• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.52-58
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• 2023

With the increasing awareness of the importance of carbon neutrality in response to global climate change, the utilization of hydrogen as a carbon-free fuel source is also growing. Hydrogen is commonly used in fuel cells (FC), but it can also be utilized in internal combustion engines (ICE) that are based on combustion. Particularly, ICEs that already have established infrastructure for production and supply can greatly contribute to the expansion of hydrogen energy utilization when it becomes difficult to rely solely on fuel cells or expand their infrastructure. However, a disadvantage of utilizing hydrogen through combustion is the potential generation of nitrogen oxides (NOx), which are harmful emissions formed when nitrogen in the air reacts with oxygen at high temperatures. In particular, for the EURO-7 exhaust regulation, which includes cold start operation, efforts to reduce exhaust emissions during the warm-up process are required. Therefore, in this study, the characteristics of nitrogen oxides and fuel consumption were investigated during the warm-up process of cooling water from room temperature to 88℃ using a 2-liter direct injection spark ignition (SI) engine fueled with hydrogen. One advantage of hydrogen, compared to conventional fuels like gasoline, natural gas, and liquefied petroleum gas (LPG), is its wide flammable range, which allows for sparser control of the excessive air ratio. In this study, the excessive air ratio was varied as 1.6/1.8/2.0 during the warm-up process, and the results were analyzed. The experimental results show that as the excessive air ratio becomes sparser during warm-up, the emission of nitrogen oxides per unit time decreases, and the thermal efficiency relatively increases. However, as the time required to reach the final temperature becomes longer, the cumulative emissions and fuel consumption may worsen.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.2
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• pp.137-168
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• 2020

Air passengers may be compensated for damages based on the above agreement when the passenger suffers an accident to the extent that they are recognized as an accident under Article 17 of the Montreal Convention in 1999. If a flight or cabin crew and passengers both undergo an accident, passengers are subjected to compensation under the Montreal Convention however flight cabin crews will be compensated by the Labor Law, which is the governing law in the labor contract with the airline. The flight or cabin crew boarding the aircraft work is on a work contract, not a passenger transport contract. Therefore, if the flight or cabin crew on the aircraft is injured due to an accident, and the air carrier is liable for default due to a labor contract, the Labor Law, workers or survivors claim damages due to illegal acts against the employer. In which case, civil law will apply. In this regard, if a Chinese cabin crew working for a Chinese airline dies due to an accident in the Republic of Korea, whether the family of the deceased claims damages against the Chinese airline or not has international court jurisdiction in the Republic of Korea, which is the place of tort. We examined whether it is the law of the Republic of Korea or whether it's the Chinese law, the law applicable to the work contract, is applied. Also, Seoul District Court 1995.5.18. The sentence 94A 14144 was found that if the injured crew during the flight work was not satisfied with the insurance compensation under the Labor Standards Act and the Industrial Accident Compensation Insurance Act, he could claime to damage under the civil law against an air carrier or third parties responsible for the accident. This law case shows that you can claim a civil damage as a cause. In case of death due to an existing illness while on the way to work, the Korea Workers'Compensation and Welfare Service did not recognize the death of the deceased as an occupational accident, and the trial was canceled by the parents of the deceased for the survivor's benefit and funeral expenses. (Seoul Administrative Court 2017.8. 31. Although the sentence was judged as an occupational disaster in 2016, the 2016 8816 Decision), it was defeated in the appeals court (Seoul High Court 2018.7.19.Sentence 2017 No. 74186) and I criticized the judgment of the appeal by analyzing the deceased's disease and related the cause of it to workload. Sometimes, a flight or cabin crew is on board not for the flight duty such as transferring to another flight or returning to the home base or lay-over place after their scheduled flight, this is called "Deadheading". If the crew who is not considered the same as a passenger, but is not on duty, is injured in an accident, does the crew claim compensation for damages under the labor contract or whether the Montreal Convention is applied to the passenger. In conjunction with the discussion, there was a similar case, In re Mexico City Aircrash of October 31, 1979, 708 F.2d 400 (9th Cir. 1983), Demanes v. United Airlines, 348 F.Supp. 13 (C.D.Cal. 1972), Sulewski v. Federal Express Corp., 749 F.Supp. 506 (S.D.N.Y. 1990) and reviewed by the European Court of Justice (CJEU) at Wucher Helicopter GmbH and Euro-Aviation Versicherungs AG v. After examining several acts in several countries it's undeniably crucial to clearly understand the definition of "passenger" as stated in the Fridolin Santer case.

