• Journal of Preventive Medicine and Public Health
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• v.25 no.3 s.39
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• pp.269-286
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• 1992

The purpose of this study is to investigate the present state of worker's recognition and attitude about hazard materials and occupational disease in his workplace. In general worker's view of hazard materials and occupational disease that sis recognition and attitude is related to worker's health behavior for preventing occupational disease and improving his health status. The study subject is composed of workers in the asbestos related industry for example brake lining manufacturing industry, asbestos fiber manufacturing industry, and asbestos slate manufacturing industry. The result of the study are follows : 1. The most of workers in the asbestos related industry have taken health education and safety education, and the more than half of workers recognized the usefulness of preventive device, and ventilatory device in workplace. 2. About 70% of workers have always taken the preventive device. 3. About 80% of workers have recognized occupational disease in the asbestos related industry, and about 64% of workers have recognized that hls workplace have harmful effect on his health. 4. Recognition about the usefulness of ventilatory device in work place has not related with any variables. But recognition about the usefulness of repiratory protector has related with recognition of hazard materials in his workplace, for example asbestos. 5. Attitude about severity and susceptability of occupational disease in the asbestos related industry have related with knowledge about hazard materials and occupational disease.

• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.27-33
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• 2013

The consequences of electrode density and thickness for electrochemical performance of lithium-ion cells are investigated using 2032-type coin half cells. While the cathode composition is maintained by 90:5:5 (wt.%) with $LiCoO_2$ active material, Super-P electric conductor and polyvinylidene fluoride polymeric binder, its density and thickness are independently controlled to 20, 35, 50 um and 1.5, 2.0, 2.5, 3.0, 3.5 g $cm^{-3}$, respectively, which are based on commercial lithium-ion battery cathode system. As the cathode thickness is increased in all densities, the rate capability and cycle life of lithium-ion cells become significantly worse. On the other hand, even though the cathode density shows similar behavior, its effect is not as high as the thickness in our experimental range. This trend is also investigated by cross-sectional morphology, porosity and electric conductivity of cathodes with different densities and thicknesses. This work suggests that the electrode density and thickness should be chosen properly and mentioned in detail in any kinds of research works.

• Journal of the Korean Home Economics Association
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• v.45 no.1
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• pp.111-125
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• 2007

By examining the existing Galot products in the market, we aimed to discover areas for new development and lay out the foundational system for establishing a database(DB) of their pattern grading. For the analysis, the team focused mainly on Galot in forms of casual korean traditional clothes, since they have the largest market share. The main accomplishments from this research are as follows. First, because adult females are the largest segment to consider in deciding the size system for grading, we selected three sizes that have to be compatible with the KS Clothing Standardized Sizing. Second, for basic pattern grading, we applied the reference size indicated in KS Clothing Standardized Size, and also used half dart sloper and dartless sloper. Third, we categorized designs according to the presence or absence of a dart, the structure of closure, and the shape of the sleeve and neck. We indicated the grading points with numbers and body area in Korean to make it easier for the users to understand when using the computer system and doing manual work. To further increase the user convenience, we provided diagrams for categorized designs, pattern grading layout, and a table for calculated grading points variation.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.911-918
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• 1993

X-ray photoelectron spectroscopy(XPS) has been empolyed to investigate the structure of PbO-Bi2O3-Ga2O3 glasses. XPS OIS spectra recorded from binary PbO-Ga2O3 glasses clearly showed the presence of two peacks due to bridging and non-bridging oxygens, respectively. Gaussin best-fit deconvolution of the OIS peaks suggested there are substaintial amount of non-bridging oxygens in the structure. Therefore, in addition to the glassforming and charge compensating roles of PbO as suggested from the previous works, role of PbO as network modifiers needs to be considered. Addition of Bi2O3 to binary glasses resulted in the rapid decrease in the amount of non-bridging oxygens as well as in values of FWHM (Full Width at the Half Maximum intensity). It is believed that Bi2O3 form distorted BiO6 octahedra and therefore, work as intermediates. Infrared spectra also suggested that Ga2O3 behave as network-formers in the form of GaO4- tetrahedra.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.395-403
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• 2016

A cylinder-type underwater vehicle for military use that is running near the free surface at the final homing stage to hit a surface ship target is affected by wave force and moment. Since wave can affect an underwater vehicle running at the depth less than half of the modal wave length, it is important to confirm that the underwater vehicle can work well in such a situation. In this paper, wave force and moment per unit wave amplitude depending on wave frequency, wave direction, and vehicle's running depth were calculated by 3-Dimensional panel method, and the numerical results were modeled in external force terms of six degrees of freedom equations of motion. Motion simulation of the underwater vehicle running in various speed, depth, and sea state were performed.

