• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.563-576
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• 2012

목적 : 본 연구는 업무형태에 따른 측두하악장애의 유병률과 업무 시 노출되는 직무스트레스 및 구강 내 악습관이 측두하악장애와 어떠한 연관성이 있는지 알아보아 보건학적 기초자료를 제공하고자 실시되었다. 방법 : 본 연구의 자료 수집을 위하여 서울과 경기 일부지역에 근무하고 있는 일반사무직, 서비스직, 교직원으로부터 편의 추출된 452명을 대상으로 2010년 1월부터 2010년 4월까지 설문조사를 실시하였고, 수거된 353명을 연구대상으로 하였다. 설문지는 측두하악장애의 증상, 하악사용에 관한 구강 내 악습관, 직무스트레스, 인구사회학적 특성으로 구성되었다. 측두하악장애의 증상의 정도를 구분하기 위해 설문지의 양성응답 수의 빈도에 따라 무증상인 1단계에서 양성응답 수가 가장 많은 4단계 까지 총 4그룹으로 나누었다. 측두하악장애의 유병률을 알아보기 위하여 빈도분석을 시행하였고, 측두하악장애의 증상의 정도에 따른 여러 요인들 간의 연관성 및 관련요인을 알아보기 위하여 교차분석 및 경향성 분석과 다항로지스틱회기 분석을 시행하였다. 결과 : 측두하악장애의 유병률은 75.4%였고, 측두하악장애에 대한 주관적 증상으로는 관절잡음이 56.4%로 가장 주된 증상 중 하나였으나 남녀 간의 차이는 통계적으로 유의하지 않았다. 다음으로는 두통이나 목의 통증이 36.5%이었고, 귀, 관자놀이, 볼 주위의 통증이 22.1%로 높았다. 측두하악장애의 주관적인 증상 수에 따른 인구사회학적 특성은 증상이 없는 경우 여성에서 19.1%, 남성에서 36.6%로 여성에서 더 높은 유병률을 보였다. 연령별로는 40세 이상의 그룹보다 20 - 30대그룹에서 측두하악장애 증상수가 높아지는 경향을 보였다. 하악 사용과 관련된 악습관 및 직무스트레스는 측두하악장애 증상수와 유의한 관련성이 있는 것으로 나타났는데, 하악 사용과 관련된 습관의 개수가 많아질수록 측두하악장애의 증상의 개수도 많아졌고, 습관이 한 가지씩 늘어날수록 측두하악장애 증상이 없는 1단계보다 3단계가 될 위험이 1.45배, 4단계가 될 위험이 1.57배 높아졌다. 스트레스 수준도 가장 하위단계에서 한 단계 높아지면 측두하악장애 1단계에서 4단계가 될 위험이 2.49배, 두 단계 높아지면 3.43배 높아졌다. 결론 : 본 연구의 결과 측두하악장애와 업무특성에 따른 연관성은 설명하지 못하였지만, 직무스트레스가 높은 경우 측두하악장애 증상의 개수 또한 높아짐을 확인할 수 있었다. 이는 측두하악장애의 주관적인 증상을 발생시키는데 있어서 업무형태 보다는 심인적인 부분이 더 중요한 인자임을 의미한다. 그러므로 측두하악장애 평가 시 신체적인 문제뿐 아니라 행동적, 심리 사회적 문제로 예측인자를 폭넓게 인식함으로써 다각적인 접근을 하는 것이 필요하며, 측두하악장애 증상이 발생된 경우 임상적 치료뿐 아니라 행동요법 및 심리 치료와 자가 관리 등이 함께 수반되어 기여요인 조절을 조절하는 것이 중요하다 하겠다.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.137-144
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• 2012

