• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.451-458
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• 2022

In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2158-2165
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• 2023

Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm³ and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a ¹³⁷Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden ¹³⁷Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.4
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• pp.19-31
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• 2022

Purpose: This study was conducted to identify indoor air quality in various living spaces using sensors that can measure noise, vibration, fine dust, and odor in real time and to propose optimal indoor air quality maintenance management using Internet of Things(IoT). Research design, data and methodology: Using real-time sensors to monitor physical factors and environmental air pollutants that affect the comfort of the residential environment, Noise, Vibration, Atmospheric Pressure, Blue Light, Formaldehyde, Hydrogen Sulfide, Illumination, Temperature, Ozone, PM10, Aldehyde, Amine, LVOCs and TVOCs were measured. It were measured every 1 seconds from 4 offices and 4 stores on a small scale from November 2018 to January 2019. Results: The difference between illuminance and blue light for each measuring point was found to depend on lighting time, and the ratio of blue light in total illumination was 0.358 ~ 0.393. Formaldehyde and hydrogen sulphide were found to be higher than those that temporarily attract people in an indoor office space that is constantly active, requiring office air ventilation. The noise was found to be 50dB higher than the office WHO recommendation noise level of 35 ~ 40dB. The most important factors for indoor environmental quality were temperature> humidity> illumination> blue light in turn. Conclusions: Various factors that determine the comfort of indoor living space can be measured with real-time sensors. Further, it is judged that the use of IoT can help maintain indoor air quality comfortably.

• Journal of the Korean Society of Food Culture
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• v.24 no.4
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• pp.385-390
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• 2009

This study was conducted to develop the unique native local foods of Namwon and to provide basic data needed to reinvigoratethe tourist industry and local economy. Perception and satisfaction with native local foods of Namwon were surveyed in 483 tourists (246 men and 237 women 53% visiting Namwon for the first time). Of the participants, 41.2% did not stay or eat in Namwon. Most tourists visited with other family members and spent approximately 20,000 won per capita on food. Of the foods sampled for the first time, preferred foods were (in order of preference and intention to order again) Chueo-tang, Hanjeongsik, wild edible greens-jeongsik, and black pork. The degree of food satisfaction was relatively favorable (3.54${\pm}$0.08 points on a 5-point satisfaction scale), with taste being the most important factor affecting the degree of satisfaction for 92.9% of the subjects. However, willingness to revisit Namwon on the basis of the local foods was not as high as the degree of satisfaction with the foods. Insufficient information and publicity concerning Namwon local foods were cited as impediments, and suggested improvements included taste, sanitation and food-based tourism. The degree of satisfaction was higher in men than in women. Age, residence, and occupation were not related to the degree of satisfaction. But, the willingness to revisit Namwon to sample local foods was related with gender (men more willing) and occupation (public service personnel, business owners, salaried employees, professionals, and housewives more willing, in order). Women in general and housewives in particular were most critical in food assessment.

• Journal of the Korean Society of Food Culture
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• v.25 no.2
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• pp.150-159
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• 2010

We surveyed 848 university students, $21.4{\pm}2.5$ years of age, attending university in Seoul, Kongju, Chongyang-Gun in the Chungnam province of Korea, for their use of health functional foods (HFF) and for significant variables in this use, namely demographic characteristics, health related variables, dietary variables and nutritional beliefs. The prevalence of the use of HFF was 33.6%. Among all types of HFF, nutritional supplements were taken most frequently, followed by (in order) red ginseng products, apricot extract products and ginseng products. HFF use was higher in females (p<.05), in subjects living in a dormitory (p<.05) and those from families with a relative high socioeconomic status (p<.001). Self-health concern (p<.05) and usage ratio of HFF by family (p<.001) was higher in users than in nonusers of HFF. The total score of dietary assessment was higher in users than in nonusers of HFF (p<.001), and users had a more positive point of view concerning the potential health benefits of HFF than did nonusers (p<.001). Most users took HFF when they were healthy (37.2%) or when they were sick (27.4%). They did not feel special effects through the HFF use (49.8%). Most users got the information about the specifics of HFF from family and/or relatives (55.8%). Most of users confirmed nutrition facts when they purchased the HFF (70.9%), but a considerable number of users could not understand these nutrition facts (48.1%). Users preferred vitamin C- and Ca-supplements most among vitamin mineral supplements belonged to HFF. These results show that the use of HFF is common among university students. As well, the use of HFF by students is affected by various variables. Supplementary nutritional education should be undertaken among university students, in order to give them a reasonable guideline for the use of HFF, based upon influencing factors and usage behaviors that we learned from this survey.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.969-975
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• 2005

