• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.606-612
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• 2019

The main causes of subsidence and sinkholes in the lower part of urban roads are sewage line foundation and inadequate compaction of backfill material. This leads to many problems, such as the breakage of joints in sewer pipes, poor connection, pipe breakage, and cracks. To solve this problem, the support factor related to the sewer foundation and the safety factor according to the excavation depth were evaluated. For the foundation of rigidity tolerance, crushed stone foundation, and abandoned concrete foundation, a recently newly developed site assembly-type lightweight plastic foundation were used. Backfill materials were applied on site (sandy soil and clayey soil) and fluid backfill was recycled onsite. To evaluate the depth of excavation and the safety factor of each sewer pipe foundation, the design load considering the load factor and the support factor was evaluated. The support coefficients were 0.377 for a crushed stone foundation, 0.243 and 0.220 for an abandoned concrete foundation ($180^{\circ}$ and $120^{\circ}$), and 0.231 for a lightweight plastic foundation and fluid backfill. Overall, the safety factor was low when using the crushed stone foundation, and the safety rate was the highest when the foreclosed concrete foundation ($180^{\circ}$) was used. In addition, when the combination of lightweight plastic and fluid backfill materials was used, the safety factor was higher than that of abandoned concrete foundation ($120^{\circ}$), which means that the newly developed lightweight plastic foundation can be used as another alternative base of a steel pipe.

• Korean Journal of Veterinary Service
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• v.22 no.3
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• pp.221-237
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• 1999

To investigate the specificity of rapid slide agglutination test for pullorum-gallinarum diseases and to obtain a basic data for avian salmonellosis control, salmonella isolation was peformed for the layer chickens positively reacted in pullonlm-typhoid agglutination test. The biochemical, serological and antimicrobial properties of the isolates were examined. The results obtained through this study were summarized as follows; 1. Of 2,384 chickens tested by the agglutination test, 606 chickens (25.4%) were positive reactors. 154 of 606 reactors and 49 of the non-reacting chickens were investigated for salmonella isolation, resulting in isolation of 68 strains of salmonellae from 27 chickens. 2. By organs, the isolation frequency from liver, cecum, spleen, ovary and gall bladder showed 8.9% (18 strains), 8.9% (18 strains), 7.4% (15 strains), 4.4% (9 strains) and 3.9% (8 strains), respectively. 3. By culture medium the combination of selenite broth and MacConkey agar revealed the highest isolation rate and the enrichment culture by delayed secondary enrichment culture method was found the most effective for salmonella isolation. 4. The serotypes of 68 salmonella isolates were identified as 3 strains of S pullorum, 24 strains of S gallinarum, 15 strains of S typhimurium, 8 strains of S enteritidis, 7 strains of S paratyphi A, 5 strains of S typhimurium and 6 strains of the other salmonellae. 5. The serotypes of 8 salmonella strains isolated from 49 chickens non-reacting in pullorum-typhoid agglutination test were identified as 3 strains of S typhimurium and 5 strains of S infantis. 6. When 24 chickens of which 68 strains of salmonellae isolated were examined by microplate agglutination test, the average antibody titer for pullorum antigen was $2^{5.25}$. The chickens at antibody titer between $2^3$ and $2^5$ showed the higher frequency of isolation as compared with the chickens at the other titers. 7. When salmonella isolates were tested the antimicrobial drug sensitivity by disk diffusion method, S paratyphi A were highly sensitive by 100% to ATM and GM, S typhimurium, by 88% to AM, CIP, IMP and TN, S infantis, by 100% to AM, CRO, ENR and PIP, S enteritidis,by 100% to IMP and PIP, S pullorum, by 100% to ATM, CRO, ENR and PIP and S gallinarum, by 92% to CRO, CIP and PIP.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.10
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• pp.1126-1135
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• 2007

