• Korean Journal of Medicinal Crop Science
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• v.12 no.3
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• pp.209-213
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• 2004

Ligusticum chuanxiong is receiving much attentions as one of the important medicinal crops with the increasement of the crude drug demands. This study was conducted to obtain the basic informations of breeding of Ligusticum chuanxiong. Embryological characteristics were examined to elucidate the process of male and female gametophytic development and fertilization. Meiosis and nucleus division of megaspore and microspore were proceeded normally. With regard to the formation of female gametophyte, only a half of female gametophyte developed to normal egg apparatus. While another 50% showed abnormal egg apparatus with poly-nuclei or non-nuclei ovule. The pollens developed from the micros pore were formed more than 90 % of normal pollen. It was difficult to observe fertilization because ovule tissue was very compact and cell was extremely tiny, but could be easely observed proembryo and embryo formation. Only 30 percent developed into proembryo and subsequently into embryo, and the others were degenerated.

• Journal of Acupuncture Research
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• v.28 no.1
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• pp.15-28
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• 2011

Objectives : To understand the strength and weakness of traditional warm needle acupuncture based on existing research outcomes in Korea mostly and to suggest how to build the desirable warm needle acupuncture apparatus by overcoming demerits of traditional and currently existing ones. Methods : We searched warm needle relating papers in Korean with the key words of '온침, 화침, 열자극' by using DBpia, Journal of Korean Oriental Medical Society, Journal of Korean Acupuncture & Moxibustion Society and Journal of Society for Meridian and Acupoint. Degree dissertations in Korean were also searched with the same words through the search engine of Library of Kyung Hee University. We also searched with words of 'warm, thermal, heat, needle, acupuncture, temperature' via Pubmed and found a small number of English written papers and large number of Chinese written ones. To find english translated version of those papers, we googled with the same words with no success. Results : About 20 papers on warm needle acupuncture written in Korean were found and analyzed with respect to experimental factors that affected the thermal properties or the amount of heat stimulus of the acupuncture. More rigorous descriptions seemed to be required on the insertion depth, duration and manipulation of warm needle treatment. A basic heat transfer model was presented for the clarification of heat loss through the needle of warm needle acupuncture. Environmental factors such as air flow on the properties seems to be considered for the warm needle acupuncture. Conclusions : Papers on warm needle acupuncture were reviewed and analyzed based on their thermal properties and tools such as needles and moxa cones. Several suggestions were made on the descriptions relating the properties. Necessary specifications were introduced to aim modernized warm needle systems.

• Journal of the Korean earth science society
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• v.31 no.1
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• pp.88-94
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• 2010

A simple laboratory device and methodology are developed for deep understanding of the western boundary current (WBC). The apparatus consists of a rotating (count-clockwise) rectangular tank with a sloping bottom in order to simulate the beta effect, the variation of the Coriolis parameter with latitude. We also used a clockwise rotating disk at the surface water to mimic the wind stress forcing in mid-latitude oceans. Four experiments were carried out using some combination of a bottom type and a rotation of the tank. Experiment with the beta effect clearly demonstrated the WBClike flow as well as the Sverdrup interior. However, the water in a tank gave rise to an inertial motion under the influence of a constant Coriolis force alone. We also discussed a stiffening of the rotating fluid on the basis of the Taylor-Proudman effect. We believe that the apparatus and methods developed in this study help to understand the WBC due to the beta effect.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.635-645
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• 2015

This study analyzed the range of motion of upper body in different configurations of firefighters' protective clothing and equipment. The purpose of this study was to understand the influence of firefighters' protective clothing and equipment over upper body motion in order to improve design of firefighters' protective clothing and equipment. 12 firefighters' upper body range of motion was analyzed while performing standing and walking trials in five different garment configurations including turnout ensemble, fire boots and the self-contained breathing apparatus. Analysis of upper body range of motion included spinal joints of L5S1, L4L3, T1C7, and C1Head. During standing trials, garment configurations caused a significant difference in range of motions at joints of L5S1, L4L3, T1C7, and C1Head. Analysis on the mean of range of motions at L5S1 and L4L3, showed that firefighters' waist bent forward significantly to a greater extent while they wore a self-contained breathing apparatus. A significantly increased range of motion was found for T1C7 and C1Head while carrying a self-contained breathing apparatus, which indicated an increase in the extension of the trunk and neck backward to stand upright and look squarely. A significant difference in range of motion was also found for L5S1 and L4L3 during walking trials.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.4
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• pp.29-45
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• 1991

