• Korean Journal of Applied Biomechanics
• /
• v.12 no.1
• /
• pp.205-219
• /
• 2002

This research seeks to identify the plantar pressure distribution graph and change in force in connection with effective golf drive strokes and thus to help ordinary golfers have appropriate understanding on the moving of the center of weight and learn desirable drive swing movements. To this end, we conducted surveys on five excellent golfers to analyze the plantar pressure applied when performing golf drive strokes, and suggested dynamic variables quantitatively. 1) Our research presents the desire movements as follows. For the time change in connection with the whole movement, as a golfer raises the club head horizontally low above ground from the address to the top swing, he makes a semicircle using the left elbow joint and shaft and slowly turns his body, thus lengthening the time. And, as the golfer twists the right waist from the middle swing to the impact with the head taking address movement, and does a quick movement, thus shortening the time. 2) For the change in pressure distribution by phase, to strike a strong shot with his weight imposed from the middle swing to the impact, a golfer uses centrifugal force, fixes his left foot, and makes impact. This showed greater pressure distribution on the left sole than on the right sole. 3) For the force distribution graph by phase, the force in the sole from the address to halfway swing movements is distributed to the left foot with 46% and to the right foot with 54%. And, with the starting of down swing, as the weight shifts to the left foot, the force is distributed to the left sole with 58%. Thus, during the impact and follow through movements, it is desirable for a golfer to allow his left foot to take the weight with the right foot balancing the body. 4) The maximum pressure distribution and average of the maximum force in connection with the whole movement changed as the left (foot) and right (foot) supported opposing force, and the maximum pressure distribution also showed much greater on the left sole.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.9
• /
• pp.31-39
• /
• 2009

This paper shows prioritization process for equipment investment plans considering reliability indices and economical efficiency. To decide prioritization of distribution investment projects, we made a distribution system model using system configuration, it's component and load information and designed several investment alternatives to improve reliability of present system. Lastly, we proposed a evaluation model of economical efficiency assessment on distribution investment alternative projects. To analyze influence by reliability and economical efficiency, we produced economical effects with applying time-varying failure rate of KEPCO's main equipments of distribution system and interruption cost of electric power affected by investment. Finally, in order to insure the validity of this proposed methodology, we compared investment prioritization by economical evaluation with that of real investment alternatives of KEPCO's branch office. In conclusion, this paper shows what and how to interpret the reliability effects of distribution system investments into financial indicators beneficial for power utilities's managers to make decision on the perspective of corporate value.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.3
• /
• pp.111-119
• /
• 2014

Objectives This study aims to analyze a thermal distribution in biological living tissue during warm needling therapy by using a finite element method. The analysis provides an understanding of warm needling's efficacy and safety. Methods A model which consisted of four-layered tissue and stainless steel needle was adopted to analyze the thermal distribution in living tissue with a bioheat transfer analysis. The governing equation for the analysis was a Pennes' bioheat equation. A heat source characteristic of warm needling therapy was obtained by previous experimental measurements. The first analysis of the time-dependent temperature distribution was conducted through points on a boundary between the needle and the tissue. The second analysis was conducted to visualize the horizontal temperature distribution. Results When heat source's peak temperatures was above $500^{\circ}C$ and temperature rising rates were relatively slow, the peak temperature at skin surface exceeded a threshold of pain and tissue damage ($45^{\circ}C$), whereas when the peak temperature was around $400^{\circ}C$, the peak temperature at the skin surface was within a safe limit. In addition, the conduction of combustion energy from the moxa was limited to the skin layer around the needle. Conclusions The results suggest that the skin layer around the needle can be heated effectively by warm needling therapy, but it appears to have little effect at the deeper tissue. These findings enhance our understanding of the efficacy and the safety of the warm needling therapy.

• Journal of Energy Engineering
• /
• v.18 no.3
• /
• pp.147-155
• /
• 2009

Demand for distributed source by new and renewable energy has been gradually increasing recently. For the characteristics of distributed generation, distributed source is located near the distribution system and customers' buildings and can be operated in standalone mode or in interface mode with distribution system. When the distributed sources are interfaced with distribution system, the standard for interfacing distributed source with existing distribution system and operation manual should be updated with revisions in order to manage the distributed source effectively and operate the distribution system stably because how to operate the interfaced system is different from that of existing distribution system. In this paper, the FEP(Front End Processor) using the international standard protocol IEC-60870 for interfacing with distributed resources was designed. The designed system was verified via the test result using main control system for distributed generation and RTU(Remote Terminal Unit) for interface with distributed power generating.

