• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3736-3741
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• 2015

Crash impact test is conducted to verify the crashworthiness of fuel tank. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. The failure of crash impact test can result in serious delay of a entire rotorcraft development because of the design complement and re-production of the test specimens requiring a long-term preparation. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error in the real test. Present study conducts on the numerical simulation of phase I crash impact test using SPH supported by crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the crash load on the skin material, overlap area and metal fitting is estimated to confirm the possibility of acquisition of the design load for the determination of the overlap area and adhesive strength.

• The Korean Journal of Applied Statistics
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• v.6 no.2
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• pp.201-215
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• 1993

The health status of workers in a foundry was analyzed in a study which consisted of evaluations of respiratory health together with environmental measurements. The results from environmental measurements showed values exceeding permissible exposure limits. A t-test was done with log transformed and untransformed data to examine the statistical significance for the noncompliance with exposure standards. For the analysis of categorical health outcomes, $\chi$-square test with 2 $\times$ 2 tables and logistic regression analysis were employed. For continuous variables, multiple linear regression was done against assessed risk factors. Pros and cons of different parameters in the compliance (or noncompliance) testing were presented. Respiratory function did not show any relation with occupational exposures, which may be due to the healthy worker effects. Strategies for controlling time dependent covariates were discussed in relation to the healthy worker effect. The scope of statistical analysis in occupational health studies is still limited in Korea without a suitable external comparison group such as credible vital statistics for the whole nation. Internal comparisons between different exposure status often result in unstable estimates of effect, and proportional morbidity study is discussed as an alternative potential research tool.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.294-299
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• 2001

Objectives : CT-guided stereotactic evacuation for spontaneous intracerebral hemorrhage can minimize the brain damage and can be performed safely and simply under local anesthesia. But that procedure is time consuming and has a risk of rebleeding because of the stress during head pin fixation. So authors describe easy and precise guidelines for FHA of putaminal hemorrhage without stereotactic instrument. Methods and Materials : We analyzed the data of 298 patients who underwent CT-guided stereotactic aspiration of putaminal hematoma in our hospital between January 1990 and December 2000. We divided the patients into three groups according to the location of hematoma : anterior portion, middle portion and posterior portion of putamen. Total number of catheters inserted into the hematoma were 345 and there were with regard to the direction and depth of catheters. Results : Proposed guidelines of catheter insertion to putaminal hemorrhage in our institution. 1) hematoma at the anterior portion of putamen ; Direction of catheter was the midpupillary line of the eye and the point intersecting a line drawn from the burr hole to a point between external auditory meatus(EOM) and 1cm posterior to EOM. Depth of catheter was 6-6.5cm. 2) hematoma at the middle portion of putamen ; Direction of catheter was the midpupillary line of the the eye and the point intersecting a line drawn from the burr hole to a point between 1cm and 2cm posterior to EOM. Depth of catheter was 6.5-7cm. 3) hematoma at the posterior portion of putamen ; Direction of catheter was 15 degree laterally from the midpupillary line of the eye and the point intersecting a line drawn from the burr hole to a point between 2cm and 3cm posterior to EOM. Depth of catheter was 7-7.5cm. We have performed FHA of putaminal hemorrhage in 48 cases according to this guideline. All catheter were inserted exactly at the center of hematoma and average operation time was about 30 minutes. Conclusion : Our proposed guidelines for putaminal hemorrhage are considered to be safe and simple method with similar accuracy and rapid decompression compared with traditional stereotactic method. Main advantages of this technique were unnecessity of stereotactic frame application and less time requirement for hematoma removal.

