• Journal of Korean Society of Forest Science
• /
• v.73 no.1
• /
• pp.14-20
• /
• 1986

The processing times of the works, chainsaw felling, axe trimming and hand skidding to the corridor, by one-man-work method per single pole timber were investigated in the thinning young Japanese larch stand at the Training Forests of the Forest Work Tranining Center in Kangwon-do. The works were performed by a skilled worker with the craftman qualification and 69 trees were cut. Time was checked at intervals of 25/100 minute by the multimoment method and the worker's efficiency was evaluated for every cycle. Total working time was 8.11 hours of which 90% was for thinning work and 10% for cleaning work. Of the total working hours, 82.7% was net working time, 12.3% was general working time and 4.9% was non-valuated time. Of the net working time, 5.9hours, for only thinning, 20.9% was spent on moving to the feeling tree, 27.1% was spent on felling, 40.5% was spent on trimming and 11.5% was spent on skidding to corridor. Net chainsaw operating time was 0.94 hour which included 0.2 hour for cleaning work. Of the net chainsaw operating time, 0.94 hour, 66% was operating time and 34% was idle running time. The basic and general working times by DBH classes with application of 130% worker's efficiency calculated from regression equations were shown in table 1. For better practical using of this table, the simplified proposal was given in table 2.

• Proceedings of the Korean Society of Food and Cookery Science Conference
• /
• 2003.10a
• /
• pp.102-102
• /
• 2003

학교급식의 안전성을 도모하고자 도입된 HACCP 시스템 모든 형태의 급식소에서 중요하게 취급되나 성공적으로 적용(Implementation)하기 위해서는 급식소의 성격에 따라 1개의 메뉴에 1개씩 개발되어야 한다. 본 연구는 급식수가 비슷한 경북 농촌지역의 공동관리 초등학교(W, 133명 와 D, 143명)를 대상으로 2002년 12월에서 2003년 2월까지 메뉴(오징어덮밥)의 생산 공정도를 작성하고, HACCP을 적용하여 온도-시간 중심의 중점관리 기준을 포함한 생산 계획표를 작성하였다. 재료별 중점관리 기준은 냉동 오징어의 요리 전 처리의 해동 방법과 손질로 해산물 전용 도마의 구분과 지하수가 아닌 식수의 사용이며, 소요시간은 썰기 작업을 포함하여 1시간 15분을 초과하지 않도록 한다. (중략)

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.3
• /
• pp.3-10
• /
• 2011

Currently, technologies for industrialization and dissemination for Han-Ok are developed actively. Also BIM technologies are actively developed. However, it is difficult to find the research and study cases for construction method and process for Han-Ok. BIM is the technology for managing information with element as a unit for building design, construction and management, and it is closely related to Han-Ok using assembling method for building construction. We analyzed the basic construction processes for IK-Gong and MinDoRi house, typical types of Han-Ok. Also we developed the Work Breakdown Structure of construction process for Han-Ok and suggested the method for construction simulation using BIM. Simple BIM model of Han-Ok which is Ik-Gong type is used for case study. It was possible to link automatically between 3D elements objects and construction activities about 95% in the case study. More studies of construction method for various type of Han-Ok and rules for link between elements and construction activities are required for Industrialization and dissemination of Han-Ok.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.9
• /
• pp.54-61
• /
• 1998

A new Triple well structure is proposed for improved latch-up immunity at deep submicron CMOS device. Optimum latch-up immunity process condition is established and analyzed with varying ion implantation energy and amount of dose and also compared conventional twin well structure. Doping profile and structure are investigated using ATHENA which is process simulator, and then latch-up current is calculated using ATLAS which is device simulator. Two types of different process are affected by latch-up characteristics and shape of doping profiles. Finally, we obtained the best latch-up immunity with 2.5[mA/${\mu}{m}$] trigger current using 2.5 MeV implantation energy and 1$\times$10$^{14}$ [cm$^{-2}$ ] dose at p-well

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.434-437
• /
• 2003

In apartment project, BCWS is a critical management factor and has a great influence on the success of the project. But due to the characteristics of large apartment complex, there are several problems in making out a time schedule of work as well as production and management of precise bcws from the allocation of resources. In this study, Actual condition survey was executed in terms of the calculation and the management of BCWS. This study propose better solutions for efficient calculation of bcsw through the analysis of the problems and the origins relating to BCWS from a field area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.229-232
• /
• 2005

The study on the improvement of manufacturing process of RJ-4 liquid fuel that have high flash point, was carried out. In preparing of RJ-4 using commercially available MCPD, 1st, 2nd hydrogenation and isomerization reaction were enabled 1 step continuous process by combined use of heteropoly phosphoroustungstic cesium salt catalyst and 2nd stage-heat-controllable reactor. Also when heteropolyacid cesium salt was used as a isomerization catalyst instead of aluminum chloride, formation rate of exe-THDMCPD was higher, the catalyst could be easily separable from product and there was no production of waste acid, so this new reaction condition was confirmed as the environment friendly process.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.4
• /
• pp.431-436
• /
• 2005

This paper describes how to diagnose SBR plant equipment using time-series data mining. It shows the equipment diagnostics based upon vibration signals that are acquired front each device lot process control. Data transform techniques including two data preprocessing skills and data mining methods were employed in the data analysis. The proposed method is not only suitable for SBR equipment, but is also suitable for other Industrial devices. The experimental results performed on a lab-scale SBR plant show a good equip-ment-management performance.