This paper presents the varactor-tuned miniaturized hairpin tunable filter with a single control voltage. The previously proposed miniaturization method is a very straight-forward method to miniaturize a parallel coupled-line filter. In this paper, the miniaturized hairpin tunable filter is proposed with the constant ratio rule of that the capacitances of the each stage always have constant ratio without any dependency to miniaturized electrical length. To show the validity of the proposed method, a 3rd order 0.5 dB ripple Chebyshev fitter with a center frequency of 900 MHz and a fractional bandwidth(FBW) of 10 % was designed and fabricated. The fabricated filter was based on CER-10 substrate of Taconic Inc. with 1SV277 varactor diode of Toshiba Inc. The center frequency of the fabricated filter can be changed from 606 MHz to 944 MHz, 338 MHz with the control voltage from 0.5 V to 4 V. The insertion loss of the proposed filter is increased with the increment of the control voltage, and the filter characteristics are well reserved expect of slight change of the bandwidth with the various control voltage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.276-285
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• 2017

The purpose of this study was to verify the effects of emotional labor on casino dealers' burnout and depression. Burnout is a big problem which thwarts their professionalism and effectualness and the effectiveness of the service they provide. Depression is a core factor which affects one's mental health. To analyze the effects of emotional labor on casino workers' burnout and depression, we conducted a survey of 606 casino dealers of H resort and analyzed the results. Burnout was measured in terms of the client-related burnout and work-related burnout by the Copenhagen Burnout Inventory (CBI), and depression was measured by the Beck Depression Inventory (BDI). The research findings are as follows. First, the level of emotional labor (3.50) was higher than the mid-point on the 4 point Likert scale, and the work-related burnout (3.86) and client-related burnout (3.91) were higher than the mid-point on the 5 point Likert scale. Second, emotional labor was correlated to their depression and burnout. Third, emotional labor showed a significant difference according to gender, while burnout showed significant differences according to age, position and term of service. Fourth, emotional labor had an effect on the casino dealers' burnout and depression. We discussed the implications of these findings and possible strategies to alleviate this situation, for example, the passing of a law and development of an employee assistance program (EAP) to prevent their burnout and reduce their depression.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.387-396
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• 2020

The purpose of this study is to identify the variables of metropolitan and provincial offices of education that affect the academic achievement of unit schools, and to predict how academic achievements dynamically change with the support of offices of education. The results of academic achievement of 606 general high schools in 16 metropolitan and provincial offices of education(rates of attaining more than normal education in Korean, English, and mathematics subjects) were analyzed using a multi-level model and system dynamics. As a result of the analysis, it was confirmed that the provincial and provincial offices of education's efforts to increase the efficiency of local education finance, the efforts to reduce teacher administration, and the facilitation of faculty training were the variables of the provincial and provincial offices of education. In addition, through policy experiments, efforts to revitalize teacher training were the most influential factors in academic achievement of unit schools, followed by efforts to streamline local education finances and to reduce the administrative work of teachers. In order to improve the academic achievement of unit schools, the functions of the metropolitan and provincial offices of education should be strengthened based on the education accountability, and policies need to be established in the mid- to long-term perspective.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.606-620
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• 2015

The aim of this study is to identify whether college students' self-discrepancy has an effect on their well-being and to verify the moderating effect of social support on the relation between self-discrepancy and well-being. For this study, the preliminary research was conducted in the way that questionnaire tests on self-discrepancy, well-being, and social support were administered to 587 college students in Busan and Gyeongnam province. The test results were analyzed by means of SPSS 21.0 program. First, average and standard deviation were analyzed to examine the general characteristics of self-discrepancy, well-being and social support. Second, correlation analysis was used to examine the relationships between variables. Third, hierarchical multiple regression analysis was used to examine the moderating effect of social support on the relation between self-discrepancy and well-being. The conclusions drawn from the analysis are as follows. First, self-discrepancy had a significant negative correlation with well-being and social support had a significant positive correlation with well-being. Second, contrary to the research hypothesis, social support had no moderating effect on the relationship between self-discrepancy and well-being. Based on these findings, the implications and the limitations of the research findings were discussed, and recommendations for future research were provided.

