• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.13-22
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• 2017

Objectives: The objective of this study was to evaluate the exposure levels of door-to-door deliverers to fine particulate matter (PM2.5). Another objective was to confirm the general working patterns of door-to-door deliverers via survey. Methods: In the city of Daegu, ten door-to-door deliverers who wished to join the study were recruited. The general working characteristics of door-to-door deliverers were surveyed using self-reported questionnaires. In the cabin of each car driven by a deliverer, a real-time PM2.5 sampler (Sidepak, Model AM510, TSI Inc., MN, USA) and a GPS device (GPS 741, Ascen, Korea) were installed. Each deliverer was monitored for four days per week so that each day could be monitored at least four times. Results: A total of 40 measurements of PM2.5 concentrations were taken during delivery of parcels. The average exposure levels of door-to-door deliverers to PM2.5 was $44.62{\mu}g/m^3$ ($7-9443{\mu}g/m^3$. Exposure levels to PM2.5 according to the day of the week and coverage areas were not significantly different (p>0.05). Door-to-door deliverers using trucks with older diesel engines manufactured before 2006 had significantly higher exposure levels to PM2.5 than in the case of trucks with diesel engines manufactured after 2006 (p<0.05). Many of the door-to-door deliverers reported the status of having windows open during the delivery task. During delivery services, the working hours spent in residential areas were higher than on roadsides, but exposure levels to PM2.5 in residential areas and on roadsides were $46.17{\mu}g/m^3$ and $49.90{\mu}g/m^3$, respectively. Real-time PM2.5 exposure levels were significantly different between roadways and residential areas (p<0.001). Conclusions: PM2.5 exposure levels of door-to-door deliverers were found to be affected by higher vehicle emissions from the roadsides near their vehicle during deliveries and while driving to other locations compared to by PM2.5 from the diesel engines of their own trucks. Particle concentrations from roadsides and emissions from nearby vehicles through open windows were the main source of PM2.5.

• The Journal of Internal Korean Medicine
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• v.30 no.1
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• pp.212-227
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• 2009

Objective : Membranous nephropathy (MN) is one of the most commonest forms of glomerular disease in man and the most frequent cause of the adult idiopathic nephrotic syndrome. Some investigators recommend no treatment, while others propose aggressive therapy, including prednisolone plus an immunosupressant such as chlorambucil or cyclophosphamide. But a more effective way to treat MN is not defined yet. This study was to evaluate the effects of Patriniae Radix extract (PRE) on the MN induced by cBSA in mice. Methods : Mice were divided into 4 groups. The first group (normal) was injected with saline. The second group (control) was treated with cBSA (10 mg/kg i.p) only. The third group, named PRE-2S0, was treated with cBSA (10 mg/kg i.p) and PRE (250 mg/kg, p.o). The fourth group, PRE-500, was treated with cBSA (10mg/kg i.p) and PRE (500mg/kg, p.o). After cBSA and PRE treatment for 4 weeks, we measured change of body weight, 24hrs proteinuria, serum albumin, total cholesterol, triglyceride, BUN, creatinine, IgG, IgA, IgM, $TNF-\alpha$, $IL-1\beta$, and $IFN-\gamma$ levels and the mRNA expression of $IFN-\gamma$, IL-6, and IL-10. The morphologic changes of renal glomeruli were also observed with a light microscope and an electron microscope. Results : The levels of 24 hrs proteinuria and serum triglyceride. BUN. IgG. $TNF-\alpha$, and $IL-1\beta$ significantly decreased in both PRE groups, while the level of serum albumin significantly increased in both PRE groups. The mRNA expression of IL-10 in splenocytes considerably increased in both PRE groups. The mRNA expression of $IFN-\gamma$ and IL-6 in splenocytes considerably increased in both PRE group. In histological findings of kidney tissue, thickening of GBM decreased in both PRE groups. Conclusions : The present study suggests that PRE is effective when treating mice with MN induced by cBSA. More clinical data and studies are to be done for efficient application.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.309-315
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• 2001