• Korean Security Journal
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• no.57
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• pp.85-110
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• 2018

The bodyguard is continuously training basic physical training and security art martial to protect the privacy of security target, prepare and deal with external contingencies and threats. Currently, university students majoring in security are required to take a judo class, one of their security art martial, which can use a technology to catch, crush and repress opponent. Therefore, this study identified the effects of systematic training on body composition, Performance fitness, growth hormones, and IGF-1 among male university students through a 10-week judo training program so that it was committed to providing objective data to enhance the value of judo as a security art martial and as a result, we have a conclusion as follows: After 10 weeks of judo training, muscle mass increased significantly, and body fat rate and BMI decreased significantly. The muscular strength and power of Performance fitness were shown to increase significantly, and growth hormones were shown to increase significantly. In total, the above results showed that for judo training university students, overall body composition improved positively, the muscular strength and power of active physical fitness improved, and growth hormones increased. Thus, the increase in muscle strength and growth hormones through judo training will encourage fat breakdown due to the development of the body's muscles and increase bone density in the spine, thereby reducing the risk of fractures and preventing injury to the trainees who are performing a security art martial. It will also greatly help your health by preventing obesity, cardiovascular and metabolic diseases, which eventually will enhance your bodyguard function and prolong your life as a bodyguard.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.574-583
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• 2021

Predicting shipping markets is an important issue. Such predictions form the basis for decisions on investment methods, fleet formation methods, freight rates, etc., which greatly affect the profits and survival of a company. To this end, in this study, we propose a shipping freight rate prediction model for container ships using gated recurrent units (GRUs) and long short-term memory structure. The target of our freight rate prediction is the China Container Freight Index (CCFI), and CCFI data from March 2003 to May 2020 were used for training. The CCFI after June 2020 was first predicted according to each model and then compared and analyzed with the actual CCFI. For the experimental model, a total of six models were designed according to the hyperparameter settings. Additionally, the ARIMA model was included in the experiment for performance comparison with the traditional analysis method. The optimal model was selected based on two evaluation methods. The first evaluation method selects the model with the smallest average value of the root mean square error (RMSE) obtained by repeating each model 10 times. The second method selects the model with the lowest RMSE in all experiments. The experimental results revealed not only the improved accuracy of the deep learning model compared to the traditional time series prediction model, ARIMA, but also the contribution in enhancing the risk management ability of freight fluctuations through deep learning models. On the contrary, in the event of sudden changes in freight owing to the effects of external factors such as the Covid-19 pandemic, the accuracy of the forecasting model reduced. The GRU1 model recorded the lowest RMSE (69.55, 49.35) in both evaluation methods, and it was selected as the optimal model.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.111-122
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• 2021

Objectives: There was a judgment of acquittal for the manufacturer SK Chemical and the vendor Aekyung regarding humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). The rationale used in this judgement is discussed here in the light of scientific consideration. Methods: The sentencing document for the judgements was obtained from the Korea Supreme Court Service. In particular, the judgements made by the court related to the risk of HD and external and internal exposure to CMIT/MIT are discussed based on scientific evidence. Results: Rendering a determination in a criminal trial of insufficient evidence of causation, the court dismissed the prosecution's motion that humidifier disinfectant-associated lung injuries (HDLI) and asthma were associated with the utilization of these products. However, CMIT/MIT, a strong sensitizing and corrosive substance, has been reported to be associated with brain toxicity, allergic contact dermatitis, and asthma. Furthermore, the judgment did not consider total consumption amounts or the cumulative dose of CMIT/MIT in the humidifier. Lastly, there are several cases supporting the fact that exposure to water-soluble substances including CMIT/MIT can cause lower respiratory tract diseases. In addition to cases of asthma among the workers exposed to CMIT/MIT, we identified lung injury victims who were exposed to HDs exclusively containing CMIT/MIT. Conclusions: We conclude that there is sufficient evidence supporting the assertion that HDs containing CMIT/MIT cause lung injuries, including asthma, contrary to the court's judgement.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.424-433
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• 2019

The purpose of this study was to investigate the effects of gender difference in injury experience on biomechanical variables of lower extremity during two leg drop landing. 20 male(injury experience=8, non-injury experience=12) and 20 female(injury experience=11, non-Injury Experience=9) in their 20's were selected as subjects. Two-way mixed ANOVA was performed on the biomechanical variables obtained from the two leg drop landing in a 45cm height box and post-test was performed with bonferroni adjustment(p <.05). The results of this study suggest that the group of female who injury experience could induce the reduction of the peak vertical ground reaction force by increasing the valgus and internal rotation of the knee joint and flexion and internal rotation of the hip joint. In the INE(injury non-experienced) female group, the peak knee flexion angle was the smallest, as well as the flexion of the hip joint and the external rotation angle, and the peak vertical ground reaction force was the highest. On the other hand, the INE female group showed high vertical ground reaction force because they did not utilize the knee and hip joints relatively than the IE(injury experienced) female group, this means that it is relatively exposed to the risk of injury. Therefore, it was found that gender difference in injury experience is a factor affecting factors of knee and hip joint movement and peak vertical GRF(ground reaction force).

