• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.179-181
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• 2017

In this paper, we propose the contents of the visual content of the child's own boundaries and implement the contents based on active learning using touch method. The images consist of four modules, each of which consists of content developments, learning concepts, and learning content. The notion of sexual violence is also aimed at fostering awareness that sexual violence is also an extension of the child's safety. Moreover, the learning content of a learning game improves learning outcomes by receiving a 'compliment' if the game succeeds and receives a 'reward' on the game.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.107-114
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• 2007

Islanding of PV systems occurs when the utility grid is removed but the PV systems continue to operate and provide power to local loads. Islanding is one of the serious problems in an electric power system connected with dispersed power sources. This can present safety hazards and the possibility of damage to other electric equipments. In the passive method, the voltage and frequency of PCC are measured and it determines islanding phenomena if their values excess the allowed limits. If the real and reactive power of RLC load and those of the PV system are closely matched, islanding phenomena can't be detected by the passive methods. Several active methods were proposed to detect islanding operation in the region where the passive method can not detect it. The most effective method is SFS method which was suggested by Sandia National Laboratory. In this paper, a new islanding detection method using automatic phase-shift is proposed and its validity is verified through the simulation and experimental results.

• Nuclear Engineering and Technology
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• v.31 no.5
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• pp.486-497
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• 1999

The local heat transfer coefficient is experimentally investigated for the reflux condensation in a countercurrent flow between the steam-air mixture and the condensate, A single vertical tube has a geometry which is a length of 2.4m, inner diameter of 16.56mm and outer diameter of 19.05mm and is made of stainless steel. Air is used as a noncondensible gas. The secondary side has a shape of annulus around vertical tube and the lost heat by primary condensation is transferred to the coolant water. The local temperatures are measured at 11 locations in the vertical direction and each location has 3 measurement points in the radial direction, which are installed at the tube center, at the outer wall and at the coolant side. In three different pressures, the 27 sets of data are obtained in the range of inlet steam flow rate 1.348∼3.282kg/hr, of inlet air mass fraction 11.8∼55.0%. The investigation of the flooding is preceded to find the upper limit of the reflux condensation. Onset of flooding is lower than that of Wallis' correlation. The local heat transfer coefficient increases as the increase of inlet steam flow rate and decreases as the increase of inlet air mass fraction. As an increase of the system pressure, the active condensing region is contracted and the heat transfer capability in this region is magnified. The empirical correlation is developed by 165 data of the local heat transfer. As a result, the Jacob number and film Reynolds number are dominant parameters to govern the local heat transfer coefficient. The rms error is 17.7% between the results by the experiment and by the correlation.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.151-156
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• 2010

Obesity has become one of the main public health problems. Saussurea lappa (Asteraceae), syn Aucklandia lappa and Saussurea costus, is a well-known herbal medicine that has been used for treating various ailments, such as inflammatory and gastrointestinal diseases. The present study examined the anti-obesity effect of S. lappa extract (SLE) in 3T3-L1 adipocytes and high fat diet (HFD)-induced obese mouse model. SLE significantly inhibited the differentiation from preadipocytes to adipocytes of cultured 3T3-L1 in dose-dependent manner. In addition, SLE significantly decreased the body weight gain and the food efficiency ratio of mice fed HFD during 9 weeks. Further study must be performed for the pharmacological mechanism and safety of SLE as well as the identification of active compound in SLE. Our results revealed that S. lappa suppresses the adipogenesis in cultured cells and the obesity in rodent models. Therefore, S. lappa may be useful toward the development of new potent anti-obesity drugs.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.322-326
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• 1995

General pharmacology of LB20304, a quinolone antibiotic, were examined in terms of general behaviour, cardiovascular, and central nervous system. LB20304 at oral dose of 2,000 mg/kg did not induce significant behavioural changes in mice. In contrast with ciprofloxacin, LB20304 at dose of 20 mg/kg, iv. did not show any observable effects on the blood pressure in rats. Displacement of [$^3$H]muscimol binding to the rat brain synaptic membranes was measured. LB20304 was shown to be about five times less potent than ciprofloxacin in specific GABA receptor binding. Drug interaction between LB20304 and 4-biphenyl acetic acid, an active metabolite of fenbufen, was assessed in mice by measuring convulsion and/or subsequent death. A single oral pretreatment with 4-BPA at 400 mg/kg increased the incidence of convulsion and death after oral administration of ciprofloxacin at the doses of 25, 50, and 100 from zero of five to three of five, two of five, and four of five, respectively, whereas LB20304 alone or combination with 4-BPA caused neither convulsions nor death at the doses of 12.5, 25, 50, and 100 mg/kg, respectively. Quinolones-induced epileptogenic activities were assessed by a direct intracerebral injection of test articles. The CD$_{50}$ values (nmole) are as follows; 169.47, 35.36, 105.29, and 88.67 for LB20304, ciprofloxacin, of loxacin, and lomefloxacin, respectively. From these data, LB 20304 at therapeutic doses seems to be much more safe than any other quinolones tested.d.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.1-16
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• 1999

