• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.408-417
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• 2000

The design and simulation of meshing of a single enveloping worm-gear drive with modified surfaces is presented. Generally worm-gear is generated by the hob which is identical to the worm. This process guarantees the conjugation between the worm and the gear but results in a line contact at every instant which is very sensitive to misalignment. The localization of bearing contact is necessary to reduce the sensitivity of the worm-gear drive to misalignment. Practically this localization is achieved by application of an oversized worm type hob to cut the worm-gear. The oversized hob approach is very practical and effective to localize bearing contact but can not provide the conjugation between the worm and the modified worm-gear. This work proposes an analytical procedure to make the worm surface conjugate to the worm-gear which is cut by the oversized hob. The developed computer program allows the investigation of the influence of misalignment on the shift of the bearing contact and the determination of the transmission errors, the contact ratio and the principle curvatures. The developed approach has been applied for ZK type of single-enveloping worm-gear drives and the developed theory is illustrated with a numerical example.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.672-674
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• 2001

Axial magnetic field(AMF) type electrode can increase the interrupting capability of vacuum interrupters. But, this interrupting capability vary with design parameters such as shape of electrode, slits of contact, material of contact and so on. In this paper, shown arc characteristics of unipolar axial magnetic field type electrode for vacuum interrupter by design parameters such as shape of contact slits and diameter of contact. And, confirmed vacuum arc configuration by individual design parameter using high speed camera.

• 대한가정학회지
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• 제27권3호
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• pp.1-11
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• 1989

The purpose of this study is to evaluate the effect of self-actulization and demographic variables upon the selection of clothes among adult women. The Results of this research can be sumerized as follows; 1. Marital status has direct effect on the self-actualizing values, Marital status and houshold type have direct effect on the inner directed and self-regard traits. Marital status and monthly income have direct effect on a capacity for intimate contact. 2. Self-actualizing values and inner directed traits are directly related with individuality of clothing. Frequency of contact with massmedia, household type and employment have direct effect on the individuality of clothing. 3. Self-regard, self-actualizing values, school career and houshold type have direct effect on the conformity of clothing. 4. Self-actualizing values, capacity for intimate contact and frequency of contact with massmedia have direct effect on the fashionability of clothing.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.163-172
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• 2000

주성과 반성의 온도차가 큰 $(\mid\bigtriangleup T\mid\geq1,000K)$ EB형 접촉식쌍성에 WD 모웰의 모드 3을 적용 할 경우, 주성과 반성의 표면 반사율 (A), 주변감광계수 (x) 그리고 중력강광계수 (g)가 각각 서로 같은 값을 갖는 일반적인 경우와 각각 서로 다른 값을 갖도록 수정된 모드 3의 경우를 비교 분석하였다. EB형 접촉식쌍성인 DO Cas, GO Cyg 그리고 FS Lup에 적용한 결과, 수정된 모드 3에 의해 얻은 이론적인 광도곡선이 관측된 광도곡선을 더 잘 만족하고 있음을 확인하였다.

• 센서학회지
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• 제22권5호
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• pp.369-373
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• 2013

In this paper, we developed contact type temperature sensor with single crystal silicon strip thermopile. This sensor consists of 15 p-type single crystal silicon strips, 17 n-types and contact electrodes on silicon dioxide silicon membrane. The result of electromotive force measuring showed very good characteristic as $15.18mV/^{\circ}C$ when temperature difference between the two ends of the thermopile occurs by applying thermal contact on the thermopile which was fabricated with silicon strip of $200{\mu}m$ length, $20{\mu}m$ width, $1{\mu}m$ thickness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.540-543
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• 2003

This paper presents design and manufacture of RF type non-contact radiological dosage measuring device. It also concerns on the broad out-line and the ways of improvement about RF type non-contact radiation measuring device. Measuring radiological dosage with non-contact RF, the stability and efficiency of the measure have been improved by reforming constant current circuit. Furthermore, applying communication protocol in process makes it possible to achieve faster and more accurate communication than old circuit. On the base of those, RF type non-contact radiological dosage measuring device which consists of radiological dosage measuring module and Reader module has been designed and manufactured. While testing communication against embodied device, the possibility of the field application could be confirmed.