• Membrane Journal
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• v.5 no.1
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• pp.35-43
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• 1995

For several years lots of attempts have been made to establish the liquid membrane-based techniques for separations of gas mixtures especially containing carbon dioxide. A more effective system to separate $CO_{2}$ from flue gases, a circulatory hollow-fiber membrane absorber(HFMA) consisting of absorption and desorption modules with vacuum mode, has been considered in this study. Gas-liquid mass transfer has been modeled on a membrane module with non-wetted hollow-fibers in the laminar flow regime. The influence of an absorbent flow rate on the separation performance of the circulatory HFMA can be predicted quantitatively by obtaining the $CO_{2}$ concentration profile in a tube side. The system of $CO_{2}/N_{2}$ binary gas mixture has been studied using pure water as an(inert) absorbent. As the absorbent flow rate is increased, the permeation flux(i.e., defined as permeation rate/membrane contact area) also increases. The enhanced selectivity compared to the previous results, on the other hand, shows the decreasing behavior. It has been found obviously that the permeation flux depends on the variations of pressure in gas phase of desorption module. From an accurate comparison with the results of conventional flat sheet membrane module, the advantageous permeability of this circulatory HFMA can be clearly ascertained as expected. Our efforts to the theoretical model will provide the basic analysis on the circulatory HFMA technique for a better design and process.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.91-97
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• 2007

Recently, during the past five years, accidents of gas boiler using city gas have occurred 7.4 times more than those which use LP gas. The number of accidents has increased since the use of city gas boilers has increased. These boiler accidents resulted in 87% death from poisoning of CO, and casualty of the accidents was 4.3 times more than that of other types of accident. Hence this study makes the cause of accidents clear by separation the exhaust tube which is the cause of CO poisoning. Also, this study will establish the safety of heat-resistant silicon through testing the performance of heat-resistant silicon. The experiment showed that common silicon started hardening at $56^{\circ}C$ while the heat-resistant silicon did not begin carbonization until $606^{\circ}C$. Besides at the temperature of $150^{\circ}C$ which is the normal temperature of exhaust tube, common silicon leaked on the pneumatic test after deterioration, but the heat-resistant silicon maintained its original property. With these results, we judge that we can reduce the casualty by CO poisoning if we use the heat-resistant silicon to the connector of he exhaust tube.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.583-593
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• 2019

The purpose of this study was to investigate the relation between and subjective instability pain behavior (SIPB) and physical instability test(PIT) according to the presence of characteristic past histories(CPH) in people with chronic low back pain(CLBP). Forty CLBP subjects participated in this study. The presence of four characteristics past histories(long term history, traumatic experience, sports activities, neurologic sign) were examined. According to presence number(PN) of CPH, subjects were divided into 5 groups[group 1(PN:0): n=8, group 2(PN:1): n=8, group 3(PN:2): n=8, group 4(PN:3): n=8, group 5(PN:4): n=8]. After 16 items were examined for the SIPBs, then Seven PITs were conducted, and the results were scored. The SIPBs and PITs were compared according to the presence numbers of CPH, and the relation between them was analyzed. There was a significant difference(p<.05) in both SIPB scores and PIT scores in the comparison of groups according to the presence number of CPH. There was high positive correlation between the presence numbers of CPH and SIPB score(r=.819, p=.000) and PIT score(r=.606, p=.000). Also, there was a correlation between SIPB score and PIT score(r=.571, p=.000). Based on the findings in the present study, the presence of three or more CPH in people with CLBP may be a useful variable in the diagnosis of lumbar instability. The combined findings of the three variables such as CPH, SIPB, and PIT can improve the accuracy of lumbar instability diagnosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.606-612
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• 2011

The purpose of this study was to investigate certain heavy metals (Hg, Pb, Cd, Cu) in 144 samples of cephalopods, to identify weekly heavy metal intakes and to evaluate potential health risks. The average concentrations in the arm, expressed in mg/kg, were: Hg 0.017 (less than the limit of detection (LOD) to 0.059), Pb 0.024 (less than the LOD to 0.092), Cd 0.030 (less than the LOD to 0.627) and Cu 2.536 (less than the LOD to 5.837). The average concentration in the internal organs, expressed in mg/kg, were: Hg 0.063 (from 0.008 to 0.543), Pb 0.579 (less than the LOD to 2.344), Cd 15.200 (from 0.654 to 75.29) and Cu 201.706 (from 2.412 to 856.4). Heavy metal concentrations were higher in the organs than in the arm. Of the four heavy metals, the ratio of internal organs to arm was highest for cadmium. The weekly intakes of Hg, Pb, Cd and Cu from Octopus minor were 0.2%, 0.08%, 0.20% and 0.00%, respectively from the arm, and 1.0%, 0.96%, 92.28% and 0.05% from the internal organs as compared to PTWI (provisional tolerable weekly intakes) established by the FAO/WHO Expert Committee for Food Safety Evaluation.