• Journal of International Area Studies (JIAS)
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• v.19 no.1
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• pp.157-204
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• 2015

This paper explores firm-specific internal and external determinants of the sustainability of "the social innovative enterprise(SIE)" by conducting a case research on Fragrant People Co. In doing so, some business and policy implications have been produced concerning the components and determinants of the sustainability of the SIE. First, entrepreneurship is a necessary factor for the survival and growth of the SIE. A social entrepreneur does manage effectively social and economic opportunities for making economic and social values interact dynamically beyond their trade-off relationship and creating new market chances. Second, the SIE also needs competitive advantages as commercial enterprises do. Valuable resources to be used for taking opportunities and avoiding threats, rare resources not to be possessed by other firms, and resources not to be easily imitated by competitors are extremely necessary for achieving objectives of the SIE. In addition, a firm must be well organized for those valuable, rare, and not easily imitated resources. Economic performance achieved by the SIE gives a birth to its financial independence, contributing to the realization of symmetric social performance. Third, the SIEs will be allowed to seek symmetrically economic and social performance only when they use sufficiently competitive advantage resources with entrepreneurship, which is composed of innovativeness, proactiveness, agility and risk-taking attitudes. In doing so, financial assistance from central or local governments may not ensure the sustainability of the SIEs. In addition, vision & value sharing(person-organization fit) can ensure the sustainability of the SIEs only when it is connected with the organizational commitment.

• Journal of Life Science
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• v.29 no.3
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• pp.382-393
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• 2019

Wound care is a health industry concern affecting millions worldwide. Recent increase in metabolic disorders such as diabetes comes with elevated risk of wound-based complications. Treatment and management of wounds are difficult practices due to complexity of the wound healing process. Conventional wound dressings and treatment applications only provide limited benefits which are mainly aimed to keep wound protected from external factors. To improve wound care, recent developments make biopolymers to be of high interest and importance to researchers and medical practitioners. Biopolymers are polymers or natural origin produced by living organisms. They are credited to be highly biocompatible and biodegradable. Currently, studies reported biopolymers to exhibit various health beneficial properties such as antimicrobial, anti-inflammatory, hemostatic, cell proliferative and angiogenic activities which are crucial for effective wound management. Several biopolymers, namely chitosan, cellulose, collagen, hyaluronic acid and alginic acid have been already investigated and applied as wound dressing agents. Different derivatives of biopolymers have also been developed by cross-linking with other molecules, grafting with other polymers, and loading with bioactive agents or drugs which showed promising results towards wound healing without any undesired outcome such as scarring and physiological abnormalities. In this review, current applications of common biopolymers in wound treatment industry are highlighted to be a guide for further applications and studies.

• 한국사회정책
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• v.24 no.1
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• pp.67-95
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• 2017

This study compared policies of elderly abuse of long-term care facilities on WHO, Main countries for improvement of Korean policy. So, This study reviewed policies of elderly abuse of long-term care facilities on WHO, Main countries. So, This study reviewed risk factors that may increase the potential for abuse of an older person can be identified at individual level, care-woker levels, socio-cultural levels and facilities levels. The results of the study were as follows: First, The openness of long-term care facilities are emphasized on many countries. There are a need for a policy considerations such as policies of Ombudsman, Adult guardianship for visiting facilities, external monitoring. Second, There was a difference of facilities infrastructure and workers of treatment condition long-term care facilities each other countries. So It is important to improve facilities infrastructure and workers of treatment condition. Third, It is necessary to consider traits of elderly in long-term care facilities. Especially, it is required to manage dementia elderly and elderly on night time in long-term care facilities. Finally, implications and future directions of policies of elderly abuse of long-term care facilities were discussed based on the finding of the study.