Objective : To develop a boner understanding of the relationship between weight status and the prevalence of obesity related diseases in the Korean population. Methods : The 1998 Korean National Health and Nutrition Survey was used and 10,880 persons who had previously taken health examinations were selected for study. The Korean Society for the Study of Obesity's classification of weight status was used. Hypertension, diabetes mellitus, dyslipidemia, osteoarthritis, chronic heart disease, stroke were included as obesity related disease. A logistic regression model was developed to estimate the prevalence odds ratio by obesity class adjusted for demographic and socioeconomic factors and we converted the odds ratio to a prevalence ratio using the base line prevalence of disease to aid in the interpretation of the ratios. Results : The prevalence of obesity was 26.3% based on the KSSO classification $(BMI\geq25)$. A graded increase in the prevalence ratio was observed with increasing severity of overweight and obesity for all health outcomes with the exception of chronic heart disease in men and stroke in both men and women. With normal weight individuals as the reference, for men who were younger than 50 years, the prevalence ratios were highest for hypertension BMI<23-25: 1.70(95% CI=1.41-2.05), 25$BMI\geq30$: 4.83(95% CI=3.70-5.84). The prevalence ratios for dyslipidemia were as high as hypertension, but were lower than hypertension for diabetes mellitus and osteoarthritis. Prevalence ratios generally were greater in younger adults. The prevalence of having 2 or more obesity related diseases increased with weight status category, except in people who were older than 50 years. Conclusions : Based on results, obesity is an increasingly important health problem in Korea and the disease burden increases according to weight status. For Korean adults, the strongest relationship was seen between weight status and hypertension and dyslipidemia. In older people the impact of excess weight and obesity is stronger than that seen in younger people. Increased efforts in the study of obesity and prevention and treatment of obesity and obesity related disease are required.

• Journal of Preventive Medicine and Public Health
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• v.33 no.4
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• pp.459-468
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• 2000

Objectives : To investigate the association between BMI and Mortality. Methods : This study was based on the analysis and assembly of the 'Kangwha Cohort Study', previously conducted by the Department of Preventive Medicine, Yonsei University. A total of 2,696 males and 3,595 females were followed for almost ten years and ten months from March 1985 to January 1996, a total of whom 2,420 died during this period. The Cox's proportional hazards regression model was used to analyze this data. Results : We found a U-shaped relationship between BMI and mortality among the aged men in the Kangwha cohort. The hazard ratio of dying was adjusted for age, marital status, occupation, self cognitive health level, chronic disease, smoking, and alcohol frequency, then sorted by body mass index into the following groups; less than 10.5, 18.5 to less than 21.0, 21.0 to less than 23.5, 23.5 to less than 26.0 and greater than or equal to 26. The corresponding ratios for men were 1.81(1.50-2.19, 95%CI), 1.31(1.14-1.51, 95%CI), 1.0(referent), 1.05(0.87-1.26, 95%CI) and 1.39(1.09-1.76, 95%CI), respectively. And for women, 1.46(1.19-1.78), 1.12(0.95-1.31, 95%CI), 1.0(referent), 1.00(0.84-1.20, 95%CI) and 1.09(0.89-1.34, 95%CI), respectively. Conclusions : The risk of death among aged men in Kangwha increased in the under and overweight groups. The relationship between BMl and mortality has been well studied in Western populations, but little is known about the association between BMI and mortality in our country. So, on the basis of this study, it is apparent that more studies of the relationship between BMI and mortality will be needed for future work.

• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.215-224
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• 1997

Gamijiyu-tang (GJT) described originally in the Dong Eui Bo Gam, a traditional reference for oriental medicine in the Korea, has been clinically used for treatment of chronic liver disease. In order to evaluate scientifcally a hepatoprotective effect of GJT in the liver fibrotic disease, the present study investigated how GJT improves a hepatic function in the dimethylnitrosamine (DMN)-treated rat. DMN treatment caused a significant increase of relative liver weight to the body at 28 days after DMN induction. Administration of with a clinical dose decreased significantly the sAST level $(158.8{\pm}7.76\;IU/L)$ elevated by DMN in jection (p<0.01). A similar phenomenon was also observed at change of both Salt and Salt level in the GJT and/or DMN-treated animal (p<0.01, p<0.05, respectively). A remarkable increase of hydroxyproline was observed by treatment of DMN with comparing to the normal rat $(361.9{\pm}7.35\;vs.\;1278.1{\pm}52.9\;{\mu}g/g\;tissue,\;p<0.01)$. This was significantly reduced by a simultaneous treatment of GJT with DMN for 21 days (p<0.05), but not recovered completely to its normal value. In addition. GJT administration ameliorated conspicuously the DMN-induces histopathological changes of liver such as hemorrhage. Cell necrosis and fibrosis. Tak'en together, results described here demonstrated scientifically in first the medicinal efficacy of GJT by using in vivo animal model, indicating that GJT improves the DMN-induced hepatic injury through reducing an excessive accumulation of collagen and histopathological changes. The decreased collagen content may be a pivotal process for GJT to improve hepatic function in the DMN-induced liver fibrosis. The present study suggests that GJT may be useful for and applicable to the treatment of hepatic fibrosis in chronic liver disease.

• Information Systems Review
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• v.17 no.3
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• pp.39-64
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• 2015

As information and information technology become more important in competitive corporate environments, the risk of information security breaches has increased accordingly. Although organizations establish security measures to manage information security risks, members of organizations do not comply with them well, and their information security behavior intention is unclear. Therefore, to understand the information security risk management intention of the members of organizations, the present study developed a research model using Protection Motivation Theory, Supervisory Authority Pressure, and Background factors. This study presents empirical research findings based on the analysis of survey data from 201 members of financial institutions. Perceived Severity, Self-efficacy, and Supervisory Authority Pressure had a positive effect on intention; however, Perceived Vulnerability and Response Efficacy did not affect intention. Security Avoidance Habit, which was considered a background factor, had a negative effect on all parameters, and did not have an effect on intention. Security Awareness Training, another background factor, had a positive effect on information security risk management intention and perceived vulnerability, self-efficacy, response efficacy, and supervisory authority pressure, and had no effect on perceived severity. This study used supervisory authority pressure and background factors in the field of information security, and provided a basis to use supervisory authority pressure in future studies on behavior of organizations and members of an organization. In addition, the use of various background factors presented the groundwork for the expansion of protection motivation theory. Furthermore, practitioners can use the study findings as a foundation for organization's security activities, and to improve regulations.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.31-39
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• 2014

Norovirus causes acute gastroenteritis in all age groups and its food poisoning outbreaks are rapidly increasing in Korea. Reverse transcription-polymerase chain reaction (RT-PCR) is most widely used for the rapid detection of foodborne viruses due to high sensitivity. However, the false positive results of RT-PCR obtained against already inactivated viruses could be a serious drawbacks in food safety area. In this study, we investigated a method to yield true positive RT-PCR results only with alive viruses. To decompose the RNA genes from dead viruses, the enzymatic treatments composed of proteinse K and Ribonuclease A were applied to the sanitized and inactivated virus particles. Another aim of this study was to quantify the efficiencies of several major sanitizing treatments using real-time RT-PCR. Feline calicivirus (FCV) that belongs to the same Caliciviridae family with norovirus was used as a surrogate model for norovirus. The initial level of virus in control suspension was approximately $10^4$ PFU/mL. Most of inactivated viruses treated with the enzymatic treatment for 30 min at $37^{\circ}C$ were not detected in RT-PCR, Quantification results to verify the inactivation efficiencies of sanitizing treatments using real-time RT-PCR showed no false positive in most cases. We could successfully develope a numerical quantification process for the inactivated viruses after major sanitizing treatments using real-time RT-PCR. The results obtained in this study could provide a novel basis of rapid virus quantification in food safety area.

