• Progress in Medical Physics
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• v.20 no.3
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• pp.174-179
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• 2009

To track moving tumor in real time, CyberKnife system imports a technique of the synchrony respiratory tracking system. The fiducial marker which are detectable in X-ray images were demand in CyberKnife Robotic radiosurgery system. It issued as reference markers to locate and track tumor location during patient alignment and treatment delivery. Fiducial marker implantation is an invasive surgical operation that carries a relatively high risk of pneumothorax. Most recently, it was developed a direct lung tumor registration method that does not require the use of fiducials. The purpose of this study is to measure the accuracy of target applying X-sight lung tracking using the Gafchromic film in dynamic moving thorax phantom. The X-sight Lung Tracking quality assurance motion phantom simulates simple respiratory motion of a lung tumor and provides Gafchromic dosimetry film-based test capability at locations inside the phantom corresponding to a typical lung tumor. The total average error for the X-sight Lung Tracking System with a moving target was $0.85{\pm}0.22$ mm. The results were considered reliable and applicable for lung tumor treatment in CyberKnife radiosurgery system. Clinically, breathing patterns of patients may vary during radiation therapy. Therefore, additional studies with a set real patient data are necessary to evaluate the target accuracy for the X-sight Lung Tracking system.

• Journal of Oriental Neuropsychiatry
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• v.26 no.3
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• pp.225-234
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• 2015

Objectives: We aimed to evaluate the use of Korean medicine in patients with dizziness or vertigo, since such study has not been performed previously. Methods: In the current study, we included 3 diagnoses i.e., Disorders of vestibular function (H81), Vertiginous syndromes in diseases classified elsewhere (H82), and Dizziness and giddiness (R42) from the Health Insurance Review and Assessment Service (HIRAS) database for 4 years. We analyzed the database and compared treatment with Korean vs. Western medicine. Results: 1. Korean medical visits and cost have been increasing for 4 years, except 2011. Western medical visits are 11.9 times higher than Korean medical visits. 2. The number of women who received Korean medicine was 2.6 times higher than that of men. 3. Among all ages, the 70~79 years group were the most frequent users of Korean medicine. The older age was correlated with more patients' visits. 4. The comparative number of visits by patient care type for 4 years indicated that outpatients had more visits than hospitalization. Furthermore, outpatient visits have been increasing for 4 years. 5. The comparative number of visits by hospital type for 4 years indicated that visits to the Korean medical clinic were the highest. In primary care, patients used more Korean medicine than Western medicine. In tertiary care, patients used more Western medicine than Korean medicine. 6. Korean medical cost per patient by patient care type for 4 years was a total 89,000 won, hospitalization 449,000 won and outpatient 83,000 won. Costs of all patient care types have been increasing. 7. Korean medical cost per patient by hospital type for 4 years was 156,000 won for Korean medical hospital, 83,000 won for local clinic and 127,000 won for miscellaneous facilities. Costs of all types have been increasing. Conclusions: This study provided objective information about epidemiologic characteristics of Korean medicine in patients with dizziness or vertigo. Furthermore, it provides an understanding of the recent status and forms the basis for further expansion of demand for Korean medicine among patients with dizziness or vertigo.

• Journal of Life Science
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• v.27 no.3
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• pp.334-338
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• 2017

In this study, the nutritional components of Tenebrio molitor, Protaetia brevitarsis, and Allomyrina dichotoma larvae, which have been registered as novel foods, were analyzed and compared to expand the diversity of selection criteria for edible insects. The contents of crude components, amino acids, fatty acids, and minerals were analyzed. According to the results of comparative analysis of edible insects, crude proteins were abundant in all three kinds of insects. The content of crude fat was the highest in T. molitor, and the content of carbohydrate was the highest in A. dichotoma. When comparing the composition of amino acids, total amino acid content and essential amino acids were the highest in T. molitor larvae. In T. molitor and P. brevitarsis larvae, the compositions of fatty acids were similar, with higher amounts of unsaturated fatty acids than in A. dichotoma. In terms of mineral content, A. dichotoma contained the highest amounts of calcium and iron, whereas P. brevitarsis contained the highest amounts of phosphorus and potassium. With these results, it is expected that edible insects could be selected according to nutritional demand. In addition, multiple combinations of edible insects will offer a richer intake of nutrients.

