• Journal of the Korean Home Economics Association
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• v.45 no.8
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• pp.105-126
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• 2007

The aims of this study were to examine the actual conditions surrounding the purchasing of online game items and Internet cyberspace items by adolescents the propensity of adolescents to consume these items, to determine the difference in the propensity for high and low consumption of these items among adolescents, and to investigate the characteristics of the adolescents who show a high propensity for the consumption of Internet items. The data for this study were collected from 483 adolescent consumers who were middle school and high school students in the city of Bucheon in Gyeonggi Province. The statistical methods used for the data analysis included frequency, percentage, standard deviation, t-test, and one-way ANOVA. The results of the present study can be summarized as follows. The majority(79.5%) of the students surveyed had had the experience of purchasing items. Most students(67.5%) had a rare frequency of buying ($1{\sim}2$ times in a period of 6 months or less). Nearly half (47.9%) of the students spent less than 1000 won per month on the item(s) purchased. Most of the students purchased items with their parents' permission, but 26.6% of the students bought the items without their parents' permission. Most of the characteristics of the items purchased, such as the major item purchased, payment method, amount purchased per month, average amount spent per buying experience, and whether or not they had their parents' permission differed according to gender, grade level, record, and monthly allowance. The level of propensity to consume the items was not high. The propensity of imitation consumption (1.96) was lower than that of impulsive consumption (2.38) and conspicuous consumption (2.45). Most of the buying characteristics, including the major item purchased, payment method, amount purchased per month, average amount spent per buying experience, parents' permission, grade level, and monthly allowance were different between the high and low propensity for consumption groups.

• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.95-100
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• 2001

To select the section with shoot formation ability, the calli and shoot formation from three sections (first leaf including cotyledonary node, hypocotyl and cotyledon explants) of 5-days-seedlings of soybean were induced on MS medium supplemented with 1.0 mg/L BAP, 3% sucrose, and 0.3% gelrite for one month. The first leaf section exhibited the highest shoot formation rate (51%), followed the hypocotyl section (10%) and the cotyledon section (0%). The shoot formation rates and shoot number of the four excised sections (whole first leaf, a half of the first leaf, a third of the first leaf and only node) of the first leaf were also investigated on the same medium. A half of the first leaf explant and the third of the first leaf explant had higher shoot formation rates (76-80%) and numbers (3-4 / explants) than those in other two explants. Effects of six cytokinins (kinetin, zeatin, BAP, 2iP, PBA, and TDZ) on shoot formation were determined, using the half of the first leaf explants. Zeatin (1.0 mg/L) exhibited the highest in shoot formation rate (94%) and numbers (8 / explant). In addition, the combined effects of three cytokinins (zeatin, BAP, and TDZ; 0.5, 1.0, 2.0 mg/L, respectively) and an auxin (IAA; 0.0, 0.5, 1.0, 2.0 mg/L) were determined. The combination (1:1, v/v) of zeatin (1.0 mg/L) and IAA (1.0 mg/L) exhibited the highest in shoot formation rate (96%) and numbers (16 / explant), twice more than zeatin (1.0 mg/L) alone. The shoot cuttings were transferred and cultivated on the rooting media supplemented with only auxin, IBA at various concentrations. The highest root formation (8 / shoot) was achieved on the medium supplemented with 1.5 mg/L. After 4 weeks of cultivation, the plantlets with an extensive root system were transplanted in pots with a soil mixture of vermiculite and fine sand. Transferred to field, about 75% of the plantlets survived.

