• 한국수산과학회지
• /
• 제12권1호
• /
• pp.13-18
• /
• 1979

Volumetric efficiency is a determining factor for tile measurement of compessor capacity, but it is practically hard to take an accurate measurement of capacity characteritics so that most of users trust the data of makers catalogue. We often realized the discrepancy in their data with actual capacity. This study was attemped to establish the basic data of capacity characteristics of compressor by measuring volumetric efficiency of high speed multi-cylinder compressor and rotary compressor. The volumetric efficiency was calculated based on the quantity of the flow of ammonia vapor and pressure difference in suction state of orifice plate and compressor. The volumetric efficiency of high speed multi-cylinder compressor was $37-61\%$ and that of rotary compressor was $57-82\%$ when compression ratio was in the range of 4-12. The discrepancy in volumetric efficiency at an equal evaporating temperature between the makers catalogue and the measured data was $5.5\%$.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
• /
• pp.652-656
• /
• 2002

The HDM(Hole Drilling Method) is a relatively simple and accurate method in measuring residual stress of welded metal. Various methods of evaluating residual stress are studied in welding field. The method of cutting holes on the plate much affects the accuracy of result. Especially for the hard material like stainless steel difficult to cut preciously is difficult to measure residual stress on welded metal. Because heat conduction of stainless steel is lower than other general steel, the magnitude of residual stress might be different as to changing of welding conditions. Therefore, The distribution of residual stress on the STS304 steel after welding using HDM is evaluated in this paper.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.199-202
• /
• 2003

Ultraviolet-nanoimprint lithography (UV-NIL) is a promising method for cost-effectively defining nanoscale structures at room temperature and low pressure. Since the resolution of nanostructures depends strongly upon that of nanostamps, the nanostamp fabrication technology is a key technology to UV-NIL. In this paper, a 5$\times$5$\times$0.09 in. quartz stamp whose critical dimension is 377 nm was fabricated using the etch process in which a Cr film was employed as a hard mask for transferring nanostructures onto the quartz plate. To effectively apply tile fabricated 5-in. stamp to UV-NIL on a 4-in. Si wafer, we have proposed a new UV-NIL process using a multi-dispensing method as a way to supply resist on a wafer Experiments have shown that the multi-dispensing method can enable UV-NIL rising a large-area stamp.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.857-864
• /
• 2006

Due to the difficulties in numerical generation of random fields that satisfy not only the probabilistic distribution but the spectral characteristics as well. it is relatively hard to find an exact response variability of a structural response with a specific random field which has its features in the spatial and spectral domains. In this study. focusing on the fact that the random field assumes a constant over the domain under consideration when the correlation distance tends to infinity, a semi-theoretical solution of response variability is proposed for in-plane and plate bending structures. In this procedure, the probability density function is used directly resulting in a semi-exact solution for the random field in the state of random variable. It is particularly noteworthy that the proposed methodology provides response variability for virtually any type of probability density functions.

• Journal of Welding and Joining
• /
• 제19권6호
• /
• pp.664-670
• /
• 2001

The HDM(Hole Drilling Method) is a relatively simple and accurate methods in measuring residual stress of weldment. Various method of evaluating residual stress are studied in welding field. The method of cutting holes on the plate much affects the accuracy of result. Especially for the hard material like stainless which is difficult to cut preciously is difficult to measure residual stress of weldment. Because heat conduction of strainless steel is lower than other general steel, the magnitude of residual stress might be different as to changing of welding conditions. Therefore, the distribution of residual stress on the STS304 steel after welding using HDM is evaluated in this paper.

• 대한기계학회논문집B
• /
• 제25권9호
• /
• pp.1149-1156
• /
• 2001

The objective of the present study is to investigate the performance of electronic scale mitigation unit(ESMU), which reduces the amount of scale in a heat exchanger. The circular tube with diameter of 19mm and plate-and-frame heat exchangers with 20 thermal plates were used for the tests. In order to accelerate the rate of scale in a laboratory test, artificial hard water of 1000ppm(as CaCO$_3$) was recirculated at a flow rate of 5 lpm, 7 lpm, and 9 lpm throughout the tests. The effect of ESMU on the scale thickness and overall heat transfer coefficients was examined. The test results showed that the ESMU could reduce the scale deposits even in the acceleated test.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 추계학술대회논문집
• /
• pp.751-755
• /
• 2003

In this paper, floor impact noise reduction in a steel structure is studied. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7. In addition, floor SBN(Structure-borne Noise) and floor damping are measured to study the effect of floating floor. structure. It is shown that VL(Visco-elastic Layer) is more effective when hard plates are added above the VL.

• 대한조선학회논문집
• /
• 제41권5호
• /
• pp.41-47
• /
• 2004

In this paper, floor impact noise reduction in cruise ship cabin is studied. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7. In addition, floor SBN (Structure-borne Noise) and floor damping are measured to study the effect of floating floor structure. It is shown that VL(Visco-elastic Layer) is more effective when hard plates are added above the VL.

• Animal Systematics, Evolution and Diversity
• /
• 제34권1호
• /
• pp.64-68
• /
• 2018

The genus Callochiton Gray, 1847 is small to medium sized chiton (up to $55{\times}36mm$ in size) and includes approximately 30 species worldwide, most of which are found on hard substrata in subtidal zone. To date, only three species of Callochiton Gray, 1847 have been reported in Japan. In this study, we found C. foveolatus(Is. Taki, 1938) as first record of the family Callochitonidae Plate, 1901 in Korea and its morphological features were described and compared with other northwestern Pacific species. In addition, the partial fragment of mitochondrial DNA cytochrome c oxidase subunit I sequences of C. foveolatus was determined as DNA barcoding record and compared with other congeneric species.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제49권11호
• /
• pp.632-636
• /
• 2000

Fuzzy controllers show good performance in case of the systems being nonlinear and difficult to solve. But these fuzzy controllers have problems which have to decide suitable rules and membership functions. In general, we decide those using the heuristic methods or the experience of experts. Recently, G.A. have been studied in this field. The number of rules increase exponentially when the number of input and output increase. It also makes hard to decide the rules and membership functions even though we use G.A. In this paper, we suggest parallel fuzzy controllers, and also the method to decrease the number of rules. The excellent performance of these methods is confirmed through simulations.