• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.244-252
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• 2020

The 2008 global financial crisis was triggered by the Lehman Brothers crisis caused by the sub-prime mortgage crisis in the United States This crisis has had an impact on the globe's dry bulk shipping market by reducing dry bulk cargo volume. An oversupply of dry bulk carriers caused a serious recession in the globe's dry-bulk shipping industry and shipbuilding industry. In this situation, the Korean dry-bulk shipping companies were victims of the quagmire of a long recession since the global financial crisis and could not overcome this crisis. This condition forced them into severe financial risk Thus, it caused many shipping companies to file for bankruptcy. In this study, we classified Korean ocean-going dry-bulk shipping companies into two groups, that is, the solvent group and the insolvent group. We also separated the research period before and after the 2008 global financial crisis. Then we investigated the differences in the major financial ratios of the two groups by t-test and found that some financial ratios such as profitability ratios and growth ratios showed the difference between the two groups with statistical significance. The significance of this study is as follow. First, the shipping company management is also crucial for the systematic management of financial strength and business strategy, it is crucial to manage cargo which a high profitable freight. Second, the shipping company should be managed as a company with continued growth through efficient operation and management of ships.

• Journal of the Korean Institute of Gas
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• v.14 no.6
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• pp.15-20
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• 2010

Compressed Natural Gas (CNG) buses have been supplied since the year 2000 in order to resolve severe atmospheric pollution in metropolitan area and contributed on the improvement of urban atmospheric environment. However, it is indispensible to take an adequate measure to guarantee the safety of CNG vehicles because of the possibility of huge fire accident. A receptacle, connecting device between high pressure fuel supply tank and fuel line, plays an important role in CNG supply system. In recent, leakage of CNG from receptacles has been reported. So, the concern about the security and reliability of receptacles has been arisen. Therefore, a lot of efforts to prevent leakage are invested among researchers and the durability of this component should be guaranteed despite repeated operation. This research has performed durability tests of a CNG receptacle regarding the repeated usage, extreme chattering, and continuous full flow test. Although a receptacle used for CNG vehicle satisfies validation requirements in the test results, it has been found that failure in the function of leakage prevention in a receptacle could take place in the case of prolonged exposure to high supply pressure in common quick charging environment on site.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.147-152
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• 2020

Malaria is a potent burden on public healthcare worldwide due to requiring rapid diagnosis and treatment. Nowadays, prompt diagnosis with rapid diagnostic tests (RDTs) has been widely accepted as an effective diagnostic technique in malaria-endemic countries, primarily due to their easy operation, fast output, and straightforward interpretation. The global availability and use of RDTs have gradually grown over recent decades as field-applicable diagnostic tests for the reliable confirmation of malaria infection and proper case management. This study was conducted to evaluate diagnostic performance of 3 commercially available malaria RDT kits : BIOCREDIT^TM Malaria Ag Pf(pLDH), Malaria Ag Pf(pLDH/pHRPII), and Malaria Ag Pf/Pv(pLDH/pLDH) (where pLDH and pHRPII stand for plasmodium lactate dehydrogenase and histidine-rich protein 2, respectively) for the specific detection of Plasmodium falciparum. A total of 1,129 blood samples including 95 blood samples, confirmed as vivax malaria infection by microscopic examinations and a nested-PCR method, were tested for falciparum malaria infection. The overall sensitivity and specificity of Malaria Ag Pf(pLDH/pHRPII), Malaria Ag Pf/Pv(pLDH/pLDH), and Pf(pLDH) for P. falciparum were 99.0% and 100%, 95.8% and 100%, and 100% and 100%, respectively. It is proposed that the 3 RDT kits perform reliable level of diagnostic accuracy of detection for P. falciparum parasites.