• Environmental and Resource Economics Review
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• v.17 no.2
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• pp.349-379
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• 2008

Otters which are the nearly extinct feral animal as well as indicator species of ecological balance of river have a wide variety of public value. The objective of this paper is to estimate non-market value of preservation of otters' habitats in Cheongju Si and Cheong won Gun. In this research, the one-and-one-half bound dichotomize choice method as a contingent valuation methods is used to derive willingness to pay for the preservation of otters' habitats. 311 residents were surveyed to determine their recognition and willingness to pay for preservation of otters' habitats. The results show that the value of preservation of otters' habitats is 5,904 won per house and month.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.451-483
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• 2007

Recently, the problem of noise has received much attention in the urban environment. This paper attempts to measure the economic benefits of urban noise reduction in the metropolitan area. To this end, the dichotomous choice contingent valuation method is applied. In particular, recently proposed one and one-half bound model that reduces the potential for response bias in the double bound model while maintaining much of its efficiency. We surveyed a randomly selected sample of 800 households in the metropolitan area and asked respondents questions in person-to-person interviews about how they would willing to pay for the noise reduction. Respondents overall accepted the contingent market and were willing to contribute a significant amount (997 to 1,778 won), on average, per household per month. This willingness varies according to individual characteristics such as concerns about noise, dwelling area, and income. The aggregate value of the noise reduction in the sampled metropolitan area amounts to approximately 79.26 to 141.35 billion won per year.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.163-173
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• 2023

In this study, topographic change analysis was performed on the Nak-dong River estuary area. The factors affecting the changes in the bathymetry of the Nak-dong River estuary were analyzed using data from the discharge, suspended sediments, and rainfall of the Nak-dong River barrier as analysis data. As a result, erosion and sedimentation are judged to appear repeatedly due to complex effects such as discharge of the estuary barrier of the Nak-dong River and invasion of the open sea waves, and it is judged that there is no one-sided tendency. However, as a result of checking the data in the second half of 2020, it was possible to confirm a large amount of erosion, which is different from the past data. It is clear that this is a result beyond the trend of erosion in the first half and sedimentation in the second half. In the summer of 2020, the rainy season lasted for more than a month and torrential rains occurred, which seems to be due to about three times higher rainfall than other periods, and erosion is believed to have occurred as the discharge increased rapidly compared to the time deposited by river water outflow. In addition, compared to other times, the influence of many typhoons in the summer of 2020 is believed to have affected the topographical change at the mouth of the Nak-dong River.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.179-183
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• 1980

The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate $36\%$ from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, $SH=6.33\;(1-e^{0.2421(t+0.54)})$, where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2, and/or log $DW=-5.8153+7.208{\cdot}log\;SH,\;(5. Size specific gonad output (G) as calculated by condition index of before and after the spawning season, was related to shell height by $G=0.0145+(3.95\times10^{-3}{\times}SH^{2.9861})$. Shell organic matter production (SO) was related to shell height by log $SO=-3.1884+2.527{\cdot}1og\;SH$. Size and temperature specific respiration rate (R) as determined in biotron system with controlled temperature, was related to dry meat weight and temperature (T) by log $R=(0.386T-0.5381)+(0.6409-0.0083T){\cdot}log\;DW$. The energy used in metabolism was calculated from size, temperature specific respiration and data on body composition. The calorie contents of oyster meat were estimated by bomb calorimetry based on nitrogen correction. The assimilation efficiency of the oyster estimated directly by a insoluble crude silicate method gave $55.5\%$. From the information presently available by other workers, the assimilation efficiency ranges between $40\%\;and\;70\%$. Twenty seven point four percent of the filtered food material expressed by energy value for oyster population was estimated to have been rejected as pseudofaeces : $17.2\%$ was passed as faeces; $35.04\%$ was respired and lost as heat; $0.38\%$ was bounded up in shell organics; $2.74\%$ was released as gonad output, $2.06\%$ was fell as meat reducing by mortality. The remaining $15.28\%$ was used as meat production. The net efficiency of energy transfer from assimilation to meat production (yield/assimilation) of a farm population of the oyster was estimated to be $28\%$ during culture period July 1979-April 1980. The gross efficiency of energy transfer from ingestion to meat production (yield/food filtered) is probably between $11\%\;and\;20\%$.