• Journal of Korean Society of Steel Construction
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• v.27 no.6
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• pp.503-511
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• 2015

In long span steel structure, the plate girder reinforced with stiffeners are commonly used. When choosing the cross section with deep depth of girder as well as narrow width, however, out of plane buckling can be a problem due to web slenderness. In an effort to solve this issue, current study determined the applicability of using corrugated web girder with deep depth as bending member, which is generally being utilized in both factory and warehouse nationwide. To accomplish this, we performed the loading test of H-shaped beam with sinusoidal corrugated web. Corrugated web CP-2.3 specimen exhibited 12% less maximal bending strength but CP-3.2 specimen exerted 24% increase in strength compared to plate web P-4.5. this result indicates that corrugated web provides enough strength even with unfavorable width-thickness ratio of plate. And bending as well as shear strength estimated by the Eurocode (EN 1993-1-5) were compared with both bending strength by loading test and shear strength estimated by KBC2009. In case of eurocode, increase in plate thickness did not help in bending performance improvement. moreover, shear performance was sensitive to the thickness of the web folds and the shape of the web plate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.991-998
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• 2013

The fuel injection pipe of a common rail system used in a clean diesel vehicle plays a role in supplying fuel from a rail to the injector of each cylinder connecting the engine under a repeated internal pressure. The fuel injection pressure is increased to over 200 MPa for satisfying EU emission standards and improving fuel efficiency, and a heading process and an autofrettage process are required for preventing folding defects and improving fatigue life. In this study, the flow stress and SN data of the material of the pipe are obtained through a tensile test and a fatigue test. The heading process for checking the folding defects of pipe ends is performed by using FEA. Furthermore, the optimal design of the autofrettage process for improving fatigue life considering not only the compressive residual stresses of the inner surface but also the tensile residual stresses of the outer surfaces of the pipe under the repeated internal pressure is performed by using FEA. To verify the process design, fatigue analysis for the autofrettaged pipe is performed.

• Korean Journal of Community Nutrition
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• v.20 no.5
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• pp.362-374
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• 2015

Objectives: This study was performed to investigate the effects of overestimation of their own body shape on weight control behaviors, mental condition, physical activity, dietary behavior, health-related quality of life, and nutritional status among young Korean females. Methods: A total of 1,514 women aged 20-39 years who are not pregnant and lactating among those who participated in the Fifth Korea National Health and Nutrition Examination Survey (2010~2011), were analyzed and grouped into underestimation (n=120), normal estimation (NE, n=840), and overestimation (OE, n=554), based on their body perception compared to actual percent ideal body weights. Variables were compared between OE group and NE group. Results: The subjects in OE group were significantly younger (29.5 vs. 30.5 years, respectively p < 0.05) and had lower body mass index (20.9 vs. 22.2 respectively, p < 0.01), health-related quality of life measured by EQ-5D (EuroQol-5 Dimension)(0.97 vs. 0.98 respectively, p < 0.05), nutrition adequacy ratio (NAR) of protein (0.91 vs. 0.93 respectively, p < 0.05), phosphorous (0.93 vs. 0.96 respectively, p < 0.05), and iron (0.70 vs. 0.75 respectively, p < 0.01), and index of nutrition quality (INQ) of iron (0.84 vs. 0.89 respectively, p < 0.05) compared to those in the NE group. The results of logistic regression showed that unmarried status (OR 1.32; 1.01~1.72) and severely underweight/underweight status (OR 1.94; 1.01~3.75)/(OR 1.81; 1.34~2.45) were significantly related to the probability of overestimation by the subjects. Significantly more women in OE group practiced fasting, skipping meals, and taking prescribed pills to lose body weights and had skipped breakfast compared to those in the NE group. Conclusions: The results of this study suggested that the Korean young women's distorted perception of own body shape may be associated with undesirable weight control behavior, low quality of life, and lower nutritional status. Therefore, nutrition education for this group should include information on correct body shape perception and its importance.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.3
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• pp.501-512
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• 1999