• Economic and Environmental Geology
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• v.38 no.1
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• pp.67-78
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• 2005

Riverbank filtration has been used in advanced countries for 150 years. In Korea, investigations for producing riverbank filtrate started in the Han River, Nakdong River, Geum River, Yeongsan River and Seomjin River basins in the 1990s. The lower part of the Nakdong River has a poorer water quality than the upper part of the river. A water balance analysis and groundwater flow modeling were conducted for the riverbanks of the Nakdong River in Daesan-Myeon, Changwon City. The results of the water balance analysis revealed the groundwater infiltration rate into the aquifer to be 245.26 mm/year (19.68% of the average annual precipitation, 1,251.32 mm). Direct runoff accounts for 153.49 mm/year, evapotranspiration is 723.95 mm/year and baseflow is 127.63 mm/year. According to the groundwater flow modeling, 65% of the total inflow to the pumping wells originates from the Nakdong River, 13% originates from the aquifer in the rectilinear direction, and 22% originates from the aquifer in the parallel direction. The particle tracking model shows that a particle moving from the river toward the pumping wells travels 100 m in 50 days and a particle from the aquifer toward the pumping wells travels 100 m in 100 days.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.783-798
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• 2004

An e-business client application in ubiquitous mobile computing environment may become disconnected from the enterprise server due to broken communication connections caused by the limitation of mobile computing environments(limited battery life of the mobile device, low bandwidth communication, incomplete wireless communication infrastructure, etc). It Is even Possible that mobile client application Intentionally operates in disconnected mode to reduce communication cost and the power consumption of the mobile device. We use “data hoarding” as a means of providing local autonomy to allow transactions to be processed and committed on the mobile host despite of disconnection. The key problem to this approach is the synchronization problem that serialize potentially conflicting updates from disconnected clients on master objects of the server database. In this paper, we present a new transaction synchronizing method that splits a transaction into a set of independent component transactions and give the synchronization priority on each component taking the possibility of use and conflicts in the server into consideration. Synchronization is performed component by component based un synchronization priority. After the Preferred component of a no bile transaction succeeds in synchronization with the server, the mobile transaction can pre-commit at server. A pre-committed transaction's updated value is made visible at server before the final commit of the transaction. The synchronization of the component with low synchronization priority can be delayed in adaption to wireless bandwidth and computing resources. As a result, the availability of important data updated by mobile client is increased and it can maximize the utilization of the limited wireless bandwidth and computing resources.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.4
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• pp.503-508
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• 2010

Recently, the advance of mobile devices has made various services possible beyond simple communication. One of services is the predicting the future path of users and providing the most suitable location based service based on the prediction results. Almost of these prediction methods are based on previous path data. Thus, calculating similarities between current location information and the previous trajectories for path prediction is an important operation. The collected trajectory data have a huge amount of location information generally. These information needs the high computational cost for calculating similarities. For reducing computational cost, the meaningful location based trajectory model approaches are proposed. However, most of the previous researches are considering only the physical information such as stay time and the distance for extracting the meaningful locations. Thus, they will probably ignore the characteristics of users for meaningful location extraction. In this paper, we suggest a meaningful location extracting and trajectory simplification approach considering the stay time, distance, and additionally interaction information of user. The method collects the location information using GPS device and interaction information between the user and the others. Using these data, the proposed method defines the proximity of the people who are related with the user. The system extracts the meaningful locations based on the calculated proximities, stay time and distance. Using the selected meaningful locations the trajectories are simplified. For verifying the usability of the proposed method, we collect the behavioral data of smart phone users. Using these data, we measure the suitability of meaningful location extraction method, and the accuracy of prediction approach based on simplified trajectories. Following these result, we confirmed the usability of proposed method.