• 한국염색가공학회지
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• 제29권2호
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• pp.86-96
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• 2017

To make uniform pressure distributed over the contact surface was necessary to cold pad batch dyeing machine. In this study, to confirm characteristic of flexibility and the contact pressure distribution through experimental analysis of padder roll were controlled by hydraulic cell. When there were no load pressure only inner pressure, the value of displacement in the center of padder were greater than the end of the padder. The results of this study showed that the padder had the optimum value of inner pressure for uniform contact pressure distribution. Measuring the contact pressure in a padder system were driven by using a pre-scale film. Uniform contact pressure distribution of cell padder were a linearly with load pressure and inner pressure. When the load pressure was less than 8 tons, the inner pressure for the uniform contact pressure was 1~4 bar. The padder roll performance curves proposed in this study were available for practical production environments and various roll designs.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 추계학술대회논문집
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• pp.149-152
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• 1999

The effect of initial orientation on the microstructure and texture evolution of two ferritic stainless steels was investigated. the columnar and equiaxed crystal specimens which were prepared from continuous casting slab were hot rolled annealed cold rolled and annealed respectively. The rolling and recrystallization textures at each process stage were examined by orientation distribution function (ODF) and electron back-scattered diffraction (EBSD); The observation showed that the orientation density of the $\alpha$-fibre of hot rolled band of columnar crystal specimen was more pronounced than that of the equaxed one at the center layer. Nevertheless the cold rolled textures of Type 430 steel have demonstrated a rather similar development . Compared to Type 430 steel the development of the $\alpha$-fibre in the center layer of Type 409L steel was much more pronounced. The relation between texture evolution and ridging behaviour has been discussed.

• 소성∙가공
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• 제8권6호
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• pp.612-619
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• 1999

Internal and external defects of an inner pulley for automobile air conditioner are investigated in this study. Inner pulley is a part of compressor clutch assembly of automobile air conditioner. In cold forging of inner pulley, the design requirement are to keep the same height of the inner rib and outer one and to make uniform distribution of hardness in the forged product. At the end of the forging of inner pulley, the piping defect as an external defect begins to form at the back center of the billet. The internal crack as an internal defect also occur at the adiabatic shear band which usually has maximum ductile fracture value. It is important to predict when the internal and external defects occur during the deformation process, in order to minimize the amount of discard that is generated. The finite element simulations are applied to analyze the defects. The validity of the computational results are examined by experiments. These computational results are in good agreement with the experimental ones.

• Journal of Dairy Science and Biotechnology
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• 제17권1호
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• pp.32-38
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• 1999

Korean dairy industry is placed on the very critical situation with the progress of free trade marketing system internationally. To keep and improve the dairy food market, better measures are imperative for dairy industry. Especially, the milk distribution system is premodern to some extent, in comparison with both the production and the processing part of dairy industry. Reform measures for the promotion of domestic milk consumption by lowering the distribution cost are as follows. First, out-sourcing of the logistics department can decrease the circulation cost of milk. Secondly, milk should be packed into large-size package(more than 1 liter) to save both package and distribution cost. Thirdly, milk should be distributed from plant to consumers through the hygienic distribution system including perfect cold chain system, Above reform measures can not come true through the efforts taken by one company but through co-worker, concerted research, and joint in-vestment among dairy companies that can reduce the distribution cost and provide consumers with the best service, eventually resulting in the increment of milk consumption.

• 현장농수산연구지
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• 제14권1호
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• pp.23-45
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• 2012

본 연구는 고랭지배추의 생산·유통체계에 대한 문제점을 분석하고 개선과제를 제시하는 데에 목적이 있다. 이를위해 고랭지배추를 생산하는 생산자, 산지유통인, 도매시장 종사자, 대형마트 구매담당자에 대한 심층적인 인터뷰를 통해 유용한 정보들을 수집하여 분석하였고 또한 고랭지배추 주산지의 생산과 도매시장의 유통체계 현황에 대한 자료들을 분석하여 고랭지배추의 생산·유통체계에 대한 매우 유용한 시사점을 얻을 수 있었다. 결론적으로 고랭지배추의 생산·유통체계에 대한 현황분석을 통해 개선방안들이 제시되었는 데 첫째는 고랭지배추 비가림재배 방법의 도입을 통해 생산의 안정성을 도모하고, 둘째는 고랭지배추 유통정보에 대한 투명성을 제고시키며, 셋째는 고랭지배추의 주산지로부터 소비자에 이르기까지의 물류체계 개선을 위해 단계적으로 콜드체인시스템을 구축하는 방안을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• Tribology and Lubricants
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• 제36권6호
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• pp.385-390
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• 2020