The aim of this study was to utilize the 20 steps in the three phases from the book, 'Twenty steps for developing a Healthy Cities Project $2^{nd}$ Ed., 1995, WHO/EURO' to survey Healthy Cities to identify the similarities and differences by implementation rates and perceived significances among Healthy Cities worldwide. For this study, a self-administered questionnaire was developed based on the book. The questionnaires were delivered by air-mail and e-mail to 213 Healthy City coordinators or directors in 43 nations from Jan 13 to Feb 10, 1999. The responses were gathered up until March 31 from 40 Healthy Cities in 17 nations, mostly in the USA and in the European regions. The main results are as follows; Overall the perceived significances were higher for healthy cities with higher implementation rates and there were significant differences for 'set-up office', 'plans strategy', 'increase health awareness', 'mobilize intersectoral action', and 'secure healthy public policy'. 1. According to national health system, the implementation rate, perceived significance and implementation ability of the 20 steps were higher in the healthy cities with a comprehensive-type health system as compared to those with an entreprenetrial & permissive health system. Overall there were significant differences in the steps 'mobilize intersectoral action', and 'secure healthy public policy'. steps which were predominant in the healthy cities with a comprehensive-type health system. There was no concordance in the ranks of implementation rate and perceived significant score. 2. According to the length of implementation time, the perceived significance and implementation ability were higher in healthy cities with more than 6 years compared to those with less than 6 years, although implementation rate was the same. Overall there was a significant difference in 'secure healthy public policy' the step which was predominant in the healthy cities with more than 6 years of implementation. 3. According to population covered by the Healthy City Project, the implementation rate and implementation ability were higher in healthy cities with more than a population of 100 thousand. There was no significant difference in perceived significance, but there were differences in the following, 'find finances', 'set-up office'. 'mobilize intersectoral action' in the implementation rate and implementation ability. These three steps were predominant in the healthy cities with a population of more than 100 thousand. 4. The population covered by the Healthy City Project was the only effective factor influencing the total implementation ability of each healthy city, and it was higher for those cities with a population of more than 100 thousand. In Conclusion, the implementation rate, the perceived significance and the implementation ability were higher in cities with a comprehensive -type health system, with more than 6 years of healthy city experience and with a population of more than 100 thousand. To increase the reliability and the validity of the questionnaire and the results of this study arising from lack of sufficient data, repeated study needs to be considered with a more refined questionnaire delivered to more healthy cities worldwide.

• Journal of the Korea Concrete Institute
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• v.26 no.2
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• pp.211-218
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• 2014

In the design of reinforced rectangular concrete beam structure, the minimum amount of flexural reinforcement is required to avoid brittle failure. KCI code is based on concept of ultimate strength and usually used as a model code. But bridge design code enacted by Ministry of land, transportation and maritime affairs in 2012 is based on concept of limit state and similar to Euro code EN 1992-2. This means that the minimum reinforcement presented in both design codes has different origination and safety margin. When rectangular concrete beams with minimum reinforcement are designed according to EN and KCI codes, the amount of minimum reinforcement specified in EN code is only 76% of that in KCI code. This makes the design engineers to be confused. In this study, flexural tests were conducted on nine beams with the two different minimum reinforcement specified in KCI and EN design codes. In results, the measured ratios of nominal strength to crack strength from the test were about 25% greater than those evaluated from the equations presented in KCI and EN codes. The EN beams having only 76% of the minimum reinforcement for the KCI beams were fractured by rupture of steel reinforcement but in ductile manner. It is confirmed that the minimum reinforcement concrete beams designed according to both codes have enough safety margin in flexural capacity and moreover in ductility.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.87-94
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• 2005

