• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.129-136
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• 2023

The study aims to examine the determinants that affect satisfaction, revisit intention, and recommendation intention with foreign tourists who visited Korea despite the threat of COVID-19. This study employs the survey data collected by the Korea Tourism Organization from 8,135 foreign tourists who visited Korea in 2020. As the survey data contains a mixture of continuous and categorical variables, decision tree analysis can ensure analytical validity for the research. According to the analytical results, the determinants affecting satisfaction are the purpose of the visit and acceptance of self-quarantine during their stay. The factors influencing revisit intention are the purpose of the visit, frequency of the visit, and acceptance of self-quarantine during their stay. The determinants affecting recommendation intention are the purpose of the visit, length of stay, and gender. Based on the results of this analysis, this study not only explains the relationship between these determinants and tourism satisfaction, revisit intention, and recommendation intention, but also suggests implications for revitalizing tourism activities.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.113-118
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• 2014

So many nationwide drinking water treatment plants are under much difficulties by new reinforced discharged effluent standards. Generally, the sludge at thickener should be retended for a long time during usual days. Sometime, the soluble manganese and chloroform may be formed under the anaerobic condition in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. It was necessary to improve the operation conditions and process itself in order to meet water quality standard recently reinforced. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. Sludge aeration prevent particle oxidated Manganese eluting soluble de-oxidated Manganese, excrete formated Chloroform from effluent to air, and improve sludge settling through homogenized sludge particle. We aerated sludge at the conventional water treatment plant, measured Manganese and Chloroform of clarified water at upper sludge, and solid-fluid interface height of sludge in mass cylinder. As a result, contaminant's concentrations of the final effluent was much decreased : 41% of manganese, approximately 62% of chloroform and 35% of sludge volume, compared with non-aeration sludge.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.9-14
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• 2020

This paper aims to figure out the impact of employee's travel experience on their happiness and motivations to work. To this end, targeting 405 employees in Daegu, Gyeongsangnamdo, and Gyeongsangbukdo, SPSS Statistics 18.0 program was applied to analyze. Frist, in travel experience depending on general characteristics of the targets, there was significant difference in gender, educational background, and occupation but there was significant difference in age, marital status, and average income. Second, there was difference in travel experience depending on frequency of domestic travel but no difference in terms of the period of stay. On the other hands, travel experience depending on frequency of overseas travel showd significant difference in sub-factor, human network experience. There was significant difference in overseas travel depending on period of stay. Third, travel experience showed positive relation in employee's motivation to work and happiness. Fourth, as a result of reviewing impact of travel experience on employee's motivations to work and happiness, sub-factors like emotional, behavioral, relational experiences affected motivations to work significantly. Emotional experience and cognitive experience didn't affect significant impact. And sub-factors of travel experience like emotional, cognitive, and behavioral experiences affected happiness significantly. Emotional and relational experience were not significant. From the research above, it turned out that travel experience gives happiness to employees and provokes positive thinking and their motivations to work.

• Journal of the Korean Society for information Management
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• v.38 no.4
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• pp.231-250
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• 2021

Despite the increasing number of international students in Korea, there is a lack of research on the health information-seeking behavior of international students. This study examined the health information search behavior of international students in Korea through a questionnaires and in-depth interviews adopting Critical Incident Technique. Most frequent health information needs that the participants experienced were related to Covid-19 and locating doctors/hospitals. The difficulties in seeking health information were language barriers, lack of knowledge of the Korean medical system, insufficient or overflowing information on the Internet. However, despite the language barrier, international students mainly used Korean sources (friends/family, websites, social media) for searching health information. In order to search health information on Korean websites, they used Google Translator or got help from bilingual friends/family members. The participants who have lived in Korea for a shorter period of time or who have lower Korean language proficiency tend to obtain health information through the community on social networks; whereas the longer the period of residence in Korea and the better the Korean language proficiency, the more likely to use websites. Only 28% of the participants gave positive answers to the question asking their confidence in finding the health information they needed. It is discussed how to help international students find accurate and credible health information.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.502-508
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• 1998

