• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.9-16
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• 2010

The sampling design for the spatial population studies needs a model assumption of a dependent relationship, where the interesting parameters can be the population mean, proportion and area. We know that the study of an interested spatial population, which is stratified by a geographical condition or shape, and the degree of distort of an estimation area is much useful. In light of this, if auxiliary information of the target variable such as wasted area contaminated by some material and the degree of distribution of animal or plants is available, then the spatial estimator might be improved through the calibration procedure. In this research, we propose the calibration procedure for the spatial stratified sampling in which we consider the one and two-dimensional auxiliary information.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.124-134
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• 1997

As control of plant diseases, insects and weeds were heavily relied on pesticides, residues of pesticides in environment and food supply were recently focused by environmentalists and consumer groups. The reduction of pesticide use was implemented in Sweden, Denmark, Netherland, England, and United States. Therefore, it is very important to discuss environmentally sound systems of weed management including cultural, mechanical, and integrated weed control. Mechanical methods using tillage, cultivation, mulching, burning, mowing, solarization, and UHF are used as one of most effective environmentally sound weed management systems. Cultural practices favoring the crops are excellent weed management measures. Correct seedbed preparation for the soil and cultural system, and use competitive cultivars contribute to weed management. Increasing crop density by higher seeding rate or by narrowing row width and careful attention to optimum fertility to produce vigorous crop plants increase competitiveness of crops against weeds. Crop rotation breaks life cycles of weeds by alternating the crop it must associate with. Herbicides are efficient and profitable to control weeds, but must be part of a total weed management program with use of minimum rate. The best weed management will be an integrated approach including two or more methods to manage weed problems.

• The Journal of Korean Association of Computer Education
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• v.9 no.5
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• pp.13-29
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• 2006

This study is intends to analyze achievements of the Literacy-computer education for the illiterates and to develop more efficient implementation strategies. For this purpose, we collected data of the costomer's satisfaction Ievels and its achievements of this program and analyzed its achievements perception by institutes variables, educational method variables, and individual character variables. Based on this results, we suggest specific strategies of this program for better effectiveness of literacy-computer education for the illeterate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.83-87
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• 2009

Ramjet engine is weak for low frequency combustion instability because of their long air flow passage. A model combustor which has fuel injector and V-gutter shaped flame holder was designed and fabricated in order to simulate a combustion mechanism of ramjet engine, and it could demonstrate combustion instability which might occur in ramjet combustor. The frequency of the instability was very similar to that of acoustic resonance frequency of combustor, and it proved that a typical combustion instability by thermo-acoustic coupling occurred.

• Korean Journal of Environment and Ecology
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• v.8 no.2
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• pp.81-92
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• 1995

The flora of the Chuwangsan National Park was surveyed. The field works was done for three times from February to October, 1994. The total number of vascular plants in this area were surveyed as 433 taxa ; 94 families, 260 genera, 365 species, 60 varieties, 2 subspecies, 5 formas, and 1 cultivars. The twenty seven taxa which were artificially planted could be found at the temple and abandoned cultivated areas. The population of Jeffersonia dubia Benth, one of the rare and endangered plants in Korea, were surveyed and mapped for an ecological monitorings in the future. Since this population is restrictly located in the vicinity of the mountain trails, the protection measures should be urgently needed in the future.

• Korean Journal of Health Education and Promotion
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• v.7 no.1
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• pp.1-9
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• 1990

This paper discusses a new perspective in health approach and the effect of health life on health status, and suggests some points to be improved in the establishment of health policies hereafter. Today's health problems changed from the acute epidemic diseases caused by simple factor to the multifactorial chronic diseases. Therefore, the health approach tries the holistic health approach, that is, the integrative approach by the interdisciplinary cooperation. With the advent of holistic health and holistic medicine in 1970's, the behavioral medicine was born in 1977, which is the interdisciplinary field concerned with the development and integration of behavioral and biomedical science knowledge and techniques relevent to prevention, diagnosis and treatment. As a means to the reducement of the unnecessary medical utilization and medical expense, the medical self care and self-help movement is well under way in the countries of America, England, and Canada, in which lay persons are encouraged to actively function for themselves to prevent, detect and treat common illnesses and to promote positive health habits through the health activation programs such as The Course for Activated Patients and The Health Activated Person. This study shows that the individual health life gives great positive effect to his health status with the reducement of medical expense. These above facts suggest that the preventive health programs such as health education should be developed and strengthened instead of medical care-oriented health policy.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.190-196
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• 2018