• Therapeutic Science for Rehabilitation
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• v.9 no.3
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• pp.23-34
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• 2020

Objective : Recently, the demand for wearable mobile devices for the monitoring and improvement of one's health and quality of life is increasing. Therefore, the purpose of this study is to analyze the need of potential users in order to develop mobile health based and lifestyle care application for the elderly. Methods : Participants who lived in their community and used a mobile phone were recruited. Finally, a total of 84 participants completed the survey. Data were analyzed using descriptive statistics and a t-test, which was carried out with SPSS version 25.0. Results : The application functions that users deemed important for a lifestyle care app were the number of daily steps, physical activity, blood pressure, sleep, nutrition and participation in activity. Interestingly, there was a significant difference in the importance given to the app function of participation in activities between age groups. Conclusion : This study investigated the need and preferences of potential users of health and lifestyle care application for the promotion of health among the elderly. The, findings obtained from this study could be a valuable resource for the development of lifestyle care application.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.503-510
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• 2007

The purposes of the study were to analyze the seasonal effects on the fish fauna and compositions including trophic guilds and tolerance guilds. For the study, we collected fish samples twice in June as premonsoon period and early September 2007 as monsoon periods in five sampling sites of the Gap Stream, and then biological oxygen demand (BOD), nutrients (TN, TP) and suspended solids (SS) were compared with the guild data along the gradient of upstream-to-downstream. Chemical water quality, based on BOD, TP, and TN degraded gradually from the upstream to downstream reach and there were about 3 fold difference between S1 and S5. Water quality was worse in the premonsoon than the monsoon, and the heavy monsoon resulted in a dilution of the polluted river by rain water, especially, in the downstream reach. Total number of fish species, based on the catch per unit effort (CPUE), showed a distinct difference between the two seasons; 30 species were sampled in premonsoon, but 23 species were sampled in the monsoon, indicating a seasonal difference in the fish fauna. Tolerant species dominated the fish community (48.3%) in the stream, and the proportions prior to physical disturbance by the monsoon rain were evidently greater in the downstream reach than the upstream. This reflected the characteristics of urban stream polluted by nutrient enrichment as shown in the BOD and TP values. Sensitive species in the premonsoon decreased from the gradient of upstream-to-downstream reach. Such seasonal modifications in the trophic and tolerance guilds were evident. In the analysis of trophic guild and habitat guild, during the premonsoon the proportion of insectivore and riffle-benthic species were largely greater in the upstream reach than the downstream, whereas the proportions were opposite along the gradient of the stream in monsoon. Thus, the patterns of chemical water quality along the longitudinal gradients reflected the premonsoon conditions of insectivores and tolerant species, indicating that summer monsoon data of fish may not match with water quality due to large physical disturbance by flow regime. Seasonal monsoon in this region as well as the chemical pollution may act as a key role influencing the fish compositions of trophic and tolerance guilds and fauna. The data collected during the premonsoon rather than the monsoon, thus, may be better predictor for a diagnosis of stream health conditions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.401-417
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• 2020

As an increasing demand for rapid railway transportation, the construction of sidetrack is inevitable to operate local and express trains simultaneously. However, the current technologies for the sidetrack construction method require a long construction period by interrupting the operation of the existing subway line, as well as cause a huge economic loss. Thus, it is necessary to study the sidetrack construction method under the special situation that the subway is in operation and to analyze the risk of the existing tunnel enlargement process for the sidetrack construction. Therefore, in this paper, the Government Complex Gwacheon station on Subway Line 4 was considered as a target station for the virtual sidetrack construction and the optimal sidetrack construction plan was derived. Subsequently, the application of risk management process was carried out in the order of identifying risk, risk response planning, performing a risk analysis, risk monitoring and control for potential risk events during the construction of sidetrack under the subway operation. A total of eight potential risk events and risk mitigation methods were selected, and a risk assessment matrix was established using the five-step risk probability and impact level criteria to perform the risk assessment including residual risks. Based on the results of the risk assessment, the risk grade and the reduction effect of each risk mitigation method were confirmed.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.51-64
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• 2014