Proinflammatory cytokines such as tumor necrosis factor-$\alpha$(TNF-$\alpha$) have been implicated in myocardial and organ dysfunction associated with postperfusion syndrome. We tested the hypothesis that cytokine productions are depressed by preoperative cortiosteroid injection for cardiopulmonary bypass(CPB) and the postoperative courses will be better than without steriod pretreated cases. Cardiac surgery was performed in randomized blind fashion for 20 patients from June 1996 to September 1996. In the steroid group(n=10), corticosteroid(dexamethasone 1 mg/kg) was injected 1 hour before anesthetic induction, but in the control group(n=10), nothing was injected. Each of groups were sampled 11 times as scheduled for TNF-$\alpha$ bioassays. We have checked EKG, cardiac enzymes(CPK, LDH with isoenzyme), WBC count preoperative day, one day and three days after operation. Viatal signs were continuously monitored for three postoperaive days. In the postoperative period three patients in the control group had elevated body temperature and four patients had hypotension that required considerable intravenous fluid administration. But steroid injected patients showed normal body temperture and acceptable blood pressures without supportive treatment. CPK enzymes rose in control group higher than steroid group at postoperative 1st and 3rd day(CPK; 1122$\pm$465 vs 567$\pm$271, 864$\pm$42 vs 325$\pm$87), and CPK-MB enzymes rose in control group higher than steroid group at postoperative 1st day(106.4$\pm$115.1 vs 29.5$\pm$22.4)(P=0.02). Arterial tumor necrosis factor-$\alpha$ rose during cardiopulmonary bypass, peaking at 5 minutes before the end of aortic cross clamping(ACC-5min) in steroid group(11.9$\pm$4.7 pg/ml), and 5 minutes before the end of cardiopulmonary bypass(CPB-5min) in control group(22.3$\pm$6.8 pg/ml). The steroid pretreated patients had a shorter period of time in respirator suport time, ICU stay day, hospital admission day. We conclude that corticosteroid suppress cytokine production during and after cardiopulmonary bypass, and may improve the postoperative course through inhibition of reperfusion injury such as myocardial stunning and hemodynamic instability.

• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.285-294
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• 2002

The purpose of this study was to evaluate the relationships between purification characteristics and hydraulic conditions, and to clarify the basic and essential factors required to be considered in the construction and management of artificial wetland system for the improvement of reservoir water quality. The artificial wetland system was composed of a pumping station and six sequential plants beds with five species of macrophytes: Oenanthe javanica, Acorus calamus, Zizania latifolia, Typha angustifolia, and Phragmites australis. The system was operated on free surface-flow system, and operation conditions were $3,444-4,156\; m^3/d$ of inflow rate, 0.5-2.0 hr of HRT, 0.1-0.2 m of water depth, 6.0-9.4 m/d of hydraulic loading, and relatively low nutrients concentration (0.224-2.462 mgN/L, 0.145-0.164 mgP/L) of inflow water. The mean purification efficiencies of TN ranged from 12.1% to 14.3% by showing the highest efficiency at the Phragmites australis bed, and these of TP were 6.3-9.5% by showing the similar ranges of efficiencies among all species. The mean purification efficiencies of SS and Chl-A ranged from 17.4% to 38.5% and from 12.0% to 20.2%, respectively, and the Oenanthe javanica bed showed the highest efficiency with higher concentration of influent than others. The mean purification amount per day of each pollutant were $9.8-4.1\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in BOD, $1.299-2.343\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TN, $0.085-1.821\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TP, $17.9-111.6\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in SS and $0.011-0.094\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in Chl-a. The purification amount per day of TN revealed the hi링hest level at the Zizania latifolia bed, and TP showed at the Acrous calamus bed. SS and Chl-a, as particulate materials, revealed the highest purification amount per day at the Oenanthe javanica bed that was high on the whole parameters. It was estimated that the purification amount per day was increased with the high concentration of influent and shoot density of macrophytes, as was shown in the purification efficiency. Correlation coefficients between purification efficiencies and hydraulic conditions (HRT and inflow rate) were 0.016-0.731 of $R^2$ in terms of HRT, and 0.015-0.868 of $R^2$ daily inflow rate. Correlation coefficients of purification amounts per day with hydraulic conditions were 0.173-0.763 of Ra in terms of HRT, and 0.209-0.770 daily inflow rate. Among the correlation coefficients between purification efficiency and hydraulic condition, the percentages of over 0.5 range of $R^2$ were 20% in HRT and in daily inflow rate. However, the percentages of over 0.5 range of correlation coefficients ($R^2$) between purification amount per day and hydraulic conditions were 53% in HRT and 73% in daily inflow rate. The relationships between purificationamount per day and hydraulic condition were more significant than those of purifi-cation efficiency. In this study, high hydraulic conditions (HRT and inflow rate) are not likely to affect significantly the purification efficiency of nutrient. Therefore, the emphasis should be on the purification amounts per day with high hydraulicloadings (HRT and inflow rate) for the improvement of eutrophic reservoir withrelatively low nutrients concentration and large quantity to be treated.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.14-20
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• 2008

