• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.203-212
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• 2019

Objective: A total of five students at same middle school were reported to be diagnosed with pediatric leukemia (n=2), non-Hodgkin's lymphoma (NHL, n=1) and aplastic anemia (n=2) between 2016 and 2017. The aims of this study are to assess exposure to environmental hazardous agents known to be associated with the risk of leukemia and to examine whether the environment of school is associated with the risk leukemia. Method: A total of 11 environmental agents causing childhood leukemia were monitored using international certified method in schools where patients had ever attended. Radon & Thoron detector was used to monitor real-time airborne radon and thoron level ($Bq/m^3$). Clinician interviewed two among nine patients who agreed to participate in this study in order to examine the association of demographic and genetic factors by individually. Leukemia, NHL, and aplastic anemia were grouped into lymphohematopoietic disorder (LHP). Results: Except for airborne radon level, no environmental agents in school and household where patients may be exposed were found to higher than recommended airborne level. Clinical investigation found no individual factors that may be associated with the risk of LHP. Higher airborne radon level than Korea EPA's airborne radon criteria ($148Bq/m^3$) was monitored at most of several after-class room of one elementary school, where two leukemia patients graduated. Significant radon level was not monitored at class-room. Significant exposure to radon of patients was not estimated based on time-activity pattern. Conclusions: Our results have concluded that there have been no environmental factors in school and household environment that may be associated the risk of LHP.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.745-753
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• 2018

As the radiation is used in various fields, the number of radiation workers is on the increase and there has been an increasa in interest in the radiation worker's safety. In South Korea, it is focusing on securing safety of workers through KISOE system and owner's report. In advance study, We determined that in assessing the risks of securing safety for workers and businesses, the assessment of other items as well as exposure doses would be effective and develops the Radial Scale Analysis Model. So, data from the actual radiographic testing companies were applied to the radial scale analysis model to determine the risks of the actual companies. And, we selected 4 companies to confirm the applicability. Risk assessments of all 56 companies were conducted and improvements and inspections were anticipated for each company's problems. The results of the study are expected to be utilized by radiographic testing companies and regulatory for self-assessment and regulation criteria.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.193-204
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• 2021

Objectives: In January 2021, the former heads of the manufacturer SK Chemical and the vendor Aekyung were acquitted for manufacturing and selling humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). In this article, we analyzed the rationale used in this judgement 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 toxicological and individual association with HD perspectives were discussed based on scientific evidence. Results: The ruling stated that the necessary conditions for causality between CMIT/MIT and such diseases were not met based on the fact that asthma and lung damage were not found in the inhalation exposure animal experiments. The judgment overlooked the inevitable limitations of using animal experiments for verifying health effects in humans, which are often inconsistent with the observations in animals. Among 11 governmentaffirmed lung injury cases with CMIT/MIT usage, three patients' humidifier disinfectant-associated lung injury (HDLI) pathology proved that CMIT/MIT could cause lung injury similar to that caused by PHMG and PGH. In addition, five children showed decreased lung function related to damage caused by humidifier disinfectant exposure. 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 decision.

• Journal of Climate Change Research
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• v.2 no.1
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• pp.43-54
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• 2011

Recently, due to severe rainfall by the global climate change, natural disasters such as landslide had also been increased rapidly all over the world. Therefore, it has been very necessary to assess vulnerability of landslide and prepare adaptation measures to future climate change. In this study, we employed sensitivity, exposure and adaptative capacity as criteria for assessing the vulnerability of landslide due to climate change. Spatial database for the criteria was constructed using GIS technology. And vulnerability maps on the entire Korea of past and future were made based on the database. As a result, highly vulnerable area for landslide was detected in most area of Gangwon-do, the east of Gyeonggi-do, and southeast of Jeollanam-do, and the southwest of Gyeongsangnam-do. The result of landslide vulnerability depends on time shows that degree of very low class and low class were decreased and degree of moderate, high, and very high were increase from past to the future. Especially, these three classes above low class were significantly increased in the result of far future.

