• 소성∙가공
• /
• 제9권6호
• /
• pp.615-623
• /
• 2000

The industrial application of hydroforming has a great potential in saying cost and achieving dimensional accuracy in automotive industry presently. The aim of the following article is to investigate the effect of process parameters on hydroformed part. Firstly, we have to investigate the change of mechanical properties for sheet and pipe material according to various radius/thickness ratio(r/t). The change of mechanical properties affects the yield stress more than the total elongation. Increase of yield stress for pipe has a bad influence on formability of hydroforming. Among the roll-forming process, the sizing process didn't change mechanical properties. The process parameters such as the initial pressure, mandrel shape and friction have seriously influenced on formability of hydroforming. Therefore we need to check formability of given material through the FE analysis in the beginning stage of process design and the predicted hydroforming process parameters ate generally a good starting point for the prototype tryout stage. The results of pretending, hydroforming analysis using FE model are good agreement with experimental results.

• 한국CDE학회논문집
• /
• 제7권4호
• /
• pp.254-261
• /
• 2002

Small marine propeller is generally machined by 5-axis machining. This paper suggests a method to create geometric model from point array data and 4-axis machining NC data for propeller. With conventional method, the setting posture should be changed, because propeller has front and back surface of wing. The change of setting posture has a bad influence on precision of propeller. So this paper pro-poses a method to machine propeller by single setup for 4-axis machining. The cutter moves to parallel direction of the XY plane. To determine the cutter orientation efficiently, the' tilting guiding line' is proposed. A proposed algorithm is written in C language and successfully applied to the 5-axis milling machine of industrial field.

• 대한가정학회지
• /
• 제23권2호
• /
• pp.13-19
• /
• 1985

While the appearance of new textiles and processing materials results in the improvement in quality of clothes and its luxury, a question about the irritation of clothes on the human body must be raised. In Japan and many countries in Europe, they are searching for a countermeasure against the bad influence of clothes on the human body for the purpose of protecting consumers. In our country, a little bit of study about the skin irritatio has been carried out. In this thesis, the literature on the kinds of the irritation of clothes on the human body was studied and analysed. And then I arranged it from the view-point of clothing hygienics. For example, we should observe the legal regulations and the administrative control in the process of production and distributive management of clothes for our safety. Therefore the authorities concerned must have preparations for the safety and this monograph is going to give information for it.

• 대한치과의사협회지
• /
• 제48권3호
• /
• pp.184-189
• /
• 2010

Snoring is a very common sleep disorder. Approximate 20~30 percent of population and 40~60 percent of middle and old age population are reported to have symptoms of snoring. Snoring patients do not frequently recognize snoring until spouse or colleague has noticed. Hence, for most people snoring has been not a serious health issue but one of bad sleeping habits. However, it recently draws social attention because most patients with diagnosed "Obstructive Sleep Apnea Syndrome" cased by obstruction of the upper airway are reported snoring. In this point, the author attempts to review the clinical aspects and treatments about snoring and "Obstructive Sleep Apnea Syndrome" in the medical and dental perspective.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 B
• /
• pp.754-757
• /
• 1995

This system can detect a ground fault point or a bad insulated line by measuring a power plant DC feeder insulation resistance at the uninterruptible power status. And when the power plant DC feeder with low frequency AC signal has a ground fault, this measuring system can keep recording of its ground fault current and phase checked by Z.C.T. Therefore the power plant could protect a unexpected service interruption.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2007년도 추계 학술논문 발표대회
• /
• pp.101-104
• /
• 2007

Currently most of underground structures in domestic apartment projects are being designed for parking lot and essential parking area is growing due to the increase in car-holding number per household. Moreover, most underground parking lots of today are combined with basement, therefore a pleasant environment in underground space is strongly needed for the dwellers' use. However, there always occur high percentage of humidity and surface condensation in underground parking lot because of the nature of underground structure and they are having a bad influence on the comfort and health of dwellers. Therfore, this study is planned to compare and examine the porformance and properties of currently used construction methods to prevent condensation and finally present the most suitable method.

• 복식
• /
• 제5권
• /
• pp.23-40
• /
• 1981

Jin Chung Sa is located Daeyoli, Jigogmyen, Saesangun, Choongchungnamdo, there are equipped a portrait scroll of Jung Chung Sin. And top of the town hill live in his 13th grandson, Jung Jong Sul. There are his portrait scroll and command flag and a suit of mail. According to say, remains was stollen at 1975 and it found again. But helmet thrown in the sea at the present time lceave only photo. Also, Chung Ryul Sa is located Anrakdong, Dongraegu, Pusan city, there are portrait scroll of died at the Dadaepo and Pusan Jin Sung and Dongrae Sung. Same memorial center is display mail of vice-envoy and inspector. Thus, this copy is refer to mail of Jung Chung Sin and Chung Ryul Sa, besides we will study mail production of Chung Ryul Sa possession. Even if they are bad to condition, I found court rank of mail through it. I hope, in the future, at that find a good data.

• 천문학회보
• /
• 제37권2호
• /
• pp.100.2-100.2
• /
• 2012

We performed near-IR imaging polarimetry of the $5{\times}9$ fields (${\sim}39^{\prime}{\times}69^{\prime}$) around 30 Doradus in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in the J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL in 2008 December and 2011 December. With the reliable LMC field data which were selected using a bad-data-rejection algorithm, we measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. We present physical relationship between the three bands using the photometric and the polarimetric properties of the sources.

• Nuclear Engineering and Technology
• /
• 제49권1호
• /
• pp.196-208
• /
• 2017

This study presents an experimental work in a petrochemical company for scanning a buried pipeline using $Tc^{99m}$ radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, $Tc^{99m}$ radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제6권2호
• /
• pp.117-122
• /
• 2002

From the beginning of the 20th century, calculus is gradually offered to high school students in many countries. However, in Chinese high school, the instruction on calculus is nearly an untouched field. Many people don't believe that high school students can study calculus well. They think calculus knowledge in students' brains is likely to become the “half-cooked food”, and this can produce a bad effect on the study of formal calculus at university. The authors consider that the emphasis of calculus in high school should be the intuitive understanding of fundamental calculus concepts, and it is also the basis of the understanding of formal concepts. Traditional mathematics course with chalk can't meet the needs of calculus teaching. The use of technologies can enhance the calculus teaching, especially the informal and visual calculus teaching, help students understand the underlying concepts. The authors describe how the use of technologies can improve the calculus teaching and learning, and point out that the use of technologies can clear up people's doubts.