Results from previous studies revealed that metal level in the body is related to certain types of diseases. For example. serum copper level with chronic heart failure, iron and transferrin in the blood serum with acute cerebral vascular diseases, Zn in the CNS, lead with neurotoxicity, hypertension, genetic damage, arsenic with cancer skin lesion, Al with neurobehavioral function (cognitive impairment and memory disorder), and etc. The rate of stroke has increased in recent years and several metals were found to be responsible for causing stroke. This study compared several blood metal concentrations between stroke and non-stroke patients. Patients with stroke (116 samples) and non-stroke (111 samples including lowback pain and others) participated in this study. Total of 227 blood samples were collected and participants completed questionnaires regarding age, gender, occupation, residence, alcohol, smoking, and etc. To be qualified into the stroke group, patients have never experienced stroke previously. Subjects only included ischemic stroke and intracerebral hemorrhage patients diagnosed by brain CT and brain MRI. Patients with high risk of metal exposure such as herbal intake and job related exposure were excluded. 10ml of blood samples were analyzed by ICP-MS method at the Center of Nature and Science at Sangji University. Metal geometric mean (SD) concentrations in blood of study subjects showed higher values, 2.64-36.12%, than WHO reference values in Mn, Ni, Hg, Se, and As. Metal concentration in blood of stroke patients non-adjusted for potential confounders was higher except for Hg and also higher except for Ni in adjusted for potential confounders. Co was significantly higher in stroke patients (p=0.002) than non-stroke patients adjusted for potential confounders. Regression coefficient values of stroke patients was 0.17-8.25 in each metals. Odd ratio of stroke patients had 0.96 (Ni)-2.68 (Co) compared to non-stroke cases. This result means that Co increase of 1 raises the risk ratio of stroke by 2.86 times. Based on the results, metal concentration in blood seems to affect incidence of stroke.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.651-660
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• 2018

The purpose of this study was to investigate the effects of task-oriented circuit training(: TOCT) on upper extremity function and quality of life in chronic stroke patients. 20 stroke patients were randomized and divided into 2 groups: a preservation therapy group and TOCT group. The intervention sessions were given five times a week for four weeks. The Stroke Impact Scale(: SIS), EuroQual-5Domains(: EQ-5D), Fugl-Myer Assessment(: FMA), Motor Activity Log(: MAL), Canadian Occupational Performance Measure(: COPM) were used to measure the upper extremity function and the quality of life. In results, Two groups improved in upper extremity function after the intervention(p<.05). The EQ-5D scores of TOCT group were a significantly higher than preservation group(p<.05). The Ironing, Folding towels, Hang out towels on drying rack in COPM scores in both of performance and satisfaction have improved more than preservation group(p<.05). In conclusion, the TOCT has significant helpful effect to chronic stroke patients. These findings can be used to chronic stroke patient as an intervention for upper extremity function and quality of life.

• The Journal of Internal Korean Medicine
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• v.39 no.1
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• pp.84-96
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• 2018

Objective: This is aprospective clinical case study that includes the administration of Ahnjeonbaekho-tang (AJBHT) to patients who have suffered from Graves' disease for the 8 weeks of the clinical research. Methods: Without administration of an antithyroid drug, AJBHT was administered 3 times a day for 8 weeks. In Case 1, AJBHT without modification was administered and in Case 2, in accordance with the patients' symptoms, a dose of Gypsum Fibrosum was increased by 4g from the beginning of week 2, and further increased by 16 g, for a total of 20 g between week 6 and week 8. Body mass index (BMI), thyroid function test (TFT), thyroid autoantibody test, complete blood cell count (CBC), and blood chemistry (BC) tests were conducted at an interval of 4 weeks, for a total of 3 times during the study. The clinical manifestations, a spectrum of symptoms of the patients, was observed by Wayne's Index, Euro-QOL-5 Dimension (EQ-5D), and Perceived Stress Scale (PSS). Results: In both cases, an acceptable significance of reduction of value in T3, fT4, Thyroid stimulating antibody (TSAb) and Thyroid stimulating hormone receptor antibody (TSH-R-Ab) was observed. After treatment, in TFT, T3 decreased by 31.66%, fT4 decreased by 32.82% in Case 1, and T3 decreased by 43.42%, and fT4 decreased by 37.32% in Case 2. In the thyroid autoantibody test, TSAb decreased by 7.59%, and TSH-R-Ab decreased by 53.19% in Case 1, and TSAb decreased by 33.45%, TSH-R-Ab decreased by at least 7.75% in Case 2. Besides this, there was a decreasing trend of Wayne's index, and a loss of typical symptoms of hyperthyroidism also declared the efficacy. Conclusion: From these results, AJBHT is very effective in the regulation of TFT and improving the symptoms of hyperthyroidism, and is also expected to be an effective alternative to antithyroid drugs for patients who have side effects or drug intolerance.