• Structural Engineering and Mechanics
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• v.32 no.3
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• pp.429-445
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• 2009

Thermal stability of quasi-isotropic composite and polymeric structures is considered one of the most important criteria in predicting life span of building structures. The outdoor applications of these structures have raised some legitimate concerns about their durability including moisture resistance and thermal stability. Exposure of such quasi-isotropic composite/polymeric structures to various and severe climatic conditions such as heat flux and frigid climate would change the material behavior and thermal viability and may lead to the degradation of material properties and building durability. This paper presents an analytical model for the generalized problem. This model accommodates the non-linearity and the non-homogeneity of the internal heat generated within the structure and the changes, modification to the material constants, and the structural size. The paper also investigates the effect of the incorporation of the temperature and/or material constant sensitive internal heat generation with four encountered climatic conditions on thermal stability of infinite cylindrical quasi-isotropic composite/polymeric structures. This can eventually result in the failure of such structures. Detailed critical analyses for four case studies which consider the population of the internal heat generation, cylindrical size, material constants, and four different climatic conditions are carried out. For each case of the proposed boundary conditions, the critical thermal stability parameter is determined. The results of this paper indicate that the thermal stability parameter is critically dependent on the cylinder size, material constants/selection, the convective heat transfer coefficient, subjected heat flux and other constants accrued from the structure environment.

• Safety and Health at Work
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• v.6 no.2
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• pp.134-138
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• 2015

Background: Noise-induced hearing loss (NIHL) is a major preventable occupational health problem with 250 million people worldwide known to have disabling impairment of moderate to greater severity. The aims of the study are to estimate the prevalence of NIHL in the police force; and study its association with age, sex, duration of service (years), smoking and alcohol habits, use of hearing protective devices, as well as preexisting chronic diseases. Methods: A cross-sectional study was conducted on 543 police personnel who had undergone periodic medical examination over a 12-month period. The diagnostic criteria for NIHL were (1) history of occupational noise exposure, (2) bilateral hearing loss, (3) hearing loss of ${\geq}25dBA$ at 4,000 Hz in two consecutive audiograms, and (4) no significant medical history affecting hearing. Severity of NIHL was based on the World Health Organization grading. Results: Males (74.8%) made up the majority of the police force. The mean age for police personnel was $35.55{\pm}9.57years$, and the mean duration of service was $14.75{\pm}9.39years$. Compliance with the usage of hearing protective devices was seen in 64.4%. The prevalence of NIHL in this study population was 34.2%, with a higher prevalence in males (37.7%) than in females (23.9%). The study also showed strong associations between NIHL and male sex (odds ratio, 1.9; P < 0.05), and hypertension (odds ratio, 3.3; P < 0.001). Overall, 93% were found to have mild NIHL, 3.5% had moderate NIHL, and 3.5% had severe NIHL. No police personnel were found to have profound hearing loss. Conclusion: The prevalence of NIHL in this study is high compared to other similar studies among police personnel. This study shows that increasing age, male, presence of hypertension, diabetes, and longer duration of service are significant associated factors for NIHL. Preventative strategies include health surveillance, implementation of a hearing conservation program, and legislation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2309-2315
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• 2013

VANET(Vehicular Ad-hoc Network) is getting attention as an application to improve driver safety through inter-vehicle communication. For activation of VANET, privacy-preserving mutual authentication has to be guaranteed. In previous works, authors proposed various group-based authentication protocols. However, risks on ID exposure due to repeated use of group key and RSU(Road Side Unit) DoS attack were not considered. In this paper, we propose a probabilistic approach for robust anonymous authentication protocol. We evaluated our proposed method in a sets of criteria in VANET and verified it is an efficient solution for enhancing privacy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.3
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• pp.91-101
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• 2011