This study was conducted to determine the effect of feed additives including probiotics, moisture and feed ingredients and the effect of fermented feed on digestibility and volatile fatty acid (VFA) level in finishing pigs. Feed was mixed with microbials including Saccharomyces, Lactobacillus, Enterococcus and Pediococcus together with different levels of probiotics, 0.25, 0.5, 1, 2, 3%. Addition of probiotics showed improved fermentation rate after 48 h incubation. To determine the optimal moisture level for fermentation, different levels of water, 30, 40, 50 and 60%, were added into the feed. Fermentation rate of feed with 40~50% moisture level was higher than that from 60% level at 60 h post-fermentation. In vitro fermentation rate of feed ingredients was analyzed by comparing VFA levels. Beet pulp and tapioca showed higher fermentation rate compare to other ingredients including canola meal or rapeseed meal. To determine the effect of administration of fermented feed In vivo, feces from finishing pigs were analyzed. Finishing pigs administrated with fermented feed showed improved digestibility and higher volatile fatty acid (VFA) level. In conclusion, results from the current study indicate that 40~50% of moisture with addition of beet pulp and tapioca in feed is optimal condition for fermentation. Furthermore, our data suggest that fermentation of feed can improve the feed quality and digestibility, thereby provide more nutrient in finishing pigs.

• Explosives and Blasting
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• v.26 no.2
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• pp.64-76
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• 2008

Bulk Emulsion blasts using mechanized charging system, which is generally used in foreign countries, have recently introduced and gradually increased in Korea. The Bulk Emulsion are safe and able to increase the charging density for improvement of fragmentation and advancement especially in tunneling, and minimizing environmental problem. Because of less toxic gas generation, the explosives are called, namely ech-friendly products. There are two kinds of Bulk Emulsion; one is for open cut and the other is for tunneling. According to features of blast sites and its purpose, the compositions are different, but the principle is the same. In this study, trial blasts using Bulk Emulsion for tunneling had executed at 10 sites in Korea. The major result of the major job-sites is the following. First of all, compared with cartridge explosive, Bulk Emulsion was able to increase its charging density up to $35{\sim}60%$, to decrease the blast holes to approximately $10{\sim}30%$ down, and the advancement was improved up to $8{\sim}20%$ and also 30% up in its fragmentation. Toxic gas production after cartridge blasting showed 34.44ppm of its CO. Bulk Emulsion, however, showed 20.13ppm, which was 58.45% production of the cartridge explosive, and NOx was below 2ppm. The mechanized charging system of Bulk Emulsion should be applied to large sized tunnel blasting, long advanced tunnel which can secure the advancement of over $4{\sim}5m$, and the sites required finishing rapidly.

• Journal of Environmental Impact Assessment
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• v.24 no.6
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• pp.593-606
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• 2015

This study was intended to develop Korean Environmental Sustainable City Index (ESCI) so that local governments can examine and identify urban environment issues and then come up with a policy to improve the environment and urban biodiversity for cities. Green City Index (GCI), Environmental Performance Index (EPI), and City Biodiversity Index (CBI) which have used worldwide were analyzed. Based on the result of analysis, evaluation indicators of ESCI were finally a total of 20 indicators under four categories, which are native biodiversity, living environment, ecosystem services, and governance and management. Then, five cities with biotope mapping and evaluation index were selected to apply ESCI for evaluation. In order to apply ESCI, local governments need to accumulate basic data. There should be a policy which requires local governments to build data for biotope mapping so that the rate of natural area, ecological network and permeable land surface can be evaluated. Indicators must be applied to be compliant with scale of the city and level of data building gradually.

