic ideas of the method are presented. Also, shapes of cross sections, strain and temperature distributions, roll separating force and roll torque predicted by the method are discussed.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.113-119
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• 1987

A study was conducted to determine the kiln drying schedule for hydrid aspen, This kiln drying schedule was found by oven drying method and developed by pilot testing of 2.0cm, 2.5cm, 3.0cm-thick green lumber. The results of this study were as follows: 1. Kiln drying schedule developed by oven-drying method was $T_{12}-E_5$ for 2.5cm-thick green lumber. 2. Drying times for 2.0cm-thick green lumber(127.0 percent moisture content) to 7.3 percent moisture content, for 2.5cm-thick green lumber(95.0 percent moisture content) to 9.7 percent moisture content, and for 3.0cm-thick green lumber(118.5 percent moisture content) to 10.0 percent moisture content were 45 hours, 45 hours, and 54 hours, respectively. 3. Drying rate from 90 to 10 percent moisture content of 2.5cm-thick lumber was about 0.7 times faster than that of 2.0cm-thick lumber and about 1.1 times faster than that of 3.0em-thick lumber. 4. End checks for 2.0cm-, 2.5cm-, and 3.0cm-thick green lumber occurred 95, 74 and 100 percent moisture content, respectively and reached maximum amount in 53, 41, and 60 percent moisture content, respectively. 5. No surface check and no honeycomb occurred. 6. Cupping and collapse slightly occurred and the quality of dry lumber was first.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.331-334
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• 2010

Operating characteristics of DGT-5 being developed by Doosan Heavy Industries & Construction Co., Ltd. for power generation service was evaluated. Starting behavior was improved by a series of tests to investigate the effect of various fuel schedule and several combination of bleed valve control. The engine showed stable operation without any instability of compressor in the full operating regime covering from start-up to load conditions. If there is a rapid change of load in the condition of synchronization to Grid, the engine can be controlled stably based on the analysis of dynamic responses of the engine to an rapid load change and a sudden load rejection.

• Annual Conference of KIPS
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• 2015.10a
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• pp.297-300
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• 2015

이 논문에서는 가축관리의 효율성을 높일 수 있는 IoT 기술 기반의 지능형 축산정보 통합관리 시스템 및 구축 방안을 제안한다. 제안한 시스템은 체온, 활동량, 군집도와 같은 개체특성 정보와 온도, 습도, CO2 농도 등의 축사환경 정보를 무선센서 네트워크를 통해 실시간으로 수집한다. 수집된 정보는 가축개체별 생애주기 사양관리 스케쥴과 연동되어 신속한 관리가 필요한 이상상황을 자동으로 인식한다. 또한, 축적된 양질의 축산지식 정보는 허가된 범위 내에서 접종사, 수정사, 수의사, 축산공무원 등 축산종사자에게 공유된다. 제안한 시스템은 대규모 축사에서 수정, 분만, 질병관리 등 사양관리 시기를 자동으로 감지하여 축주에게 알려줄 수 있기 때문에 최소한의 시간과 비용으로 가축관리 효율성과 생산성을 높일 수 있다.

• Journal of the Korea Computer Industry Society
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• v.2 no.7
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• pp.923-932
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• 2001

In this paper, An imprecise real-time task sets composed of multimedia datas are generated using several parameters and an algorithm which can analyse schedulability of generated imprecise real-time task sets before execution of this task sets is proposed. Also, The schedulability of task set depends on variation of parameter values which were used during the generation of the task set is studied. As a result of experiment, It isproved that the schedulability of task set is more and more weak as large as execution requirement time of mandatory subtasks and, as many as the number of tasks which can be scheduled at some instant. The schedulabilty analysis algorithm which is presented on this paper is expected to use effectively on QoS service of multimedia datas.