Internet is becoming increasingly popular due to the rapid development of information and communication technology. There has been a convenient social activities such as the mutual exchange of information, e-commerce, internet banking, etc. through cyberspace on a computer. However, by using the convenience of the internet, the personal IDs(identity card, driving license, passport, student ID, etc.) represented by the electronic media are exposed on the internet frequently. Therefore, this study propose a feature extraction method to analyze the characteristics of image files containing personal information and a image retrieval method to find the images using the extracted features. The proposed method selects the feature information from color, texture, and shape of the images, and the images as searched by similarity analysis between feature information. The result which it experiments from the image which it acquires from the web-based image DB and correct image retrieval rate is 89%, the computing time per frame is 0.17 seconds. The proposed method can be efficiently apply a system to search the image files containing personal information and to determine the criteria of exposure of personal information.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.381-387
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• 2005

Malignant hyperthermia is a catastrophic, hypermetabolic syndrome that arises in susceptible individuals when they are exposed to certain inhalational anesthetics or muscle relaxants. It is characterized by hyperthermia, tachycardia, acidosis, and muscle rigidity. It has been noted that the majority of cases of malignant hyperthermia are fatal unless early diagnosis and treatment are performed. We experienced a 24 year old male Malignant hyperthermia presented for orthognathic surgery under $O_2-N_2O$-sevoflurane anesthesia without succinylcholine. Two half hours after induction, tachycardia developed and was followed by unstable blood pressure and hyperpyrexia. Anesthesia was terminated and vigorous emergency treatment was attempted. The patient was treated by the intravenous administration of dantrolene sodium. The diagnosis of an acute malignant hyperthermia reaction by clinical criteria can be difficult because of the nonspecific nature and variable incidence of many of the clinical signs and laboratory findings. So the malignant hyperthermia clinical grading scale is recommended for use as an aid to the objective definition of this disease. This clinical grading system provides a new and comprehensive clinical case definition for the malignant hyperthermia syndrome. We recently encountered a case of delayed malignant hyperthermia during sevoflurane anesthesia that was successfully treated by the intravenous administration of dantrolene sodium. In conclusion, exposure to sevoflurane should be avoided in patients thought to be susceprible to malignant hyperthermia.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5817-5821
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• 2012

Background/Aims: Glutathione S-transferase M1 (GSTM1) is a multifunctional enzyme that plays a critical role in the detoxification of varieties of carcinogenic metabolites. Many studies have been conducted to investigate the association between GSTM1 polymorphism and nasopharyngeal cancer (NPC) risk, but the findings among those studies are inconsistent. To assess this relationship more precisely, we performed a meta-analysis of all available studies on the subject. Methods: Case-control studies were identified by searching Pubmed, Embase, ISI Web of Science, and Wanfang databases through September 6, 2012. We used the pooled odds ratio (OR) with its corresponding 95% confidence interval (95%CI) to evaluate the association of GSTM1 polymorphism with NPC susceptibility. Subgroup analyses by pathological types, sex and smoking status were performed to further identify the association. Results: Overall, 11 published studies with 1,513 cases and 2,802 controls were finally included into this meta-analysis according to the inclusion criteria. Meta-analysis of total studies showed that the null genotype of GSTM1 was significantly associated with increased risk of NPC, when comparing with the non-null genotype (OR=1.51, 95%CI=1.33-1.72, POR<0.001). The association was still statistically significant in subgroup analysis of patients with nasopharyngeal squamous cell carcinoma (OR=1.73, 95%CI=1.24-2.42, POR=0.001). Males with the null genotype of GSTM1 were more likely to subject to NPC than females. In addition, the association between the null genotype of GSTM1 and NPC risk was strongest in individuals with exposure to smoking. Sensitivity analysis by sequential omission of any individual studies one at a time further demonstrated the significant association. Conclusions: The findings suggest that the null genotype of GSTM1 is a risk factor for NPC, and there is a gene-smoking interaction in this association.