• Journal of Welding and Joining
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• 제22권1호
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• pp.43-49
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• 2004

Contact tip is located so near to welding arc that it is heated to high temperature during long time welding. In such a situation, tip changes in its microstructure and in turn its mechanical properties. This study was intended to investigate those changes by using simulated heat treatment. As a result of this study, it was confirmed that tip of Cu-P alloy hardened with severe cold deformation lose its initial hardness to a large extent within 60 min due to the occurrence of rapid recrystallization while that of Cu-Cr composition hardened by proper aging treatment can preserve its intial hardness for about 1,000 min or longer. Based on these results, suggested was a guideline that can classify contact tips into two different grades: deformation-hardened type and precipitation-hardened type. Following a guideline, a tip with Cu-Cr composition can be classified into the deformation-hardened type if it is in the over-aged condition. Such a guideline is well described.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.610-614
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• 1996

Sealing of lubricat-air mixture in the high performance machining conte is one of most the important characteristics to carry out enhanced lubrication. High speed spindle requires non-contact type of sealing mechanism. Evaluating an optimum seal design to minimize leakage is concerned in the aspect of flow control. Effect of geometry and leakage path are evaluated according to variation of sealing geometry, Velocity, pressure, turbulence intensity of profile is calculated to fina more efficient geometry and variables. This offers a methodological way of enhancement seal design for high speed spindle. The working fluid is regarded as two phases that are mixed flow of oil phase and air phase. It is more reasonable to simulate an oil jet or oil mist type high speed spindle lubrication. Turbulence and compressible flow model are used to evaluate a flow characteristic, This paper arranges a geometry of mostly used non-contact type seal and analyzes leakage characteristics to minimize a leakage on the same sealing area.

• 한국전기전자재료학회논문지
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• 제19권9호
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• pp.825-831
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• 2006

As an increase of chip complexity and level of chip integration, chip input/output (I/O) pad pitches are also drastically reduced. With arrival of high complexity SoC (System on Chip) and SiP (System in Package) products, conventional horizontal type probe card showed its limitation on probing density for wafer level test. To enhance probing density, we proposed new vertical type probe card that has the $70{\mu}m$ probe needle with tungsten wire in $80{\mu}m$ micro-drilled hole in ceramic board. To minimize alignment error, micro-drilling conditions are optimized and epoxy-hardening conditions are also optimized to minimize planarity changes. To apply wafer level test for target devices (T5365 256M SDRAM), designed probe card was characterized by probe needle tension for test, contact resistance measurement, leakage current measurement and the planarity test. Compare to conventional probe card with minimum pitch of $50{\sim}125{\mu}m\;and\;2\;{\Omega}$ of average contact resistance, designed probe card showed only $22{\mu}$ of minimum pitch and $1.5{\Omega}$ of average contact resistance. And also, with the nature of vertical probing style, it showed comparably small contact scratch and it can be applied to bumping type chip test.

• 한국자동차공학회논문집
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• 제21권2호
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• pp.55-62
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• 2013

An analytical procedure to determine a proper profile of the spring rail that generates intended contact pressure distribution in the flat wiper blade is introduced. The flat wiper blade is one piece blade and subjected to pressing force at a center point. In this type of blade, contact pressure distribution in the tip of rubber strip is determined by the pressing force, the initial profile of the blade before contact and bending stiffness of the blade. Experimentally obtained bending stiffness of the blade assembly is almost identical to that of the spring rail. Principle of reciprocity has been used to define the initial profile of spring rail from the deformed profile that is assumed to be identical to the windshield glass profile. The procedure has been verified experimentally by measuring the contact pressure of the blade assembled with the spring rail designed by the procedure proposed here. Measured contact pressure distributions of the blades show good agreements with intended distributions over the entire blade span. Consequently, it can be concluded that proposed procedure has relatively good accuracy in developing the spring rail for flat blade having a specific contact pressure distribution.