In this numerical study, the leakage safety of the LNG tank in which is constructed by membrane inner tank-plywood-polyurethane form-plywood-prestressed concrete structures has been presented for four leakage analysis models. The LNG leak criterion of the tank wall with a storage capacity of $200,000\;m^3$ is analyzed based on the thermal resistance technique. This means that if the cryogenic temperature of a leaked LNG is detected at the outer side of the PC wall, it may be leaked through the wall thickness of the tank. The calculated results based on the thermal resistance method between two walls show that the plywood, PUF, and another plywood walls may block the leakage of the leaked LNG even though the strength of these walls is already collapsed by a leaked LNG pressure. But, the leaked LNG may pass the thickness of the prestressed concrete wall for a period of elapsed time even though the PC outer tank supports the leaked LNG pressure. Thus, the PC outer tank may extend the leakage time of a leaked LNG.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.49-54
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• 2011

This study was conducted to evaluate the performance of methane fermentation from effluent of hydrogen fermentation reactor in anaerobic baffled reactor (ABR) and anaerobic sequencing batch reactor (ASBR). Two reactors were operated at organic loading rate of $1.0kg\;COD/m^3{\cdot}d$ and hydraulic retention time (HRT) of 20 day. Methane production rates of ABR and ASBR for start-up periods were 0.04 L/L/d and 0.19 L/L/d, respectively, whereas maximum methane production rates of ABR and ASBR were 0.25 L/L/d and 0.31 L/L/d, respectively. Removal rates of chemical oxygen demand (COD) in ABR and ASBR for start-up periods were 89% and 92%, respectively. After startup periods, removal rates of COD and volatile solids (VS) in ABR and ASBR were maintained over 90%. The specific methanogenic activity (SMA) increased as microorganism acclimated to the substrate.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.149-150
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• 2023

많은 인원을 필요로 하는 조선업은 선박을 건조하는 현장의 제품들이 복합 공정이면서도 중후장대한 특성을 가지고 있다. 이러한 선박을 건조할 때는 종사하는 작업자 간의 작업 내용에 대한 의논과 방법의 결정에 따른 경험기술의 활용도가 높다. 그래서 작업자별 작업 방법이나 기능의 차이가 많고 그 차이만큼이나 공정 진척이나 품질에 대한 결과도 다르게 나타나게 된다. 하지만 인력 집약도가 높은 조선소 작업인력이 퇴직이나 이직 등으로 발생되는 공백을 내국인으로 채우지 못하고 경험이 없고 소통도 어려운 외국인 작업자로 대체하고 있는 실정이다. 외국계 작업자의 경우 인건비가 낮은 중소기업이나 대기업의 하도급 업체에 고용이 되는데 중소기업의 특성상 기술력의 축적이나 안전작업을 위한 사전 직무교육 등에는 여유가 없어 제한된 기간 동안의 고용이나 단순 업무에만 종사토록 하는 등의 방법으로 활용해왔다. 그러나 외국계 작업자의 고용 비중이 높아지면서 전반적인 생산성의 한계와 불안전 작업에 대한 우려로 그 관심도 높아지고 있다. 외국계 작업자의 경우 생산 현장에서 이루어지고 있는 각종 안전관련 교육이나 행사, 동료간의 소통등에 소외되면서 불안전이 가중되고있고 비자종류에 따라 체류기간이 한정되어 기술력의 유지는 어려운 현실이 될 수 밖에 없다. 이러한 외국계 작업자에게 안전에 대한 수준을 높이기 위한 방안으로 직무별 위험성평가도 작업자의 논높이에 맞게 해야 한다. 현재 활용되고 있는 4가지 위험성평가 방법을 일부 보완하여 안전수준에 맞게 실시하여 작업자 개인별 직무 수행상의 위험성에 대한 이해도가 안전에 미치는 영향을 최소화 하여 안전을 유지시키는 방안을 연구한다. 위험성평가의 취지가 기본적으로 해당 작업자 전원참여라는 중요 요소임을 감안할 때 외국인 작업자의 직무 이해도 점검은 매우 중요하다 하겠다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.2
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• pp.75-81
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• 1985

Inhibitory effects of ammonium nitrogen on the nightsoil digestion were investigated in this study by using laboratory digesters. Inhibitory effects were observed even at a concentration less than 1.5g/1 $NH_3N$. This would suggest dilution of influent nightsoil would be one of the applicable methods, however, increased microbial washout due to the dilution limited applicable organic loading rate. The study results indicated 1 : 1 dilution would be most likely applicable to minimize inhibitory effect up to a loading rate of $5kg\;COD/m^3/d$.