• Journal of the Korean Society of Food Culture
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• v.15 no.2
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• pp.79-94
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• 2000

The purposes of this study were to : (a) analyze university students' perception and patronage behaviors to the service quality dimensions, and (b) assist university residence hall foodservices in formulating improved managerial strategies. Questionnaires were hand delivered and mailed to 1,210 university students residing in the residence hall and 13 foodservice managers. A total of 1,011 was usable; resulting in 83.6% response rate. The survey was conducted between October, 1998 and May, 1999. Statistical data analysis was completed using the SAS/Win 6.12 for Descriptive Analysis, $x^2-test$, T-test, ANOVA, and Stepwise Multiple Regression. Forty-seven percent of the respondents indicated that 'taste' was their first priority when choosing a menu. The reasons behind choosing residence hall foodservice were 'location', 'board plan', 'price', 'taste', 'opening hours', and 'menu variety'. The main reasons of dissatisfaction with the residence hall foodservice were 'board plan', 'taste', 'menu variety'. The overall satisfaction score was 2.99 out of 5. The satisfaction score of ${\ulcorner}convenience{\lrcorner}$, ${\ulcorner}food\;quality{\lrcorner}$ and ${\ulcorner}menu\;variety{\lrcorner}$were 3.25, 2.94 and 2.76, respectively. Generally, male students were more satisfied than females. Graduate students and students living in residence halls over six semesters were the most dissatisfied with the residence hall foodservice. Residence hall students were dissatisfied with the variables ${\ulcorner}menu\;variety{\lrcorner}$ and ${\ulcorner}facilities{\lrcorner}$in 'self-operated' operations, whereas ${\ulcorner}food\;quality{\lrcorner}$, ${\ulcorner}menu\;variety{\lrcorner}$ and ${\ulcorner}price{\lrcorner}$ in 'contracted' operations. Foodservice operations with 'less than 1,000 meals serving per day' was the highest satisfaction score(3.36) among other serving sizes. Meal price with 'less than 1,300 won' was most satisfied with students. When overall customer satisfaction and service quality dimensions were analyzed by Stepwise Multiple Regression ${\ulcorner}food\;quality{\lrcorner}$(p<.001), ${\ulcorner}price{\lrcorner}$(p<.001), ${\ulcorner}facilities{\lrcorner}$(p<.001), ${\ulcorner}convenience{\lrcorner}$(p<.001), ${\ulcorner}menu\;variety{\lrcorner}$(p<.001), ${\ulcorner}manager's\;attitude{\lrcorner}$(p<.0l), and ${\ulcorner}atmosphere{\lrcorner}$(p<.01), in decreasing order, significantly impacted on ${\ulcorner}overall\;customer\;satisfaction{\lrcorner}$.

• Journal of Nutrition and Health
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• v.38 no.10
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• pp.880-894
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• 2005