Small and medium Enterprises (SMEs), which have a manufacturing method of small quantity batch production produce goods using a general-purpose equipment and attached auxiliary tools. Many previous studies have focused on finding the effective resource allocations for improving the firms' productivity. It is very important for SMEs to keep costs low in assigning jobs to each resource, because they should meet the future uncertain demand of consumers under the limited budget. Using the concept of salvage cost, this paper proposes how to effectively allocate the tasks to main resources in the production process. The salvage cost is defined that purchasing cost minus decrease in value by workload, the method considering this is expected to reduce total purchasing costs during business period. To validate the effect of the proposed method, we proceed the real case study targeting on S company, PCB manufacturer to compare purchase amounts and its costs between the allocation proposed based salvage cost and current allocation method of current S company. As a results, In short-term (3 year) business period, salvage allocation have remarkable superior outcome to existing method, but gradually have cancelled out the effects in long-term (8 year) plans. Unlike the cycle allocation method, there exists the idle-equipments in allocation based salvage value. we additionally analyze the profits with respect to rental strategy of them during business period.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.13-18
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• 2009

We confirmed methane production and reduction of pollution during anaerobic digestion of milk waste and analyzed the economic potential of using milk waste as a renewable energy source. The milk waste sludge was obtained from the Pasteur milk factory and processed by anaerobic digestion to produce methane. The methane production from two completely mixed tank reactors with an effective capacity of 6 ${\ell}$, 15 days of hydraulic retention time (HRT), and a mid-temperature of $35^{\circ}C$ averaged 4.11 ${\ell}$/day. The total chemical oxygen demand (TCOD) during production decreased from an initial 31,416 mg/${\ell}$ to 13,500 mg/${\ell}$, showing a maximum TCOD removal efficiency of 60%. When HRT was reduced to 12 days, methane production increased by 44% under a high-temperature condition of $55^{\circ}C$. An economic analysis based on these results was applied to a Korean milk factory of typical size and demonstrated that the installation of an anaerobic digester could provide sufficient economic profit.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.204-216
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• 2019

To evaluate the biological integrity of aquatic ecosystems, we developed Korean multimetric diatom index (KMDI) using metrics that many researchers have been previously described, and compared to single-metric diatom index such as trophic diatom index (TDI) and diatom assemblage index to organic pollution (DAIpo). For the biological and environmental data, we investigated the epilithic diatoms, water quality and the land-use for 923 sites in Korean streams between 2013-2017, and estuaries between 2010-2017, respectively. Five appropriate metrics were selected according to the following steps; 1) extraction of 300 potential metrics (biological, chemical, physical, and geographical) based on previous references, of these, 2) 46 samples having high separation power were selected, 3) the selected metrics were each tested for variability, redundancy, and sensitivity to the environments, finally 4) construction of multi-metric diatom index comprising single type metrics such as TDI, DAIpo, % motile diatoms, % Achnanthes / (Achnanthes+Navicula), and % number of Gomphonema species. The biological integrity of the 233 sites from the Geum River basin were independently investigated using KMDI. Collectively, the new KMDI showed high sensitivity and explanatory power for environmental factors such as land-use, biochemical oxygen demand, total nitrogen, and electric conductivity. However, it had slightly higher biological integrity for the same sites as compared to single type diatom metrics. Finally, more data accumulation from all over Korea and the development of acceptable diatom metrics were required.

• Tribology and Lubricants
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• v.30 no.5
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• pp.256-264
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• 2014

Enhancing the value of fine chemicals based on biomass resources is an important objective for addressing environmental and other concerns such as demand for renewable or green products, as well as from the political perspective to reduce dependence on fossil feedstock associated with the use of petroleum-based products. Based on these considerations, we studied the synthesis of estolide using waste plant-based oil materials and their application as lubricants and pour point depressants. Five estolides were prepared by varying molar ratio of palmitic acid (PA) to oleic acid (OA) using a reaction time of 48 h. The estolides were characterized by size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR). The isolated yields were in the range of 57-78 % and purity was 93-97%, showing iodine values of 18.2-37.8, total acid numbers (TANs) of 75.6-94.2 mg KOH/g and estolide numbers (ENs) of 1.2-1.8. Increasing the ratio of OA to PA in the synthesis decreased the kinematic viscosity and clouding point of the estolides. Four ball wear test of the estolides as a base oil demonstrated that the wear scar diameter (WSD) of the estolides was significantly lower (0.320-0.495 mm) than the WSD of general base oils such as 150N and Yubase (0.735 and 0.810 mm, respectively), indicating better wear resistance of the estolides. However, the lubricant property was found to be independent of the amount of OA in the estolides. These new materials are prospective candidates for application as a lubricant base oil.