• 펄프종이기술
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• 제39권2호
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• pp.1-8
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• 2007

To examine the feasibility of dry forming technology for papermaking, a dry forming mold (DFM) was developed and evaluated. Main fanning section of DFM was a cylindrical tube, and at the top of the mold a stirring equipment was placed to disperse dry fibers. These fibers were screened using a hole type screen plate placed just under the stirring equipment and dropped freely on the fanning wire located 0.9 m below of the screen plate to form a dry fiber pad. The vertical and horizontal velocity of air flow in the forming cylinder were evaluated and analyzed to find the most effective method of air flow control in the cylinder. Humidification and pressing conditions to obtain a decent dry fanned papers were examined. Results showed dry fanned papers can be prepared with this dry forming mold. And this mold can be used to examine the effect of the papermaking process factors including pressing pressure, drying temperature, humidification on sheet quality of dry formed papers.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.1-8
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• 2002

The flow and combustion patterns have been investigated inside the gasoline engine cylinder with the swirl or tumble flow, whereas the air flow characteristics, which are generated in the part of intake system before entering into the intake manifold, have not been known completely. It is necessary to analyze the flow field in the intake system consisting of air rater, throttle valve and intake manifold. The throttle valve, used to control the intake air flow rate, is important because it makes various mass flow rate and flow patterns. Three-dimen-sional How characteristics such as velocities, turbulent intensities and Reynolds shear stresses are measured by the hot wire anemometer at the exit of the throttle valve with the variation in the valve opening angle($15^{\circ}$, $45^{\circ}$, $75^{\circ}$ and $90^{\circ}$) and the Reynolds numbers (45000, 70000 and 140000). There are a lot of changes in flow characteristics at $75^{\circ}$ due to the large recirculation flow comparing with those of the other cases, and the streamwise velocity is especially enforced strongly below the valve shaft. The other component velocities are relatively large near the centerline parallel to the valve shaft. The effects of the Reynolds number on the flow field are not severe.

• Corrosion Science and Technology
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• 제7권5호
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• pp.265-268
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• 2008

Prestressed Concrete Cylinder Pipe(PCCP) had became one of the dominating kinds of pipes substituting for steel pipes because of its unique feature (high intensity, high pressure and high leakproofness). PCCP was produced firstly by Bonna company in France. By the end of 20th century, there were over 19000 km of this product installed in America. PCCP was introduced from Ameron company by Shandong Eletric Power Pipeline Engineering Company in 1988. As the statistical data in 2002, 700 km of PCCP had been applied in China, and the application trended towards rapid increase.Since prestressing wire would be corroded in environment, Several accidents due to the breakdown of pipe had happened. Consequently the external wall of pipe should be covered with protective coatings. There was a lack of technical study in corrosion and control of PCCP, because PCCP had been applied for a short time in China. in order to ensure the service life of PCCP, we have developed a kind of protective coating for concrete pipe, which had high intensity and anti-corrosive property with convenient applicability. The physical and chemical properties, painting technology and field application of this coating was introduced in the paper, at the same time, the future of external protective coating for PCCP was looked into.

• 한국컴퓨터정보학회논문지
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• 제8권1호
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• pp.13-19
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• 2003

유연 생산 시스템(FMS)이나 자동화 창고(AWS) 등에 이용되는 AGV(Automated Guided Vehicle)에 관하여 많은 연구가 진행 중이다. 기존의 AGV는 마그넷 테이프나 전기와이어, RF나 Laser를 가이드라인으로 사용하고 있어 가이드라인 설치와 변경 시 시간과 비용이 많이 드는 단점이 있다. 본 논문에서는 단일 컬러 CCD카메라를 가지고 50mm 황색 컬러테이프를 가이드라인으로 사용하여 주행하는 AGV를 구현하였다. 컬러테이프를 사용하므로 라인설치 및 변경 추가 시 작업 시간이 빠르고 비용이 적게 드는 장점이 있다. 구현한 AGV의 구조와 컬러 특성만을 추출하여 주행용 가이드라인을 탐색하는 영상처리 기법과 AGV주행 결과를 제시하였다.

• 한국컴퓨터정보학회논문지
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• 제8권2호
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• pp.1-7
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• 2003

본 연구는 영상처리에 의한 문자인식에 관한 연구로써 기존의 AGV(Automated Guided Vehicle)가 가이드라인으로 사용하는 마그넷테이프나 전기와이어 등을 사용하지 않고 칼라테이프를 가이드라인으로 사용하였다. AGV는 주어진 경로를 따라 주행하는 것과 목적지를 판별할 수 있는 마크나 숫자 등 표식을 인식하여 정지 동작을 하는 것이 중요하다. 본 논문에서는 AGV가 정지할 때 사용되는 마크는 자동차 번호판과 같은 폰트, 같은 크기의 청색숫자를 사용하였다 복도 환경에서 황색 주행라인과 청색의 숫자 마크를 설치하고 Color 특성만을 추출하여 라인을 탐색하여 주행하면서 DP패턴 매칭으로 숫자를 100％ 인식하여 일시적으로 정지하는 영상처리 기법과 AGV주행결과를 제시하였다.