Lip type stern tube sealing systems have used in almost all the middle or large ships which are being constructed in these days. It seems that the pressure fluctuation of the seal ring interspace, the cross-section profile and the materials quality of the seal rings have great effects on the sealing fuction of this sealing system. In this paper, the mechanical movement of lip seal ring which plays the most important role in stern tube sealing system and the possibility of leakage caused by pressure fluctuation are studied by theory and experiment. Using the finite element method for the axi-symetric object which receives the torsional load, the displacement and stress analysis of the seal rings, and also the possibility of crack occurance is checked by theoretical analysis. If the force which seal ring lip periphery receives is too small, there will be the possibility of leakage caused by the pressure fluctuation of the seal ring interspace, and if this force is too large, the frictional force between the seal ring and the liner will become problematical. The possibility of leakage caused by hardening of seal ring materials and creep phenomena of tested seal rings are also examined. The trial seal rings were designed and manufactured using the program of displacement and stress analysis developed in this study and the experimental apparatus to test the trial seal rings was also designed and manufactured. This trial seal rings were fitted in the experimental apparatus which was made in the same form as an actual stern tube. The one side of this apparatus was filled with sea water and the other side of it was filled with the lubricating oil. The leakage of oil and sea water was checked and the temperature was measured, rotating the propeller shaft at the constant velocity by D.C. motor. It was proved that the trial seal rings made in Viton rubber functioned excellenty but the trial seal rings made in N.B.R. rubber had problem in its durability.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.181-188
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• 2003

The objects of this study were to discuss the performance of its using magnetic compass and to do a trial manufacture of the apparatus generating artificial magnetic field of 3-axis type to assess the performance of compass using terrestrial magnetism in the various magnetic field. The results obtained were summarized as follows: The magnetic field of each axis showed the linearly increase in accordance with the increase of electrical current. Average range difference between measured and calculated values was 0.33∼1.93μT and there were no big difference. The magnitude and direction of magnetic field showed some change in the edge of Helmholtz coil, but it appeared to stabilize in the center. In the horizontal magnetic force of 0.30gauss and 0.40gauss, the measured and calculated values of the damping characteristic of magnetic compass showed a good agreement. However, the confidence level was low at the horizontal magnetic force of 0.50gauss.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.404-413
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• 1998

This study was conducted in order to clarify the factors affecting the number of utilization to health center for the shipyard workers who have been work in exposed environment to solvent. At first the tendencies of the number of utilization to health conte. in accordance with cumulative exposure(CE), lifetime weighted average exposure(LWAE), one's place of duty, work contents, states of using safety apparatus, the degree of the knowledge on handling solvents, exposure year. 1). The increase in the cumulative exposure(CE) war significantly higher in the number of utilization to health center. The group with longer exposure year showed significantly higher number of utilization to health center(p<0.01). Considering the work contents such as power blasting, spray, mixing and touch-up, the group of touch-up showed higher number of utilization to health center and this difference was statistically significant(p<0.001). Those who were not using the safety apparatus, showed higher number of utilization to health center, which was statistically significant(p<0.05). The degree of the knowledge on handling the solvent had no relation with using health center. 2) The results conducted from this study by multiple regression analysis in clarifying the factors affecting the number of utilization to health center, CE, exposure year and using safety apparatus was significant factor in utilization of health center.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.162-168
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• 2005

The lower flash points for the n-propanol+n-decane flammable mixture were measured by the Tag open-cup apparatus(ASTM D 1310). The experimental results of mixture exhibited the lower flash point than those of pure component in the flash point versus composition curve. The experimental value of the minimum flash point is $27^{\circ}C$ at a mole fraction of n-propanol of 0.71, and the flash point of n-propanol was $28^{\circ}C$. The experimentally obtained data were compared with the values that had been calculated by use of the prediction model, which assumes an ideal solution, and the flash point prediction models based on the van Laar equation were used to estimate the activity coefficients. The predictive curve based on an ideal solution deviated from the experimental data for this system. The experimental results demonstrate a close agreement with the predicted curves, which used the van Laar equation. The average absolute deviation(A.A.D.) from using the van Lau equation is $0.83^{\circ}C$. The methodology proposed here in this paper can thus be applied to incorporate an inherently safer design for chemical processes, such as determining safe storage and handling conditions for flammable solutions.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.1-6
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• 1997

In case of using the electrical apparatus in the hazardous atmosphere which exist flammable gas mixtures, There is a dangerosity of gas explosion accident by the electrical spark. The most general method to prevent the explosion by the spark is to use the flame-proof type electrical apparatus to isolate the ignition source. from the flammable atmosphere. But actualy it is impossible to isolate the ignition sources from the atmosphere. So it was needed to find the safe gap which prevent ignition of flammable atmosphere by transmission of flame or heat when a flammable gas mixture exploded inside the apparatus. In this study we tried to find the maximum experimental safe gap(MESG) of $H_2$-air, and $CH_4$-air mixtures by using the 8 litre spherical vessel with 25mm flange. The experiment parameter were ignition position, concentration and initial pressure before explosion. From the experiment the ignition position was affected to the MESG. MESG value was minimum near the stoichiometric concentration of gas mixtures, and according to the increase of initial pressure MESG was decreased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.304-306
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• 2007

In this paper, we presents a scheme for the parameter estimation and optimal control scheme for apparatus of container crane system. For parameter estimation, first, we construct the open loop of the container crane system and estimate its parameters based on input-output data, a real-coded genetic algorithm(RCGA) and the model adjustment technique. The RCGA plays an important role in parameter estimation as an adaptive mechanism. For controller design, state feedback gain matrix is searched by another RCGA and the estimated model. The performance of the proposed methods are demonstrated through a set of simulation and experiments of the experimental apparatus.