• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.536-539
• /
• 2000

A simple and effective method has been developed for the immobilization of the cell on polyurethane foam. Two types of commercially available polyurethane foam and Hydro-filt were tested. The ultimate purpose of the process is to produce low-cost materials for hydrogen sulfide removal which are being increasingly used for industrial application. Effect of several parameters were studied on the cell loading. These parameters were type, size, and amount of polyurethane foam. MC-70 was the best immobilization material of three type of carriers, and optical particle size was $5{\sim}8mm$ and amount of polyurethane foam was 8g/L.

• Journal of electromagnetic engineering and science
• /
• 제7권3호
• /
• pp.134-137
• /
• 2007

This paper presents the design of the compact UHF Bandpass filter of CT-type with a novel mixed coupling topology. In further detail, this new coupling structure mathematically equals the transmission zero that enables particularly the better rejection performance in the stopband without increasing the filter's order. To envision this design concept, we fabricated a microstrip filter whose measurement proves to agree with the predicted performance and the suggested coupling structure reduces the overall size, and will be possibly used in the miniaturized UHF apparatus such as the RFID system.

• 한국유체기계학회 논문집
• /
• 제8권5호
• /
• pp.7-12
• /
• 2005

Experimental study was conducted to increase the oxygen transfer efficiency of air diffusers in clean water. By measuring the bubble size from the bubbly two-phase flow visualization with several air diffusers, the size of air bubbles near the top surface of aeration tank seems to be independent on the diffuser types. Considering design parameters for the better break-up of larger bubbles around the air diffusers, advanced conceptual air diffusers using nozzle-type throat showing the higher oxygen transfer efficiencies were made.

• 건축역사연구
• /
• 제22권1호
• /
• pp.7-14
• /
• 2013

Because of the demographic and economic changes and the lifestyle diversification, the new housing types such as the Quasi-housing and urban small-size multi-unit housing are appeared in korea. The current housing use classifications are regulated in accordance with the housing divided ownership, horizontal and vertical size of housing, and the number of units. However, there is a limit to accommodate the new housing type. Therefore, this study proposed the direction of improvement of the housing use classifications through comparative analysis of foreign housing use classifications. Also, building regulations are applied according to the building use classifications. Therefore, the new housing types in building act are very urgent and important. So this study is derived the problems of the current housing use classifications and is proposed the improvement direction of it through the expert opinion survey.

• 한국전기전자재료학회논문지
• /
• 제16권12호
• /
• pp.1097-1102
• /
• 2003

In this paper, we used only PR as etching mask, while it used usually Cr/AU as etching mask, and in order to fabricate a photosensor has the increased sensitivity, we investigated on the sensitivity of general type and p-i-n type diode. we designed microchannel size width max 10um, min 5um depth max 10um, reservoir size max 100um, min 2mm. Fabrication of microfluidic devices in glass substrate by glass wet etching methods and glass to glass fusion bonding. The p-i-n diode has higher sensitivity than photodiode, Considering these results, we fabricated p-i-n diodes on the high resistive(4㏀$.$cm) wafer into rectangle and finger pattern and compared internal resistance of each pattern. The internal resistance of pin diode can be decreased by the application of finger pattern has parallel resistance structure from 571Ω to 393Ω.

• 한국직업건강간호학회지
• /
• 제27권2호
• /
• pp.131-138
• /
• 2018

Purpose: The purpose of this study was to examine the differences in requirement and activity related to workers' health promotion according to business type and enterprise size. Methods: This study is a secondary analysis of data extracted from a survey on the Enterprise Health Promotion Index. For the present analysis, 7,784 companies were selected. Results: Requirements for lifestyle management and activities to prevent musculoskeletal disorders were the highest. The requirement and activity of musculoskeletal disorders and cerebrovascular disease were high in the manufacturing industry. Meanwhile, in the non-manufacturing industry, the requirement and activity of job stress management were high. Small-sized companies had a high requirement to prevent musculoskeletal disorders and cerebrovascular disease. Conclusion: Government support should be strengthened in workers' lifestyle management. Additionally, workers' health promotion in small-sized companies needs to focus on preventing musculoskeletal disorders and cerebrovascular disease.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집A
• /
• pp.278-285
• /
• 2001

Aluminum/Aramid Fiber Reinforced Plastic(Al/AFRP) laminates are applied to the fuselage-wing intersection. The main objective of this study was to evaluate the delamination zone behavior of Al/AFRP with a saw-cut and circular hole using average stress criterion and the effect of notch geometry. Mechanical tests were carried out to determine the cyclic-bending moment and delamination zone observed ultrasonic C-scan pictures. In case of Al/AFRP containing saw-cut specimen, the shape and size of the delamination zone formed along the fatigue crack. However, in case of Al/AFRP containing circular hole specimen, the shape and size of delamination zone formed two types. first type, delamination zone formed along the fatigue crack. Second type, not observed fatigue crack. Therefore, delamination zone was formed dependently of the circular hole shape.

• 설비공학논문집
• /
• 제9권3호
• /
• pp.323-332
• /
• 1997

It was reported by some researchers that two-stage parallel-plate ESPs, commonly called electronic air cleaners, show decreasing behavior of collection efficiency as particle size decreases below about $0.03{\mu}m$. This phenomenon is attributed to partial particle charging characteristics, where some of incoming particles are not charged in the charging cell of 2-stage parallel-plate ESP. One way to improve the decreasing collection efficieny in that particle size range is to enforce particle charging quantity in the charging cell. In the present study, in order to do this a 2-wire series-type charging cell modified from a 1-wire normal-type one was suggested and investigated theoretically and experimentally concerning improvement of the collection efficiency. It was confirmed from the experimental and theoretical works that the collection efficiency was apparently improved.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 춘계학술대회논문집
• /
• pp.416-420
• /
• 2004

Recently, the importance of vibration reduction at the local structure such as tank, deck which attached machinery and compass deck, has continuously increased by owner and shipbuilder. Because crews are afflicted with them and severe vibration problems affect on the crack of structure. This study conducted optimum design to get a stiffener size of local structure to reducing the vibration level and dec leasing the weight of structure in ship. Random tabu search method (R-Tabu) has fast converging time and can search variables size domains for nonlinear problems. This paper used Nastran external call type independence optimization method which makes using a solver module from Nastran.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.169-172
• /
• 1999

Thixoforming process has been accepted as a new method for fabricating near net shaped products with lighweight aluminum alloys. The thixoforming process consists of reheating process of billet, billet handing filling into the die cavity and solidification of thixoformed part,. in this paper the thixoforming experiments are performed with two different die temperature ({{{{ TAU _d}}}}=20$0^{\circ}C$ 30$0^{\circ}C$) and orifice gate type. The microstructures of SSM(357, A490 and ALTHIX 86S) fabricated in thixoforming process are evaluated in therms of globularization and grain size. effect of alloying elements onthe surface and internal defects is investigated. Finally the methods to obtain the thixoformed products with good mechanical propertis are proposed by solution for avoiding the surface and internal defects.