The purposes of this study were to a) measure the IC identified of CFMC (contract foodservice management company) ,b) examine IC circumstance of CFMC, c) evaluate practically IC measurement tool of CFMC, and d) present information for selecting an adequate CFMC to clients. The questionnaires of IC measurement were handed out to 108 CFMCs, there composing of main office employees, foodservice managers, customers, and clients of 207 school,38 hospital, and 86 husiness/industry foodservices. The statistical data analysis was completed using SPSS Win (ver 12.0) for descriptive analysis, t-test, Mann-Whitney U test. First, CFMCs had operational experience for an average of 8 years and 8 months, and served an average of 38,540 meals a day. Most of the respondent companies specialized in the school foodservice field and managed an average of 66 clients for the contract period of 2 years and 3 months. Second, the respondent companies had gotten a score of 77.78 points for the total average, 77.7 points in the large enterprise group and 78.1 points in the small and medium-sized enterprise group. Therefore, the minimum number of points for the accrediting license on Qualification is suggested to be over 70 out of a 100 point scale; this study would be serve as reference for the certification license on qualification. On the level of evaluation category, the scores were 14.15 to 20 points on $\ulcorner$finance$\urcorner$, 19.24 to 25 points on $\ulcorner$customer$\urcorner$, 19.33 to 25 points on $\ulcorner$process$\urcorner$, 14.31 to 20 points on $\ulcorner$human resource$\urcorner$, and 8.6 to 10 point on $\ulcorner$renewal and development$\urcorner$ . $\ulcorner$Renewal and development$\urcorner$ and $\ulcorner$customer focus$\urcorner$ received better grades than other evaluation categories. Third, $\ulcorner$Finance$\urcorner$ indicated similar distribution overall. Small and medium-sized companies had lower grades than large companies on 'market ability' of $\ulcorner$customer$\urcorner$ , but, clients of small and medium-sized companies had higher grade for 'client satisfaction' than large companies. Most of the companies supported 'infrastructure support for foodservice operation' of $\ulcorner$process$\urcorner$ by the main office of CFMCs, but, the branch chain offices of CFMCs were not applied efficiently. Large companies made more effort to improve the 'employee ability' of $\ulcorner$human focus$\urcorner$ than small and medium-sized CFMC. The 'research and development cost' of $\ulcorner$renewal and development$\urcorner$ was increased compared to the previous year. In conclusion, if CFMCs were to perform self-evaluation and a routine checkups by utilizing CFMC's IC measuring tool, improvements in CFMC operational capacities as well as foodservice quality can be noted. (Korean J Nutrition 38(10)'880$\sim$894,2005)

• Journal of Ocean Engineering and Technology
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• v.34 no.5
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• pp.294-303
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• 2020

This study discusses data collection, calculation of wind and wave-induced resistance, and speed-power analysis of an 8,600 TEU container ship. Data acquisition system of the ship operator was improved to obtain the data necessary for the analysis, which was accomplished using SPA (Ship Performance Analysis, Park et al., 2019) in conformation with ISO15016:2015. From a previous operation profile of the container, the standard operating conditions of mean draft were 12.5 m and 13.6 m, which were defined with the mean stowage configuration of each condition. Model tests, including the load-variation test, were conducted to validate new ship performance and for the speed-power analysis. The major part of the added resistance of container ship is due to the wind. To check the reliability of wind-resistance calculation results, the resistance coefficients, added resistance, and speed-power analysis results using the Fujiwara regression formula (ISO15016:2015) and Computational fluid dynamics (Ryu et al., 2016; Jeon et al., 2017) analysis were compared. Wind speed and direction measured using an anemometer were used for wind-resistance calculation and the wave resistance was calculated using the wave-height and direction-data from weather information. Also, measured water temperature was used to calculate the increase in resistance owing to the deviation in water density. As a result, the SPA analysis using measured data and weather information was proved to be valid and able to identify the ship's resistance propulsion performance. Even with little difference in the air-resistance coefficient value, both methods provide sufficient accuracy for speed-power analysis. The differences were unnoticeable when the speed-power analysis results using each method were compared. Also, speed-power analysis results of the 8,600 TEU container ship in two draft conditions show acceptable trends when compared with the model test results and are also able to show power increase owing to hull fouling and aging. Thus, results of speed-power analysis of the existing 8,600 TEU container ship using the SPA program appropriately exhibit the characteristics of speed-power performance in deal conditions.

• Journal of The Korean Ophthalmological Society
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• v.55 no.1
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• pp.1-6
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• 2014