Purpose : We performed a study of clinical findings of Mycoplasma Pneumonia in children, to know differences between recent clinical manifestations of Mycoplasma pneumonia and previous studies. Methods : The subjects of this study were 393 children who were diagnosed as Mycoplasma pneumonia with high titers of Mycoplasma antibody(${\geq}1$ : 160) or fourfold rises of Mycoplasma antibody at Chung Ang University Hospital from January 1998 to December 2003. We practiced a retrospective study on the clinical manifestations of Mycoplasma pneumonia based on their medical records. Results : Male to female ratio was 1.06 to 1 and mean age was $4.32{\pm}2.94years$. The highest incidence was in the age of 2 to 3 years(18.6 percent). Most frequent months were October, and November in 2000, April in 2002, and October and, December in 2003. Twenty six point seven percent showed allergic diseases. Second degree relatives of 10.7 percent patients had allergic diseases. Forty three point three percent were admitted before this admission for pneumonia. Allergic tests were positive in 65.7 percent. Cough, and sputum were the most common symptoms and abdominal pain, and vomiting were the most frequent extrapulmonary symptoms. Atelectasis and pleural effusion were seen in 2.5 percent and 1.8 percent. Infiltrations were more common on the right side. Titers of each simultaneous test for cold agglutinin and mycoplasma antibody were not in proportion to each other (P=0.163). Conclusion : The onset age of mycoplasma pneumonia was found to be lower than it used to be. More patients had a past medical history or a family history of allergic disease, and more wheezing was heard and associated with recurrent pneumonia.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.2
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• pp.213-225
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• 1999

Objectives : The purpose of this study was to investigate how the play habits, temperament, and environmental factors might affect childhood obesity. Methods : Two hundred sixty children, aged 4 through 6 years living in Seoul & Cheonan were surveyed by a questionnaire about the children's play habit and the parent's related factors such as weight, height, education, income. In addition the Korean version of the Parent Temperament Questionnaire for Children and the Korean version of the Family Environment Scale were also administered to parents of those children. The height and weight of those children were measured and the percentage of body fat was measured by Bioelectrical Impedance Fatness Analyzer. Result : 1) Among 260 children, 25 children were considered to be obese on the basis of both obesity index and percentage of body fat. 2) Parents of obese children showed a significantly higher educational level(p<0.05) and mothers of obese children had significantly more jobs(p<0.05) and showed higher body mass index(p<0.05) than those of nonobese children. 3) By observing play habits of children, obese children spent significantly longer time in watching TV and video(p<0.05), while nonobese children showed a trend to play outside(p<0.1). 4) On the Korean version of the Parent Temperament Questionnaire for Children, obese children showed significantly less activity than nonobese ones(p <0.05). 5) Family of obese children had significantly higher point on subscale of Achievement orientation, Intellectual-cultural orientation and Moral-religious emphasis of the Korean version of the Family Environment Scale(p<0.05). 6) Percentage of body fat of obese children was correlated with children's watching TV time, activity level, scores of Achievement orientation, Intellectual-cultural orientation of the Korean version of the Family Environment Scale and the both parent's education levels(p<0.05). Conclusion : Obese children showed hypoactivity and more watching TV time. And obese children's both parent had higher educational level and their mother had higher Body Mass Index and more jobs. Family of obese children had higher point on items of Achievement orientation, Intellectual-cultural orientation and Moral-religious emphasis. Family environmental factors influence on children's obesity through interaction of genetic and behavioral-psychological factors concomittently.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.133-140
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• 2005

