• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.685-691
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• 2013

A load-cell-type anemovane operates based on wind vector properties. The developed load-cell-type anemovane is of a fixed type in which the wing does not rotate, unlike in the case of existing anemovanes. The load-cell-type anemovane is required to accurately derive the correlation between the load ratio and the wind direction in order to develop a qualified product. This is because the load ratio repeats every $90^{\circ}$ owing to the use of four load cells, and its value varies nonlinearly according to the wind direction. In this study, we compared analytical results with experimental results. Fluid analysis was carried out using ANSYS CFX. Furthermore, the prototype was tested using a self-manufactured wind tunnel. The wind direction was selected as the design variable. 13 selected wind direction conditions ranging from $0^{\circ}$ to $90^{\circ}$ with an interval of $7.5^{\circ}$ for analysis were defined. Furthermore, 10 wind direction conditions with an interval of $10^{\circ}$ for the experiment were defined. We derived the relations between the pressure ratio and the wind direction through the experiment and fluid analysis.

• Journal of the Korean Vacuum Society
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• v.12 no.3
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• pp.151-156
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• 2003

Two capacitance diaphragm gauges(CDG) and two resonance silicon gauges(RSG) were calibrated using an ultrasonic interferometer as a national low vacuum standard in KRISS. The CDG has superior pressure resolution and is rugged as well as resistant to over-pressure because of all-metal inner components. Meanwhile, the RSG is a new type of MEMS sensor that has excellent calibration stability and is resistant to mechanical shocks. The calibration uncertainties were analyzed according to the ISO procedures. Results showed that the maximum difference of the expanded uncertainties was $9\times10^{-3}$Pa at the generated pressure of 100 Pa for the two different types. It is remarkable that the RSG can be used as a transfer standard at low vacuum since their accuracies were found to be within 0.5 %.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.766-773
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• 2021

Chemicals, such as ammunition, are disposable items that cannot be reused because of their operational characteristics. The reliability of the test process and test results are important factors in evaluating the performance of guns and ammunition. The pressure after firing is a crucial value in an acceptance test of guns and ammunition performance; hence, accurate measurements are required. The pressure in the artillery is measured using the copper crusher gauge. The compression amount of copper is converted into a pressure by either a length-pressure conversion table or conversion formula. Therefore, the exact measurement of the squeeze of the copper crusher is related directly to the correct estimate of the pressure. Currently, the pressure is measured manually by the operator, which always includes some human error. In this study, the cause of the measurement error was analyzed, and the automatic measuring system for copper crusher deformation was developed to minimize the error elements. A copper crusher could be measured using the probe sensor and CCD camera, and the Jig for stable positioning was also designed. A designated SW was also developed for the system operating and measurement-analysis. This measuring system through this study may be used for an ammunition stockpile reliability test and gun/ammunition acceptance test.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.128-128
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• 2001

제지기술의 변화속도가 빨라지고 제품의 고품질화가 요구가 많아지면서 finishing 공정 에 대한 관심과 중요성이 점점 더 높아지고 있다. 소비자의 요구에 부합되는 제품의 품 질을 얻기 위해서 여러 가지 방법들이 개발되고 있으며, 그 중에서 calender 설비 및 처리 기술이 계속적으로 발전하고 있는 추세이다. 특히 coated paper 제조 공정에서의 s supercalender 처 리 기 술은 매 우 중요하다. F Finishing 공정은 종이의 품질을 결정하는 제지 공정의 마지막 단계로서 calendering 처리 방법에 따라 제품의 품질을 크게 변화시킬 수 있다. 따라서 본 연구에서는 기존의 s supercalendering 처리 조건을 변경시켜 도공지의 품질 특성을 관찰하였으며 실험실용 s supercalender와 현장 적용을 통하여 supercalender 처리 조건이 도공지 품질에 미치는 영향에 대하여 검토하고 이를 이용하여 제품 품질을 개선시키기 위해서 수행하였다. 안료 배합비를 달리하여 다양한 온도와 압력 조건을 적용하여 보았으며 동일한 백지광 택을 갖는 여러 조건들에 대해서 각각의 품질 특성을 살펴보았다. 동일 백지광택에서 온도가 높을수록 macro-roughness, micro-roughness는 더 우수하게 나타났으며 이는 printability의 차이로 이어 졌다. 실험실용 supercalender를 이용한 실험에서 경도가 다른 두 가지 탄성롤로 cotton roll 과 polymer roll을 사용하였으며 통일한 온도와 압력 조건에서 calendering 특성은 서 로 다르게 나타났다. Calendering 조건이 가혹할수록 두 roll간의 특성은 더욱 두드러지 게 나타났으며 macro-roughness 보다는 micro-roughness에서 차이가 더 큰 것으로 확인되었다. 이러한 두 roll간의 특성 차이로 인하여 실제 인쇄 결과는 다르게 나타날 것으로 예상된다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.13-22
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• 2002

This paper presents characteristics of CrOx thin-film Strain gauge pressure sensors, which were deposited on SUS630 diaphragm by DC reactive magnetron sputtering in an argon-Oxide atmosphere(Ar-(10%)$O_2$). The optimized condition of CrOx thin-film strain gauges were thicknessrange of 2500$\AA$ and annealing condition ($350^{\circ}C$, 3 hr) in Ar-10 %$O_2$deposition atmosphere. Under optimum conditions, the CrOx thin-films for strain gauge is obtained a high resistivity, $\rho$=156.7$\mu$$\Omega$cm, a low temperature coefficiect of resistance, TCR=-86 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal, 15. The output sensitivity of pressure sensor obtained is 2.46㎷/V and the maximum non-linearity is 0.3%FS and hysteresis is less than 0.2%FS. The output characteristics of pressure transmitter obtained is 4~20㎃ and total accuracy is less than $\pm$0.5%FS. In those conclusions, CrOx thin film pressure sensors is quite satisfactory for many applications in industrial electronics.