Purpose: To investigate the clinical manifestation of nasolacrimal duct obstruction after radioactive iodine therapy for thyroid cancer. Methods: The authors examined 622 patients who were treated with radioactive iodine therapy after the operation for thyroid cancer from January 2009 to December 2011. Fourteen patients (18 eyes) were diagnosed nasolacrimal duct obstruction based on the lacrimal irrigation test, lacrimal probing test and dacryocystography in our oculoplastic clinic. We analyzed the dose of radioactive iodine therapy, number of treatments, clinical manifestation and treatment type by retrospectively reviewing the patients' medical records. Results: The mean radioactive iodine dose ($215.7{\pm}23.1mCi$, p = 0.01) and the mean number of treatments ($1.36{\pm}0.50$, p < 0.001) were significantly greater in 14 patients who had nasolacrimal duct obstruction than in patients who did not. The average onset of tearing symptoms occurred 10.2 months after radioactive iodine therapy. The mean time between correct diagnosis and therapy was 18.4 months. Three patients (3 eyes) had occlusion at the common cannaliculus and 11 patients (15 eyes) had occlusion at the nasolacrimal duct. Ten patients (13 eyes) underwent endonasal dacryocystorhinostomy for complete obstruction and 4 patients (5 eyes) underwent silicone tube intubation for partial obstruction. Conclusions: Nasolacrimal duct obstruction is a rare complication associated with radioactive iodine therapy for thyroid cancer, thus, clinicians should be aware of this complication and refer patients with symptoms of epiphora to the oculoplastic department for specialized evaluation and treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.22-33
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• 2021

In the case of open phase faults caused by the disconnection of distribution feeders interconnected to a PV system, many problems can occur depending on the core type and wiring method of the grid-connected transformers. Moreover, open phase faults are difficult to detect because the open phase voltage of the existing protection relay (Open Phase Relay (47)) can be maintained, even though a disconnection fault occurred, depending on the wiring method and the iron core type of the grid-connected transformer for a PV system. Therefore, this paper proposes a novel algorithm to detect open phase faults by comparing the currents and phases between the primary and secondary sides of a grid-connected transformer. In addition, this paper presents the modeling of a distribution system and protection devices for detecting open phase faults using PSCAD/EMTDC S/W, and implements a test protection device for detecting open phase faults based on the above-mentioned modeling. The simulation and test results confirmed that the proposed algorithm is useful for detecting open phase faults according to the wiring method and iron core type of grid-connected transformer for a PV system because operation slope and unbalance rate of the primary current exceed the setting value (30[%]) of the protection device.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.350-356
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• 2018

The contact force, which is the dynamic interaction between the pantograph and the catenary, is an important indicator for evaluating the current collecting quality, which is a stable power supply characteristic to the vehicle. In this study, dynamic contact force characteristics of pantograph of HEMU-430X vehicle, which is a power-distributed high-speed train test vehicle, were analyzed according to the catenary tension and compared with the analytical results using the pantograph-catenary interaction model. As a result of comparing the test results with the analytical results, it was confirmed that the average contact force and the standard deviation of the contact force, which are the main dynamic contact force characteristics, coincide relatively well. Using the analytical model, the relationship between the catenary tension and the contact force is presented according to the vehicle speed, and the optimal catenary tension for each operation speed is presented and compared with the international standard. As a result, it was found that the results obtained from the analysis are comparable to those recommended by international standards.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.255-264
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• 2019

Endodontic treatment of primary molars is a great challenge to the dentists because of their complex morphology. However, there have been limited controlled in vivo studies about filling materials for primary teeth. Hence, the aim of this study is to evaluate and compare histologic responses of different calcium hydroxide canal filling materials that are used in daily clinical practice. Pulpectomies were performed in 132 teeth of the dogs. The root canals were randomly filled with either $Vitapex^{(R)}$ (n = 44), $Metapex^{(R)}$ (n = 44), or $Metapaste^{(R)}$ (n = 44). After 4 or 13 weeks, respectively after operation, the dogs were sacrificed, and teeth were processed for histologic examinations. Inflammatory reaction was evaluated and scored in a blind manner. The Fisher's exact test and Kruskal-Wallis test were used to compare the tested groups. In 4-week-group, all inflammatory responses were in normal range except for fibrosis. In 13-week-group, increased response to various inflammation reaction was shown compared to the 4-week-group. However, there were no statically significant differences between the tested groups in all inflammatory reaction. Overall, there were no significant differences among three materials in responses of apical tissues and all of them showed favorable tissue responses.