• 한국정밀공학회지
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• 제31권8호
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• pp.743-747
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• 2014

In this study, drop-on-demand system using piezo-elecrtric inkjet printers was employed for preparation of collagen microspheres, and its application was made to the HepG2 cell-laden microsphere preparation. The collagen microspheres were injected into beaker filled with mineral oil and incubated in a water bath at $37^{\circ}C$ for 45 minutes to induce gelation of the collagen microsphere. The size of collagen microsphere was $100{\mu}m$ in diameter and $80{\mu}m$ in height showing spherical shape. HepG2 cells were encapsulated in the collagen microsphere. The cell-laden microspheres were inspected by the microscopic images. The encapsulation of cells may be beneficial for applications ranging from tissue engineering to cell-based diagnostic assays.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1017-1020
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• 2002

The pure Ti is taken annealing process for one hour at 90$0^{\circ}C$. The pure Ti is sufficient for ASTM B348 Grade2. The rolling mill roll the Ti-8Ta-3Nb(wt%) which became vacuum melting in arc furnace until the length is about 45mm and the thickness is about 6.05mm. Then it is made 6mm$\times$6mm$\times$44mm by wire cutting with EDM and it is made ∮ 6mm by rough cutting with the general purpose lathe. The machining accuracy of implant parts in the dental and medical science are decided by dimension, shpe, straightness, surface roughness. It is difficult to cut for the Ti alloy. It is caused problems of straight degree and surface roughness to the Ti alloy have many cases which length is smaller than diameter in cutting. Total 24 specimens different kind of 4 alloies are used in experiment to gain a cutting property. According to the cutting velocity, cutting depth, cutting temperature, feed and clearance angle experiments are performed. Conclusively it is expected that cutting depth of 0.5mm, feed velocity of 0.07mm/rev and cutting velocity of 80m/min could make a suitable result.

• Journal of Preventive Medicine and Public Health
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• 제27권4호
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• pp.777-791
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• 1994

For developing the Group Health Care System, health managers' job structure were analysed in the aspects of content, amount, and process. As a trial research, data were collected by a standardized job analysis table to 6 doctors, 40 nurses, and 11 industrial hygienists of Group Health Care System. Health care managers were performing complex and intellectual jobs such as healh education for workers, managing health care, conference as well as more simple jobs like as filling diary. Especially, job was consisted of general job and health care management job in the proportion of 1:2.18. The major general job were data management related with the health statistics, and major health care management jobs were managing health care, health counselling, environmental management of working sites. Each specific jobs were required differentiated intellectual capacity, creativity, autonomy, psychic stress, and physical work; most respondents perceived that health care management jobs should require more inputs than general jobs. Additionally job satisfaction and perceived need on specific Job items were anzlysed. Results of this research, suggested through the field experiences in working sites, should be considered for improving the Group Health Care System.

• Journal of Chest Surgery
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• 제24권11호
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• pp.1115-1124
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• 1991

Recently the thoracic injuries have been markedly increasing due to the vast increase of traffic accident, industrial disaster, and incidental accident as well as the frequent use of the murderous weapons including gun or rifle. Because the thoracic injuries could involve the heart, lung, and great vessels, and would influence the lives, prompt diagnosis and adequate treatment are essential. Most of thoracic injuries can be managed with the conservative treatment and simple surgical procedure such as closed thoracostomy, but certain cases require open thoracotomy to preserve lives and to return to their normal environment. The authors have analysed the result of 53 cases of open thoracotomy after thoracic injuries mainly according to the patient`s chart review. The mean age was 33.4 years old and male to female ratio was about 5: l. Injury mechanisms that elicited thoracic trauma indicated for open thoracotomy were penetrating[47%] and non-penetrating[53%] injuries. The Most common type of the thoracic lesion was hemothorax with or without pneumothorax and diaphragm rupture was the second. 58\ulcornero of thoracic injuries were accompanied by abdominal injuries and 47% by bone fractures. 34 patients were operated within 24 hours after injury and their average elapsed time was 13.6 hour. The remained patients were operated after 24 hours and their average elapsed time was 7.8 days. 71 cases of operative procedures containing some overlappings were performed: diaphragm repair[28], bleeding control[12], pulmonary and cardiac repair[4 cases] Postoperative complication rate was 32.1% and operative mortality rate was 9.4%[5/53].

• 한국정밀공학회지
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• 제15권12호
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• pp.212-219
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• 1998

During machining of dies and molds with sculptured surfaces. the cutter contact area changes continuously and results in cutting force variation. In order to implement cutting force prediction model into a CAM system, an effective and fast method is necessary. In this paper. a new method is proposed to predict mean cutting force. The cutter contact area in the spherical part of the cutter is obtained using Z-map, and expressed by the grids on the cutter plane orthogonal to the cutter axis. New empirical cutting parameters were defined to describe the cutting force in the spherical part of cutter. Before the mean cutting force calculation, the cutting force density in each grid is calculated and saved to force map on the cutter plane. The mean cutting force in an arbitrary cutter contact area can be easily calculated by summing up the cutting force density of the engaged grid of the force map. The proposed method was verifed through the slotting and slanted surface machining with various inclination angles. It was shown that the mean force can be calculated fast and effectively through the proposed method for any geometry including sculptured surfaces with cusp marks and holes.