• International Commerce and Information Review
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• v.13 no.4
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• pp.411-433
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• 2011

This article investigates the impacts of firms' regulatory compliance and voluntary innovation activities in environmental management on the development of their organizational capabilities and the enhancement of their performance, within the Korean context. The study invokes a structural equation analysis. The results indicate that voluntary innovation activity in response to market pressures makes a significant contribution to the development of firm-specific organizational capability and the enhancement of firms' performance, but regulatory compliance activity does not significantly affect either organizational capability or performance. This capability was also seen to have implications for firm's performance. This article also suggests several policy implications related to the research.

• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.102-115
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• 2012

The purpose of this paper is to review several different methods calculating gas hydrate saturations. There are three methods using downhole log data, core data (including pressure core), and seismic velocity data. Archie's equation using electrical resistivity of downhole log data is widely used for saturation calculation. In this case, Archie's parameters should be defined accurately. And the occurrence types of gas hydrate significantly affect to saturation calculation. Thus saturation calculation should be carefully conducted. The methods using chlorinity and pressure core data are directly calculated from core sample. So far, the saturation calculated from pressure core gives accurate and quantitative values. But this method is needed much more time and cost. Thus acquisition of the continuous data with sediment depth is realistically hard. The recent several results show that the saturation calculated from resistivity data is the highest values, while the value calculated from pressure core is the lowest. But this trend is not always absolutely. Thus, to estimate accurate gas hydrate saturation, the values calculated from several methods should be compared.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.67-72
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• 2019

The purpose of this study was to analyze the effects of computer game usage time on trunk muscle thickness and pressure pain threshold. The 33 study participants were divided into Group A, which spent less than 10 hours per week playing computer games; Group B, which spent between 10 and 20 hours per week playing computer games; and Group C, which spent more than 20 hours per a week playing computer games. The thickness of the participants' upper trapezius (UT), pectoralis minor (PM), anterior scalene (AS), and middle scalene (MS) muscles as well as the pressure pain threshold of their UT, PM, AS, MS, and levator scapular (LS) were measured. The study found that the PM, AS, and MS muscle thickness in group C was significantly greater than in the other groups (p<.05), and the UT, AS, PM, and LS pressure pain threshold in group C was significantly lower than in other groups (p<.05). Therefore, those who use computers for a long period of time during the week should recognize that their computer usage may cause musculoskeletal disorders.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.50-59
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• 1999

The effect of a variant drain orifice damping on the characteristics of a servovalve flapper-nozzle stage is analyzed. Steady-state characteristics of flapper-nozzle stage and the linearized dynamics of flapper-nozzle assembly with a spool valve show that the variant drain orifice damping could improve such null performance characteristics as null pressure sensitivity and linearity of gain function. Generalized design criterion and a sufficient condition for servovalve stability are also established.

• Journal of the KSME
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• v.18 no.4
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• pp.13-19
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• 1978

산업계에서 용접의 역할은 근년에 와서 그 중요성이 날로 더해 가고 있다. 산업계의 발전과 동승 해서 용접이 차지하는 비중이 확대되고 여러 분야에서 금속을 결합하는 수단으로 응용되고 있는 것은 이미 알고 있는 것으로 매일매일 용접기술은 개발이 되여 현재 사용되고 있는 용접법만 하 더라도 30여종이나 된다고 하며 금속합금은 이 용접법에 의해서 만족하게 처리되고 있다고 보겠 다. 여기서 생각해 보고 싶은 것은 어떤 금속합금을 용접하여 접합할 때 여러가지 용접법중에서 어떤 방법을 어떻게 채용된 용접법의 장단점을 충분히 고려한 후에 용접작업에 들어가지 않으면 안된다. 그런데 비교적 역사가 짧은 원자력공업은 재료를 접합하는데 여러가지로 어려운 문제점 을 제공하고 있는데 이것은 비단원자력공업 뿐만이 아니고 사람들이 금속을 처음으로 만들기 시 작했을 때부터라고 생각이 든다. 이 산업의 발전은 용접기술자가 여러가지로 복잡한 문제를 어떻 게 빨리 안전하게 해결할 수 있느냐에 달려 있다고 본다. 그러므로 용접기술자는 신기한 특성을 가지고 있는 금속의 접합기술을 개발하지 않으면 안되겠지만 원자력공업에서 적용되는 아주 높은 온도에서도, 높은 압력에서도 견딜 수가 있고 중성자 충격에도 손상을 받지 않는 성질이 요구된 다. 또 실험장치등도 운전중에는 방사성이 강하기 때문에 용접의 완전성이 절실히 요구된다.