• Tuberculosis and Respiratory Diseases
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• v.84 no.2
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• pp.134-139
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• 2021

Background: Intrapleural urokinase is one of the most widely used fibrinolytic agents in the treatment of complicated parapneumonic effusion (CPPE). However, little research has been performed on the optimal urokinase dosage. The aim of this study was to evaluate the treatment efficacy of half dose urokinase compared with conventional dose urokinase. Methods: We retrospectively enrolled 92 patients with CPPE or empyema who underwent intrapleural urokinase treatment at two tertiary hospitals. Patients received antibiotics, chest tube drainage, and other treatments as part of routine care. The primary outcome was the treatment success rate in the half dose urokinase group (50,000 IU daily for maximal 6 days) and the conventional dose urokinase group (100,000 IU daily). Treatment success was defined as clinical and radiological improvements without surgical treatment or re-admission within one month. Results: Forty-four patients received half dose urokinase, whereas 48 patients were treated with conventional dose urokinase. Both groups were relatively well matched at baseline, excluding higher serum white blood cell count and higher empyema prevalence in the half dose urokinase group. The treatment success rate was not different between the two groups (p=0.048). There were no differences in the rate of in-hospital death and surgical treatment, hospitalization duration, and indwelling catheter duration. In the multivariate analysis, urokinase dose was not a predictor of treatment success. Conclusion: Half dose intrapleural urokinase is equally effective conventional dose urokinase in treating patients with CPPE or empyema.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1284-1286
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• 2001

In this paper, the operating characteristics of a 3 kW class grid-interactive photovoltaic(PV) power system was analysed from January 1998 to December 2000. The construction of the PV system includes a DC/AC inverter for grid connection, PV module, and data Monitoring & Acquisition system. The major results of the field test of the 3 kW class grid-interactive PV system showed that the system utilization rate was 13.83% the conversion efficiency of the inverter was 88% at an over half load, and the PV system generated the electricity more then 300 kWh per month.

• Journal of Home Health Care Nursing
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• v.3
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• pp.39-52
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• 1996

This study presents results of surveys conducted Incheon area using structured questionaire developed by researcher to determine the degree of knowledge, attitude and practice of breast feeding of mothers of infant. The suvjects were mothers of 84 Childs, 1-6 months of age. Results were as follows : 1. More than half of the subjects started breast feeding and breast-bottle feeding(61.9%) 2. Duration of breast feeding was under one month (9.6%), 1-2months(13.7%), 3-4months(5.5%), 5-6months(23.3%) and had continued breast feeding until they were questioned. 3. The 40.5% of mothers'never got information of breast feeding and 21.4% of mother got information of breart feeding through T. V. or radio. 4. Degree of mothers' knowledge of breast feeding was significantly correlated with mothers' attitude of breast feeding (r=.47, p<0.01) and degree of mothers' attitude of breast feeding was significantly correlated with mothers' practice of breast feeding(r=.34, p<0.01).

• Korean journal of food and cookery science
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• v.8 no.1
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• pp.49-56
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• 1992

This study aims to get basic datea on the usual dietary forms of many korean families bringing up either elementary, or junior high or senior high students. Our interest is focused on which factor is decisive in shaping their diet, which way of cooking is preferred and how the korean traditional way of diet is preserved. 407 of housewives of suweon city answered the questions, and the result shows that more than half of them (54.1%) decide the contents of their diet according to their husbands’ taste 77.4% of them regard dinner as the most important meal. The number of side dishes are usually 3 or 4 (57.2%). In preparing their diet, 41% take account of ‘taste’ first, but for many of college graduate housewives ‘nutrition’ is the primary concern. As for main dish, cooked rice (55.3%), and soybean soup (66.1%) are preferred. Both meat and fish are commonly grilled. 83.1% of them enjoy dining out once or twice a month, and when they they dine out, korean-style restaurant is preferred (43.7%). The most frequently used processed food is ham (19.2%), and secondly, ramyon (17.8%).