In this study, questionnaire were made to environment-friendly producers of apples regarding farm management methods in low-input production method. utilizing organic materials, production and marketing of apples with lower agricultural chemical residues. Besides, five apples farms were visited to find out their management situation by employing the low-input production method in order to protect the environment as well as consumer's health. Those five low-input apple farms were scattered in Kyungbuk, Chungnam, and Chonnam Provinces, There were not many low-input apple farms across the nation from the beginning and, as a result, increasing the sample size was basically very difficult. Most of these farms were using 140hrs of labor per 10a, of which 30hrs in pre-season management, 25hrs in plowing and weed control, 15hrs in disease and pest control, 20hrs in harvest and marketing and 50hrs in miscellaneous activities. Relatively, pest control takes much time in that they would spray pesticides 7-10 times a season to control the apple disease, 9 times on the average. The average gross revenue of low-input apple farms was about \2,000,000/10a, and their average yield was 2,000kg/10a, which are 25% and 13% lower, respectively, than the ordinary apple production case. This means the low-input farmers are inefficient in marketing their products. On the other hand, their production costs were 20.4% higher than the ordinary apple farms on the average. Since the imported foreign fruits including apples must use various agricultural chemicals on their way to the export markets, the domestic low-input apples have competitive edge over them in therms of food safety. In order to improve the low-input apple industry, active cooperation is needed among the producers, government and researchers more than ever. Among other things, production cost reduction and quality improvement with lower chemical residues are part of the urgent matters to be done.

• Journal of Distribution Science
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• v.14 no.4
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• pp.127-134
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• 2016

Purpose - Value chain in agriculture refers to direct and indirect activities related to value-added process from raw materials to final products in agricultural industries. In recent years, value chain analysis has become more important in the area of agricultural development. This article reviews the concept and importance of value chain analysis in the context of agricultural development and attempts to suggest improvement strategies. Research design, data, methodology - A literature survey was conducted for value chain analysis for agricultural development. The case of agro-value chain in Cambodia was deeply analyzed based upon interviews with government officers and related experts. Results - It seems that agro-value chain in developing countries are not well developed and does not carry out appropriate functions, compared to developed countries. Because value adding facilities, such as storage, processing and packing plants, milling plants, and etc. are not sufficiently constructed, the quality of agricultural products is low. Especially developing countries may loose opportunities to increase value of their product by exporting their agricultural products as raw materials to neighboring countries. Value adding process is also mainly controlled by traders in local markets or wholesale markets in urban areas. Farmers therefore can get lower share of final value of agricultural products compared to the shares paid to traders. Lastly it is argued that governments of developing countries do not play an active role in developing value chains and do not carry out coordinating functions in an effective and efficient manner. Conclusions - The first step to improve agro-value chain in developing countries is to identify and analyze value chain structure of agricultural products and to make development strategies and implementation programs. For improving value chain of agricultural products in developing countries, it is required to provide not only plans for constructing hardwares, such as wholesale markets, storage facilities, processing and packing plants, and etc., but also plans for improving softwares, such as measures for improving product quality and safety, setting up grade and standard, providing market information, and nurturing producer cooperatives.

• Journal of Radiation Industry
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• v.11 no.1
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• pp.19-25
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• 2017

It is suggested that the dose limit recommended in the Enforcement Decree of Korea's Nuclear Safety Act should not exceed 150 mSv per year for radiation workers. Recently, however, ICRP 118 report has suggested that the threshold dose of the lens should be reduced to 0.2~0.5 Gy and the mean dose should not exceed 50 mSv per year for an average of 20 mSv over 5 years. Based on these contents, $^{123}I$, $^{99m}Tc$, and $^{18}F-FDG$, which are radioisotope drugs that are used directly by radiation workers in the nuclear medicine department in Korea are expected to receive a large dose of radiation in the lens in distribution and injection jobs to administer them to patients. The ED3 Active Extremity Dosimeter was used to measure the dose of the lens in the nuclear medicine and radiation workers and how much of the dose was received per 1 mCi.

• Perinatology
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• v.28 no.1
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• pp.11-19
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• 2017

Objective: Human milk bank is known as best alternative option for sick infants. However, only two human milk banks (HMBs) are working in Korea. In the present study, we evaluated the awareness on the HMB in female health care provider to find out the issues that would help facilitating HMB establishment in Korea. Methods: The survey questionnaire was developed by a team composed with neonatologists, obstetricians, nurses, nutritionists, and health care specialists. The survey was performed for female health care workers in Soon Chun Hyang Cheonan Hospital between March and June in 2016. Eighty-eight of 110 questionnaires were collected and the results were analyzed. Results: Most of subjects were found to have correct knowledge on the breast milk feeding. However, only 49% of subjects had awareness of the presence of HMB. Unfortunately, less than half of them could get information about HMB by official way including mass media. In addition, 76% of subjects were found not to want to use HMB. Most important reason was found as a concern on the safety of donor milk including life style of donors, infection controls, and possible nutritional loss of banked milk. Conclusion: The purpose and function of HMB was not widely educated and it seems to be one of most important reasons why women have negative concept about HMB in Korea. Thus, further study is warranted with more numbers of subjects after active public education about the HMB.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.373-379
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• 2019

AeroMACS spectrum is a national resource internationally allocated by ITU at WRC-07. AeroMACS is an airport broadband mobile communication infrastructure based on WiMAX-based IEEE 802.16e that enables real-time video, graphics, voice, and high-speed data transmission. With the approval of ICAO's development technology standards in 2008, 50 airports in 11 countries have already completed the testing of D-TAXI or A-SMGCS technology using the AeroMACS infrastructure in 2019, starting in the United States in 2009. With many advantages in safety and convenience in terrestrial telecommunications operations, the system is becoming an area of performance improvement for airport operations in accordance with ICAO's ASBU plan. This paper examines the current status of domestic development of AeroMACS and lists service areas applicable to airlines and operators. It also seeks to promote safe and efficient next-generation airport mobile communication system services by presenting feasible partners management in the mobile area and use of aircraft communication systems for active technology development.