• The Journal of Engineering Geology
• /
• v.24 no.3
• /
• pp.353-362
• /
• 2014

Pore structures in porous rock play an important role in hydraulic & mechanical behaviour of rock. Porosity, size distribution and orientation of pores represent the characteristics of pore structures of porous rock. While effective porosity can be measured easily by conventional experiment, pore size distribution is hard to be quantified due to the lack of corresponding experiment. We assessed pore size distribution of Berea sandstone using X-ray CT image based analysis combined with associated images processing, i.e., image filtering, binarization and skeletonization subsequently followed by the assessment of local thickness and star chord length. The aim of this study is to propose a new and effective way to evaluate pore structures of porous rock using X-ray CT based analysis for pore size distribution.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.38 no.1
• /
• pp.1-10
• /
• 2002

Biomass distribution of zooplankton showed its lowest level in June in the Cheju Strait, and the highest one was noticed in November when the secondary productivity is considered high. The highest biomass of zooplankton appeared in the sea areas of Sta. 14 and 11 respectively with relation to oceanographic conditions and wet weight of biomass. The positions were the center part of the Cheju Strait, while the sea area of the South Sea of Korea and the northern coast of Cheju Island showed relatively low biomass distribution. The characteristic of the sea area where biomass was densely distributed was it was in patch shape. Meanwhile, biomass distribution was higher in the northern sea area of Cheju Island than In the coastal sea of the South Sea of Korea. It shows formation of hairtail fishing grounds is closely related to biomass distribution in the Cheju Strait. In addition, high biomass is displayed in the center part of the saddle shaped ocean, a boundary of the heterogeneous water mass as a feature of fall oceanographic condition. Good fishing grounds of a hairtail In the Cheju Strait were formed outside of the sea area that showed patch-shaped high biomass distribution.

• Journal of KSNVE
• /
• v.6 no.3
• /
• pp.341-347
• /
• 1996

Vibration analysis is one of the most powerful tools available for the detection and isolation of incipient faults in mechanical systems. The methods of vibration analysis in use today and under continuous study are broad band vibration monitoring, time domain analysis, and frequency domain analysis. In recent years, great interest has been generated concerning the use of time- frequency repesentation and its application for a machinery diagnostics and condition monitoring system. The objective of the study described in this paper was to develop a new diagnostic tool for the rotating machinery. This paper introduces a new time frequency representation. Directional Winger-Ville Distribution, which analyese the time-frequency structure of the rotating machinery vibration.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.5 no.2
• /
• pp.212-225
• /
• 1995

This study was performed in a diatomite factory located at Pohang City, Kyeongsangbuk-Do. The major objectives were to evaluate sampling and analytical methods of diatomaceous earth dust. Concentrations of total and respirable diatomaceous earth dust were measured. Size distribution of dust was analyzed by a personal cascade impactor and the particle size analyzer which is an application of multiple diffraction method. Also crystalline silica in respirable and total dust samples was analyzed quantitatively by X-ray diffraction and Fourie Transform Infrared Spectroscopy(FTIR). The results were as follows: The airborne total and respirable dust concentrations, particle size distribution, and cristalline silica(quartz) concentrations showed approximately a log-normal distribution. The means of totaldust concentrations at flour maufacturing, fire brick grinding and packaging processes exceeded the Korean and American Conference of Governmental Industrial Hygienists standards, $10mg/m^3$. The size distribution of diatomaceous earth dust was log-normal and identified as the rspirable particle mass and thoracic particle mass. The crystalline silica in respirable and total dust samples was identified to quartz and contained about 10 % in those samples. Finally, it is necessary to study the applicability of multiple diffraction for particle size distribution to compare the ACGIH's size selective sampling with other materials containing crystalline silica. Also, advanced quantitative study to X-ray diffraction and FTIR methods shoud be carried out 10 verify general and specific characteristics for respirable crystalline silica.

• Journal of Distribution Research
• /
• v.11 no.1
• /
• pp.1-20
• /
• 2006

In these days of severe changes in the environment and economic slump, it is indispensable for firms to cope with the environment effectively. This study is an attempt to investigate the mechanisms through which output sector munificence and dynamism affect distribution channel performances, such as, satisfaction, trust, and commitment. Especially, this study focus on moderating effects on distribution channel integration that has not been investigated in the past. For the purpose of empirical testing, 70 corporate channels, 120 contractual channels, and 100 conventional marketing channels have been selected and analyzed. According to the result from moderated regression analysis, munificence strengthens distribution channel performances, while dynamism weakens them. And integration reinforces the effects.

• Korean Journal of Digital Imaging in Medicine
• /
• v.11 no.1
• /
• pp.5-13
• /
• 2009

There are several reasons to take X-ray in case of inpatients. Some of them who cannot ambulate or have any risk if move are taken portable X-ray at their wards. Usually, in this case, many other people-patients unneeded X-ray test, family, hospital workers etc-are indirectly exposed to X-ray by scatter ray. For that reason I try to be aware of free space scatter dose accurately and make the point at issue of portable X-ray better in this study. kVp dose meter is used for efficiency management of portable X-ray equipment. Mobile X-ray equipment, ionization chamber, electrometer, solid water phantom are used for measuring of free space scatter dose. First of all the same surroundings condition is made as taken real portable X-ray, inquired amount of X-ray both chest AP and abdomen AP most frequently examined and measured scatter ray distribution of two tests individually changing distance. In the result of measuring horizontal distribution with condition of chest AP it is found that the mAs is decreased as law of distance reverse square but no showed mAs change according to direction. Vertical distribution showed the mAs slightly higher than horizontal distribution but it isnt found out statistical characteristic. In abdomen AP, compare with chest AP, free space scatter dose is as higher as five-hundred times and horizontal, vertical distribution are quite similar to chest AP in result. In portable X-ray test, in order to reduce the secondary exposure by free space scatter dose first, cut down unnecessary portable order the second, set up the specific area at individual ward for the test the third, when moving to a ward for the X-ray test prepare a portable shielding screen. The last, expose about 2m apart from patients if unable to do above three ways.