• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.1875-1878
• /
• 2005

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with electron beam gun head unit is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included ceramic isolation plate and main body which are essentially constructed for electron beam gun head unit are designed and manufactured. And this electron beam gun head unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• 소성∙가공
• /
• 제14권6호
• /
• pp.565-569
• /
• 2005

Reactor Vessel is one of the most important structural parts of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings have been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the open die forging process and manufacturing experience of large head forgings which can be used for the reactor vessel of 1,000MW nuclear power plant.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 제10회 단조 심포지엄
• /
• pp.131-139
• /
• 2005

Reactor Vessel is one of the most important structural part of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings has been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the development trend of the open die forging process and manufacturing experience of large head forgings which canl be used for the reactor vessel of nuclear power plant.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 춘계학술대회 논문집
• /
• pp.397-400
• /
• 2005

Reactor Vessel is one of the most important structural part of nuclear power plant. It is manufactured by various steel forgings such as shell, head and transition ring. Head forgings has been made by open die forging process. After steel melting and ingot making, open die forging has been carried out to get a good quality which means high soundness and homogeniety of the steel forgings by using high capacity hydraulic press. This paper introduced the open die forging process and manufacturing experience of large head forgings which cant be used for the reactor vessel of 1,000MW nuclear power plant.

• 한국정밀공학회지
• /
• 제8권3호
• /
• pp.18-26
• /
• 1991

A study on the measuring and evaluation of LSC(Least Square Center) roundness was carried out. The experimental set-up was made by index head and indicator, and the measuring data were compensated by a developed computer program. The results obtained are as follows : 1) An index head can conveniently be used to measure LSC roundness. 2) A program for calculating LSC roundness is developed. 3) Without a high quality roundnes measuring apparatus, LSC roundness can be measured and calculated by using index head and the developed program in machine shop as well as in a measuring room

• 대한두경부종양학회지
• /
• 제11권2호
• /
• pp.167-172
• /
• 1995

Pharyngocutaneous fistula(PCF) is one of the complications following total laryngectomy in laryngeal and hypopharyngeal cancer. Fistula lead to delayed wound healing, more serious complications such as carotid blow-out, prolonged hospitalization, significant patient morbidity and occasional mortality. Identification of patients at high risk for fistula formation, appropriate preventive measures, and appropriate management are the head and neck surgeon's responsibility. So we analyzed the clinical data of pharyngocutaneous fistula which was developed after total laryngectomy. Following results were obtained: 1) Occurrence of PCF increases with salvage surgery compared to curative surgery. 2) Early detection and effective management of PCF are the key factors to decreasing the hospitalization period. 3) Constructing a pharyngostoma seems to be an ideal method of preventing dangerous complications and ultimately closing the fistula. 4) Simultaneous reconstruction is necessary in the high risk group.

• 한국안전학회지
• /
• 제16권2호
• /
• pp.13-21
• /
• 2001

The effect of water spray for the fire sprinkler depends on droples distribution over maximum possible floor area. The present study are carried out for the characteristics of water spray and droplets experimentally and numerically km two fire sprinkler heads which are CHM head and CHl heal CHl head is self-production and CHl head is widely used up to date. As the result of using CHM head, water spray and droplets are distributed over large area because CHM head has smooth surface and non-flamed shape. When the pressure of fire sprinkler head is low, SMD(sauter mean diameter) is large and when the pressure of fire sprinkler head is high, SMD is small.

• 한국운동역학회지
• /
• 제15권3호
• /
• pp.153-159
• /
• 2005

The purpose of this study was to investigate the Effective X-Factor in golf swing. The term X-Factor means the relative rotation of shoulders with respect to hips during the golf swing. To ascertain the Effective X-Factor that resulted in a high club head speed at impact six golfers' swing motions were videotaped and analyzed using three-dimensional techniques. The results can be summarized as follows. The standard deviations of the professionals' average club head speeds were higher than the amateurs'. This means that the professionals' swing skills were better than amateurs' in driving accuracy and consistency. As the club head speeds were increased gradually the X-Factors and the club head speeds had reached to the subjects' average club head speeds, but the X-Factors and the club head speeds were not increased above the subjects' average club head speeds. The X-Factor Stretch early in the down swing was existed and Professional stretched values were higher than the amateurs. In conclusion my research results suggested that the increase in Effective X-Factors had no relationship to the increase in club head speeds.

• 대한인간공학회지
• /
• 제15권1호
• /
• pp.69-78
• /
• 1996

Current fighter pilots, flying new generation aircrafts with high performance, are under severe stress during aerial combat maneuvering when they are exposed to high sustained +Gz(Head-to-foot) acceleration stress. Two major factor limiting performance during high sustaied +Gz acceleration stress are loss of vision-greyout or blackout, and loss of consciousness (LOC). These symptoms are believed to occur as a result of insuff- icient blood flow to the retina and the brain. This study was conducted to evaluate the effects of high sustained +Gz stress under different seat back angle. The results. obtained by the biodvanmic computer simulations using the ATB(articulated total body) model, are represented with respect to three variables, such as HIC(head injury criterion) value, average G, and maximum G. The results demonstrate that the seat back angle(over $30^{\circ}C$) had a significant effect to decrease +Gz stress on the head segment and had no significant effect on HIC.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 1995년도 추계연구발표회 논문개요집
• /
• pp.82-83
• /
• 1995