It rains heavily, such as long rain and typhoons, during a typical rainy season in Korea. In this season, several fuel contamination accidents by water and vehicular problems caused by water contaminated fuel occur. Many research groups have studied the effects of water contaminated fuel on vehicles and environment. However the characteristics of water contaminated fuel have not been studied. In this study, we prepared diesel samples with a constant ratio of water (0~30 volume %) using an emulsifier. Then, we analyzed these diesel samples for their representative fuel properties. In the analytical results, diesel with 30% water showed an increase in fuel properties such as density (823→883 kg/㎥), kinematic viscosity (2.601→6.345 ㎟/s), flash point (47→56℃), pour point (-22→2℃), CFPP (cold filter plugging point) (-17→20℃) and copper corrosion number (1a→2a). The low temperature characteristics, such as low pour point and CFPP, blocks the fuel filter in the cold season. In addition, water contaminated diesel decreases lubricity (190→410 ㎛) under high frequency reciprocating rig (HFRR) and derived cetane number (54.81→34.25). The low lubricity of fuel causes vehicle problem such as pump and injector damage owing to severe friction. In addition, the low cetane diesel fuel increases exhaust gases such as NOx and particulate matters (PM) owing to incomplete combustion. This study can be used to identify the problems caused by water contamination to vehicle and fuel facilities.

• 한국농림기상학회지
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• 제14권4호
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• pp.277-282
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• 2012

냉기호 지대 안에서도 일정 수준의 바람이 부는 장소에서는 일 최저기온이 기존 공간기후모형에 의해 예측된 만큼 떨어지지 않음이 관찰되었다. 경남 하동군 악양 집수역 출구부근의 실측자료를 토대로 냉기호가 형성된 25일에 대하여 기존 방법에 의한 일 최저기온 예측 시 발생하는 추정오차를 그 때 관측된 풍속과 비교한 결과 바람이 강해질수록 추정오차가 커지는 경향이 뚜렷해서 풍속이 2m/s에 이르면 냉기호 효과가 완전히 소멸되는 것으로 나타났다. 풍속과 추정오차 간 관계는 Y=2X+0.4 ($R^2$=0.76)로 표현되며 이 식에서 Y는 추정오차($^{\circ}C$), X는 풍속(m/s)이다. 이 식을 기존 일 최저기온 추정모형의 냉기집적효과에 결합하여 악양 집수역 냉기호 수몰지역에 위치한 3곳의 일 최저기온 추정에 이용하였다. 이때 입력 풍속은 바람장 모형 구동에 의한 모의풍속이었다. 추정된 일 최저기온은 오차의 평균평방근(RMSE)이 기존 모형의 1.72에서 1.20으로 줄어들고, 평균오차(ME)로 표현한 편기성(bias)도 -1.33에서 -0.37로 개선되었다.

• 대한핵의학회지
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• 제18권1호
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• pp.25-31
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• 1984

The effeciency of combined application of isotope scan and ultrasonography of thyroid was assessed in 91 patients with thyroid nodule. Malignancy rates were 35.5%, 18.8%, & 0% in solid, complex & cystic nodule group, respectively. No statistically significant co-relationship was found between isotope scan finding & ultrasonographic finding. Malignant nodules were found only in cold solid nodule group & cold complex nodule group, and rate of malignant nodule was different between them(45.8% in cold solid nodule group & 20.7% in cold complex nodule group). Difference between the rate of cystic change in benign & malignant nodule observed in our study(59.2% vs. 35.3%) was thought to explain at least partly the statistically different rate of malignant nodule in cold solid nodule & cold complex nodule group. No difference in the boundary condition, echogenicity & distribution of internal echo existed between benign nodule group &malignant nodule group.

• 한국정밀공학회지
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• 제13권5호
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• pp.67-73
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• 1996

The necessity for more accurate automatic flatness control(AFC) system has increased of customers' requirement for cold rolled steel sheet. Therefore, many cold rolling mills replaced its AFC system with a measuring roll of the contact type form the non-contact type. In this paper. The performance of AFC system of contact type has been investigated under industrial conditions. It has two kinds of actuator: roll bender, spot cooling system. The test results are as follows: The more strip thickness is thick, the smaller the I value, and the more it is thin, the bigger the I value. And a complex distribution of strip tension was controlled, for example, not only a pocket wave but also a simple center wave and edge wave. Because the tension deviation is larger at acceler- ation speed and decelerationspeed than steady speed, AFC system of contact type is better to adopt over 50m/mim. AFC system reduces rapidly large flatness deviation. The maximum I value of strip has been decreased to 13 I, and sticker, defects caused by poor flatness, have been decreased about 60%.