• Journal of Power Electronics
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• v.15 no.2
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• pp.327-337
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• 2015

This study discusses the design of a parallel-operated DC-DC single-ended primary-inductor converter (SEPIC) for low-voltage application and current sharing with a constant output voltage. A coupled inductor is used for parallel-connected SEPIC topology. Generally, two separate inductors require different ripple currents, but a coupled inductor has the advantage of using the same ripple current. Furthermore, tightly coupled inductors require only half of the ripple current that separate inductors use. In this proposed work, tightly coupled inductors are used. These produce an output that is more efficient than that from separate inductors. Two SEPICs are also connected in parallel using the coupled inductors with a single common controller. An analog control circuit is designed to generate pulse width modulation (PWM) signals and to fulfill the closed-loop control function. A stable output current-sharing strategy is proposed in this system. An experimental setup is developed for a 18.5 V, 60 W parallel SEPIC (PSEPIC) converter, and the results are verified. Results indicate that the PSEPIC provides good response for the variation of input voltage and sudden change in load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.370-371
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• 2007

To investigate the ZnO thin films which are interested in the next generation of short wavelength LEDs and Lasers and UV photodetector with p-type inversion layer, the ZnO thin films were deposited by. RF sputtering system. Substrate temperature and work pressure is $100^{\circ}C$ and 15 mTorr, respectively, and the purity of ZnO target is 5N. The ZnO thin films were deposited at $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, and $400^{\circ}C$. For sample deposited at $300^{\circ}C$, we observed full width at half maximum (FWHM) of 0.240 and good surface morphology.

• Animal Systematics, Evolution and Diversity
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• v.19 no.1
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• pp.111-117
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• 2003

Some hydromedusae were collected from Shiwhaho (Kyonsgi-do), Korea Strait and Yeosu, Korea during years 2000-2002. They were identified into Sorsia tubulosa (M. Sars, 1835) of the order Anthomedusae, and Liriope tetraphylla (Chamisso and Eysenhardt, 1821) of the order Trachymedusae respectively. They are new to the Korean fauna. The order Trachymedusae is first recorded in Korea. The long tube-like manubrium and four marginal tentacles are characteristics of S. tubuloso. In L. tetraphylla, the four triangle-shaped gonads and their positions upon half of surface of subumbrella, the seven blind centripetal canals in a quadrant and the long fat manubrium are its distinct characteristics. Resulting from this work, the Korean hydromedusae identified so far consist of 13 species of 11 families in five orders.

• Journal for History of Mathematics
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• v.30 no.1
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• pp.17-29
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• 2017

This paper is concerned with the $Ces{\grave{a}}ro$ summability of Fourier series. Many authors have studied on the summability of Fourier series up to now. Also, G. H. Hardy and J. E. Littlewood [5], Gaylord M. Merriman [18], L. S. Bosanquet [1], Fu Traing Wang [24] and others had studied the $Ces{\grave{a}}ro$ summability of Fourier series until the first half of the 20th century. In the section 2, we reintroduce Ernesto $Ces{\grave{a}}ro^{\prime}s$ life and the meaning of mathematical history for $Ces{\grave{a}}ro^{\prime}s$ work. In the section 3, we investigate the classical results of summability for Fourier series from 1897 to the mid-twentieth century. In conclusion, we restate the important classical results of several theorems of $Ces{\grave{a}}ro$ summability for Fourier series. Also, we present the research minor lineage of $Ces{\grave{a}}ro$ summability for Fourier series.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.269-274
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• 2008

Consuming regular meals has been studied in relation to better health, while higher regularity of eating-out has been linked to obesity. This study examined whether acculturation was associated with regularity of meals, eating-out, and overweight in Korean Americans. Pre-tested questionnaires were mailed to a U.S. national sample with Korean American surnames, and 55% of the deliverable sample responded, producing 356 usable questionnaires. Acculturation was measured using a two-culture matrix model and Gordon's theoretical work, and showed there were three distinct groups (acculturated, bicultural, and traditional). Only 36% reported that they regularly ate three meals a day. Breakfast was the least frequent meal of the day with 43% reporting eating breakfast everyday. More than half (58%) reported that they usually eat out or get take-out food at least once a week. After controlling for age, sex, income, education, and working status, higher acculturation was related to greater regularity of eating-out, but not meal regularity. A total of 28% of men and 6% of women were overweight (BMI>25), and there were significant and positive relationships between body weight status and acculturation in men but not women. However, no significant relationships between frequency of meals and eating-out and overweight status were present. This study did not find significant relationships of meal regularity and eating-out with body weight, however, given the positive relationship between acculturation and eating-out among the subjects and the well-established relationship between eating-out and obesity, nutrition education about skipping meals and eating-for Korean Americans may be useful to prevent such relationships from developing.