• Journal of Korean Society of Forest Science
• /
• v.85 no.2
• /
• pp.316-324
• /
• 1996

This study was conducted by relative time study to identify the allowance time and basic work time, which is together composed of the total work time, in the wage composition and work process composition. This study was done for the case of a basic one person a group from thinning treatment for some conifer species such as Japanese red pine, Japanese larch, pitch pine and Korean pine. 1. In order to apply the Japanese allowance time of four species to the general conifer case, the maximum value of allowance time composition value among those of four species was selected. The results are as follows: delay time for person 1.8%, rest time 14.1%, delay time for machine 12.5% and wating time 0.4%. The some of ratios of adjustment allowance time is 28.8%. 2. Estimated wage basis time table, which can be used for wage table or process table, was prepared by adding up adjusted general allowance time and standard work time estimated by estimation equation for each species through the time study.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.213-213
• /
• 2016

현재 반도체 산업에서는 디바이스의 고 집적화, 고 수율을 목적으로 패턴의 미세화 및 웨이퍼의 대면적화와 같은 이슈가 크게 부각되고 있다. 다중 패터닝(multiple patterning) 기술을 통하여 고 집적 패턴을 구현이 가능해졌으며, 이와 같은 상황에서 각 패턴의 임계치수(critical dimension) 변화는 패턴의 위치 및 품질에 큰 영향을 끼치기 때문에 포토마스크의 임계치수 균일도(critical dimension uniformity, CDU)가 제작 공정에서 주요 파라미터로 인식되고 있다. 반도체 광 리소그래피 공정에서 크롬(Cr) 박막은 사용되는 포토 마스크의 재료로 널리 사용되고 있으며, 이러한 포토마스크는 fused silica, chrome, PR의 박막 층으로 이루어져 있다. 포토마스크의 패턴은 플라즈마 식각 장비를 이용하여 형성하게 되므로, 식각 공정의 플라즈마 균일도를 계측하고 관리 하는 것은 공정 결과물 관리에 필수적이며 전체 반도체 공정 수율에도 큰 영향을 미친다. 흔히, 포토마스크 임계치수는 플라즈마 공정에서의 라디칼 농도 및 식각 선택비에 의해 크게 영향을 받는 것으로 알려져 왔다. 본 연구에서는 Cr 포토마스크 에칭 공정에서의 Cl2/O2 공정 플라즈마에 대해 O2 가스 주입량에 따른 식각 선택비(etch selectivity) 변화를 계측하여 선택비 제어를 통한 Cr 포토마스크 임계치수 균일도 향상을 실험적으로 입증하였다. 연구에서 사용한 플라즈마 계측 방법인 발광분광법(OES)과 optical actinometry의 적합성을 확인하기 위해서 Cl2 가스 주입량에 따른 actinometer 기체(Ar)에 대한 atomic Cl 농도비를 계측하였고, actinometry 이론에 근거하여 linear regression error 1.9%을 보였다. 다음으로, O2 가스 주입비에 따른 Cr 및 PR의 식각률(etch rate)을 계측함으로써 식각 선택비(etch selectivity)의 변화율이 적은 O2 가스 농도 범위(8-14%)를 확인하였고, 이 구간에서 임계치수 균일도가 가장 좋을 것으로 예상할 수 있었다. (그림 1) 또한, spatially resolvable optical emission spectrometer(SROES)를 사용하여 플라즈마 챔버 내부의 O atom 및 Cl radical의 공간 농도 분포를 확인하였다. 포토마스크의 임계치수 균일도(CDU)는 챔버 내부의 식각 선택비의 변화율에 강하게 영향을 받을 것으로 예상하였고, 이를 입증하기 위해 각각 다른 O2 농도 환경에서 포토마스크 임계치수 값을 확인하였다. (표1) O2 11%에서 측정된 임계치수 균일도는 1.3nm, 그 외의 O2 가스 주입량에 대해서는 임계치수 균일도 ~1.7nm의 범위를 보이며, 이는 25% 임계치수 균일도 향상을 의미함을 보인다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.6
• /
• pp.861-868
• /
• 2022

A key use of applying building information modeling (BIM) to the construction stage of a project is to help identify construction obstacles and to visualize construction status according to the progress of the construction schedule. When employing 4D simulation for this purpose, start and finish dates for each activity and a 3D model of the activity must be prepared. In this work, in order to simplify the configuration of a 4D model, minimum attribute information of the BIM model produced in the design stage was used to construct a system that generated activity information in the construction stage using a clustering algorithm. Its usefulness as actual schedule management information was then analyzed.