Carbon fiber/epoxy composites are typical brittle materials and have low impact properties. Recently, it is important to investigate impact characteristics of carbon fiber composites because of increasing use as automobile parts and high pressure hydrogen vessels of fuel cell electric vehicles for light weight. In this study, the low velocity impact properties of carbon fiber/epoxy composites fabricated by a filament winding method are studied. The low velocity impact properties were measured by performing tests according to ASTM D7136. The low velocity impact simulations were carried out using commercial structural analysis software, Abaqus. The absorbed energy and the delamination shapes were compared between the experimental and simulation results. The numerical analysis method showed that the absorbed energy decreased with the reduced number of cohesive elements in the composite models.

• Journal of the Korean Society of Costume
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• v.61 no.3
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• pp.1-19
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• 2011

In the process of modernization from the traditional Korean Han-bok to today's modernized fashion. The Republic of Korea received the most influences form the United States among other western countries. The U. S. A. was the primary country who helped to release S. Korea from Japanese colonization in 1945, and provided the most economic and military aids after the Korean War in 1950. The purpose of this case study is to find out the traits of Americanization in modern Korean fashion through sociocultural evidences and reference pictures. The Americanization can be defined as the U. S. A. influencing cultures of other countries, and sometimes resulted in the substitution of a given culture with American culture. Americanization generally is a part of westernization. The analogous terms for Americanization, are Coca-colonization, McDonaldization, Starbuckslization, and Hollywoodization. The theories related to Americanization are theory of economic determination, global system theory, conspiracy theory, modernization theory, and theory of dependence. However, Americanization of Korea cannot be explained in one single theory, but only can be explained as a hybrid of two cultures. There also is a critical viewpoint of de-Americanization. Americanization of Korea were studied in three important chronicles, a period of modernization (1945-1950s), a period of industrialization & popularization(1960s-1970s), and a period of consumerization(1980s-present). The traits of Americanization in the process of modernizing Korean fashion, were found as simplicity, functionality, popularity(kitsch & mimicry), anti-traditional ethics(unchastity & skin revealing), and materialism(lavishness & trends).

• Journal of Power System Engineering
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• v.14 no.2
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• pp.34-39
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• 2010

Recently, technical trend for machine tools is focused on enhancement of speed and accuracy. High speedy processing causes thermal and structural deformation of objects from the machine tools. Water cooler has to be applied to machine tools to reduce the thermal negative influence with accurate temperature controlling system. Existing On-Off control type can't control temperature accurately because compressor is operated and stopped repeatedly and causes increment of power consumption and decrement of the expected life of compressor. The goal of this study is to minimize temperature error in steady state. In addition, control period of an electronic expansion valve were considered to increment of lifetime of the machine tools and quality of product with a water cooler. PI controller is designed using type of hot-gas bypass for precise control of temperature. Gain of PI is decided easily by method of critical oscillation response, excellent performance of control is shown with 4.24% overshoot and ${\pm}0.2^{\circ}C$error of steady state. Also, error range of temperature is controlled within $0.2^{\circ}C$although disturbance occurs.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.59-63
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• 2003

This paper describes the conceptual design method of subscale direct-connect test facility for liquid fuel ramjet combustion study and preliminary analysis of test results. The measured pressure signal represents the successful operation of the test facility. The pressure oscillation in combustion chamber shows the dominant frequency of 190Hz, relatively very low frequency to 1L acoustic mode (1200Hz) based on the length of combustor. It is suspected that there were several driving sources, which are vortex street at backward step of combustor, inlet resonance induced by the long length of unchecked inlet, and/or combustor configuration with optical window.