• 한국연초학회지
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• 제15권2호
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• pp.167-173
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• 1993

Pirimiphos - methyl was fogged in a tobacco warehouse to determine the proper dose rate, Small wire cages, containing adults and larvae of cigarette beetle (Lasiodema senicorne F.) were put at different altitude in the warehouse of which the holding capacity was about 250m3. At recommended dose rate, 0.4ml/m3(25% ai), it brought about 100% mortality of adults and 98.8% -100% mortality of larvae. When the dose rate was reduced to about half the recommended one, 97.6 and 96.4% mortality could still be obtained against adults and larvae, respectively. The number of the beetles monitored by sex - pheromone trap was greatly reduced after the fogging in the warehouses at 4 geographic places in Korea. When the warehouses were ventilated for one hour immediately after the fogging done for 48 hours, workers could not detected any opposing smell in the warehouses. And panel members responded positively that there was no negative effect on the taste of the cigarettes made of the fogged tobacco. Although the residue of the chemical was detected from the cigarettes in 4 of 5 cases, the residue was 1.1-1.3$\mu\textrm{g}$/20 cigarettes except for one case from which 3.3$\mu\textrm{g}$/20 cigarettes residue was detected. The relatively low residue is about l/450-1/150 of the WHO/FAO tolerant level.

• 한국보건간호학회지
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• 제13권1호
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• pp.12-24
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• 1999

In Korea. the investigation were related of health promotion is actively expanded Since 1990. We analysed the characteristics of the theses for an academic degree. relate to lifestyle of health promotion. have published since 1980. According to age group. analysing causal factors affection the health-promotion and will sugesting for health promotion program strateges. The results were summarized as follows: 1. Health promoting caocept is related to health locus of control. self respect. perceived health status. self ifficacy and gender role. 2. Among health promoting lifestyle. emotional support, self-realizationhygienic lifestyle were significantly positive. and the older. the lesser health-promoting complicnce. 3. Causal factors affecting the health-promoting lifestyle were identified health promoting behaviors wire affected by demographic factors which were gender. age. marrige status. education level. relision. vocation. job satisfaction. economic status and by social support factors which were familiarity. family function personal relationship. gender role. 4. In school age. daily lifestyle behaviors were significantly positive. middle and high schllo age froup were affected by stress. nutrition. social support. self-realization were causal factors explaining health promoting behavior of middle age and old age but. there was problems of exercise behaviors. therefore. the need to develop a health education program for the all age group to improve the health-promoting lifestyle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.467-471
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• 2004

The development of a tilting train with construction of electric line on the conventional railway is required for speed-up on the conventional railway with many curving sections. For development of tilting train, the study and development of the tilting system and tilting bogie having the different mechanism with a general high speed train will play a main role for improving the technology in the field of Korean railway. The study and development of the pantograph tilting mechanism in order to keep a good contact behavior between a pantograph and a contact wire by tilting a pantograph on the opposite direction of the vehicle tilting direction. In this study, we analyzed the aerodynamic characteristic of a developing pantograph on the tilting train and obtained the contact force with catenary by aerodynamic lift force by the aerodynamic analysis. We also performed the numerical analysis for design the device controlling lift force on a pantograph. From the aerodynamic simulation and parameter study for a device to control the lift force, we will suggest the various shape and the optimal shape of it corresponding to a developing tilting pantograph. The Fluent software is used for the calculation of flow profile in this study.

• 산업기술연구
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• 제27권A호
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• pp.103-110
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• 2007

Concrete is a material that will crack during its service life by its very nature. For bridge decks this is especially significant as these cracks allow accelerated ingress of chlorides and the subsequent corrosion of the reinforcing steel and deck deterioration. Very-early strength latex-modified concrete (below ; VES-LMC) was developed in order to realize early-opening-to-traffic bridge deck concrete. Although there has been little research to document the degree of cracking in VES-LMC overlay, there has been a general perception among highway agencies that overlay cracking of VES-LMC, particularly early-age cracking, is a one of problems which should be solved. The purpose of this study was to analyze the cause of map, transverse and longitudinal cracking in VES-LMC and to provide a control methods for minimizing the occurrence of cracks. The proposed prevention against map and transverse cracking was verified by field applications. VES cement was modified, the unit cement contents was reduced into $360kg/m^3$ from $390kg/m^3$, the maximum size of coarse aggregate was increase into 19mm from 13mm, wire mesh and steel fibers were incorporated in concrete mixture.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.338-343
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• 2001

Recently the steel parts used at automobiles are required to be used under high stress more than ever before in need of the weight down. To achieve this requirement of a high strength steel, it must be necessary to decrease inclusion content and surface defect as like decarburization, surface roughness etc., In this study, the surface conditions are measured to know the influence on fatigue properties by two cases of shot peening of two-stage shot peening and single-stage shot peening. And for this study, two kinds of spring steel(SAE 9254, DIN 50CrV4) are made. This study shows the outstanding improvement of fatigue properties at the case of two-stage shot peening in the rotary bending fatigue test and this is assumed to be from (1) on low stress condition, the single stage shot peening is not affected by nonmetallic inclusion under metal. (2) it is possible that the two-stage shot peening increases the fatigue life and the high stress, but, that is affected by nonmetallic inclusion under metal. (3) so far, beeasily 50CrV4 have made high stress. But, results also show fatigue failures originated at inclusion near surface, and this inclusion type is turned out to be a alumina of high hardness.