• 한국환경보건학회지
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• 제44권5호
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• pp.433-443
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• 2018

Objectives: The purpose of this study was to examine the relationship between dietary habits and concentrations of urinary phthalate metabolite in elementary school children. Methods: This study was conducted in Seoul, South Korea. We collected urine samples from 156 children from a single school in September 2016. Information on dietary habits was obtained from the parents of the children. Five types of urinary phthalate metabolites were analyzed using a high-performance liquid chromatography tandem mass spectrometer. Multiple linear regression analysis was used to determine the factors affecting the concentrations of urinary phthalate metabolite. Results: Girls had a significantly lower concentration of urinary mono-n-butyl phthalate (MnBP) (p=0.006) than did boys. When the consumption of bean processed food and wrapped delivery food were more than once a week, urinary MnBP (p=0.021) and monobenzyl phthalate (MBzP) (p=0.032) concentrations were the highest, respectively. Conclusion: Several urinary phthalate metabolite concentrations were associated with demographic and dietary habits. Particularly, urinary MnBP and MBzP were associated with several processed foods. The findings of this study might be useful as basic data for establishing and educating on environmental health policy.

• 전기학회논문지
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• 제66권10호
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• pp.1445-1453
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• 2017

In this paper, we propose a fault detection model based on multi-layer neural network using data mining technique for faults due to boiler tube leakage in a thermal power plant. Major measurement data related to faults are analyzed using statistical methods. Based on the analysis results, the number of input data of the proposed fault detection model is simplified. Then, each input data is clustering with normal data and fault data by applying K-Means algorithm, which is one of the data mining techniques. fault data were trained by the neural network and tested fault detection for boiler tube leakage fault.

• 한국농촌건축학회논문집
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• 제15권4호
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• pp.59-68
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• 2013

This study aims to propose the future plan and research management of a beach and the relation between spatial structure of a village and layout of the beach focusing on Gimnyeong beach among the 12 general beaches in Jejudo. The results are as followings: First, Gimnyeong beach had the relation to primary industries of residents in the village in times past and was the space for everyday lives of residents. However, at present it has the relation to tertiary industries and is more important in community activities. Second, the entry part and the sandy beach of Gimnyeong beach were crucial in location and function in times past but total size of the beach has expanded for campground nowadays. Therefore, it is necessary to change the location of entry part to center part of the beach. In addition, convenient and safe facilities are need to be built more to corresponding to expanding area of the beach. Finally, in order to maintain clean sea, residents in the Gimnyeong have agreed to not make sea farms in the vicinity of Gimnyeong Beach which pollute the sea. Their roles have influenced on positive effect to community of the village, management of the beach, and maintenance of clean sea.

• 품질경영학회지
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• 제41권4호
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• pp.649-657
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• 2013

Purpose: In this study, the actual situation of domestic firms vulnerable to industrial security competence will be discussed. And accordingly be discussed for effective response measures. Methods: Using a structured questionnaire by mail, fax, e-mail and fill method was used respondents. By the end of '10 R&D Center, which holds 15,247 companies(population) among the 95% level of confidence, tolerance ${\pm}3%$ p-level corporate type, sector, region extraction method stratified multi-level companies were investigated through the final 1529. Results: The average level of industrial security capabilities 43.8%(out of 100) is very weak, so urgent and positive response measures also need to be investigated sought. Conclusion: we propose the effective management framework and improvement plans to prevent illegal industrial leakage are to be made.

• 자원환경지질
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• 제23권1호
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• pp.1-9
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• 1990

A couple of Au-Ag-bearing epithermal quartz veins of Cretaceous(87.9Ma) in age are developed in the Cretaceous(112Ma) granodiorite batholith which was emplaced in Mesozoic Baegyari sedimentary formation. Au minerals consist mostly of electrum with a 54.2-61.9 wt% Au and are closely associated with sulfide minerals including pyrite, chalcopyrite, pyrrhotite, galena and sphalerite. Homogenization temperatures of fluid inclusions in quartz, fluorite and calcite are $196-368^{\circ}C$ (avg. $240^{\circ}C$), $74-176^{\circ}C$ (avg. $115^{\circ}C$) and $75-200^{\circ}C$ (avg. $119^{\circ}C$) respectively. Sulfur isotopic compositions( +5- +8‰) of ore sulfides indicate a deep-seated sulfur origin. Oxygen isotope compositions of different stages of quartz vary from +5.6 to +9.3‰ and calculated ${\delta}^{18}O$ values of ore fluid at $250^{\circ}C$ range from -3.2 to +0.4‰, reflecting an isotopically evolved ore fluid mixed with a $^{18}O$ depleted meteoric water under the variable mixing ratios between hydrothermal and meteoric waters. Isotopic data of calcite minerals support the above conclusions.