Purpose : This test is designed to identify the validity of treatment plan by implementing real-time dosimetry by means of dose that is absorbed into PTV and OAR when preparing doses of 3D and POP plans. Materials and Methods : In treatment. error can be calculated be comparing Exp. Dose with the actual dose, which has been converted from 'the reading value obtained by placing diode detector on the area to be measured'. Same test can be repeated using Alderson-Rando phantom. Results : Errors were found: A patient(POP plan): 197.6/199=-1.2%, B patient(3D-plan): 199.9/198.7=+0.6%, C patient: 196/200=-1.5%. In addition, considering the resulted value of measuring OAR besides target-dose for C patient showed 96/200, representing does of 47%, the purpose of protection was judged to be duly accomplished. Also it was acknowledged the resulted value of -3.7% met the targeted dose within the range of ${\pm}5%$. Conclusion : Aimed for identifying the usefulness of pre-treatment dose measurement using diode detector, this test was useful to evaluate the validity of curing because it resulted in the identification of category to be protected as well as t dose. Moreover, it is thought to have great advantage in ascertaining the dose of target, dose of which is not calculated yet. Similar to L-gram before treatment, this test is thought to be very effective so that it can bring great advantages in the aspects such as validity of curing method and post-treatment plan as well.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.105-111
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• 2007

Correlation between occlusal contact pattern and TMD have been hypothesized and partially investigated but results are controversial and not conclusive. The purposes of this study were to compare right-to-left difference of occlusal contact pattern, through contact points, contact force and occlusal balance, in the patients with unilateral TMD and also to evaluate its change related with TMD treatment. 36 patients with unilateral TMD from Department of Oral Medicine in Dankook University Dental Hospital were selected in this study (M:F=7:29, mean age of $29.2{\pm}14.8$ years). A computerized T-Scan II system (Tekscan, INC., USA) was employed for occlusal analysis and the simultaneity and occlusal balance through the number of tooth contact and magnitude of contact force were determined before and after TMD treatment. The number of contact points and contact force was more on the unaffected side than the affected side before treatment (p=0.056 and p=0.060, respectively) while significant difference between both sides was not found after treatment. The number of contact points and contact force on the affected sides significantly increased after treatment (p=0.038 and p=0.052), but the unaffected sides exhibited no significant difference between before and after treatment. In addition, sides difference in relative contact force decreased from about 27% to about 12% after TMD treatment (p=0.001). According to the results of this study, it is likely that unilateral TMD impairs right-to-left occlusal balance and that conservative TMD treatment alleviates the imbalance, subsequently leading to more symmetrical occlusal condition with increased contact points and force.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.25-28
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• 2012

Purpose : It is important to reduce radiation dose associated with computed tomography (CT) scanning to as low as reasonably achievable (ALARA). With Dose Modulation Technic, user select a desired image quality and the system adapts tube current to obtain the desired image quality with greater radiation dose efficiency. In this paper, we presents a comprehensive description of fundamentals, clinical applications and radiation dose benefits of Dose Modulation Technic depending on Body Mass Index(BMI). Materials and Methods : In this study, 149 patients were examined(The mean age : $58{\pm}12.4$ years old). Biograph True Point 40 (Siemens, USA) and Gemini TF 64 (Philips. Cleveland) were used for equipment. When we used Care Dose 4D (Siemens, USA) and D-dom (Philips, Cleveland), we measured dose reduction and Computed Tomography Dose Index (CTDI) depending on BMI. Then we analyze data using SPSS Ver.18. Results : When we used Care Dose 4D, p-value is considered statistically significant by groups with the result that we compared Care Dose 4D with D-dom. On the other hand, p-value isn't considered statistically significant by groups using D-dom. Conclusion : Dose modulation based on the projection angle didn't affect degree of obesity. And When using Care Dose 4D, dose reduction rate in the normal patients were higher than the obese. In this study, there are errors on somato type. So I think more research have to be done. Then application of Dose Modulation technic can help in maintaining acceptable image quality while reducing radiation dose by 20-60% in most instances.