• Science of Emotion and Sensibility
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• v.6 no.3
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• pp.63-72
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• 2003

This study investigated how cognitive style and training context influenced visual discrimination skill acquisition and transfer under time pressure. This experiment consisted of a screening session, a training session, and a transfer session using random polygon comparison tasks. Screening session was designed to separate participants according to their cognitive style (analytic or holistic). Training session was divided into difficult and easy conditions. In transfer session, participants compared polygon pairs in a novel task. The stimuli were presented for 1.5 seconds to examine the influence of time pressure. Through the all sessions, this experiment measured accuracy and response time. According to the results of this study, analytic group responded as quickly as holistic group in the beginning of training session because time pressure induced them to the holistic strategy. However, as training session progressed, their slopes of reaction time increased, suggesting that their own analytic style emerged. Holistic group showed flatter slopes than did analytic group for training session. Of interest is the slopes increased at the beginning of transfer session, suggesting that they developed analytic strategies in difficult training context. It is suggested individuals differently develop strategic processing skills depending on cognitive styles even under time pressure.

• Science of Emotion and Sensibility
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• v.19 no.1
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• pp.3-10
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• 2016

This research was to investigate the effect of fatigue reduction and heart rate recovery (HRR) according to whole body vibration (WBV). 20 healthy participants were recruited and divided into vibration group (VG) and none vibration group (NVG). VG was group with provided vibration and NVG was group without vibration. They exercised slope gait with 8.5 degree and 4km/h during 30min. They rested on the chair type vibrator during 30min. The vibration consists of 10hz as frequency and 5mm as amplitude. We measured the lactate in the blood and HRR before, immediately after exercise and after rest session. The results showed that lactate level in VG the more decreased at 95.2%. The result of HRR was similar including recovery at 50.67% in VG. The WBV with stimulated vessel in muscle assisted the recovery function by reducing the excess post-exercise oxygen consumption (EPOC) quickly and improving blood circulation. The rest with WBV could provide efficient cool-down exercise for elderly and women without other physical activities after exercise.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.197-206
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• 2010

For an emotion retrieval system implementation to support pedestrian navigation, coordinating the pedestrian emotion model with the system user's emotion is considered a key component. This study proposes a new method for capturing the user's model that corresponds to the pedestrian emotion model and examines the validity of the method. In the first phase, a database comprising a set of interior images that represent hypothetical destinations was developed. In the second phase, 10 subjects were recruited and asked to evaluate on navigation and satisfaction toward each interior image in five rounds of navigation experiments. In the last phase, the subjects' feedback data was used for of the pedestrian emotion model, which is called ‘learning' in this study. After evaluations by the subjects, the learning effect was analyzed by the following aspects: recall ratio, precision ratio, retrieval ranking, and satisfaction. Findings of the analysis verify that all four aspects significantly were improved after the learning. This study demonstrates the effectiveness of the learning algorithm for the proposed pedestrian emotion model. Furthermore, this study demonstrates the potential of such pedestrian emotion model to be well applicable in the development of various mobile contents service systems dealing with visual images such as commercial interiors in the future.

• Science of Emotion and Sensibility
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• v.23 no.1
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• pp.17-28
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• 2020

Lowering observers' view-height may increase the amount of occlusion across objects in a visual scene and prevent the accurate identification of the objects in the scene. Based on this possibility, memory stimuli in relation to their expected views from different heights were displayed in this study. Thereafter, visual short-term memory (VSTM) performance for the stimuli was measured. In Experiment 1, the memory stimuli were presented on a grid-background drawn according to linear perspectives, which varied across observers' three different view-heights (high, middle, and low). This allowed the participants to remember both the color and position of each memory stimulus. The results revealed that testing participants' VSTM performance for the stimuli under a different memory load of two set-sizes (3 vs. 6) demonstrated an evident drop of performance in the lowest view-height condition. In Experiment 2, the performance for six stimuli with or without the grid-background was tested. A similar pattern of performance drop in the lowest condition as in Experiment 1 was found. These results indicated that different view-heights of an observer can change the amount of occlusion across objects in the visual field, and the sensory interference driven by the occlusion may further influence VSTM performance for those objects.

• School Mathematics
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• v.12 no.3
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• pp.273-299
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• 2010

The purpose of the study is designing and implementing 'Sampling Distributions Simulation' to help students to understand concepts of sampling distributions. This computer simulation is developed to help students understand sampling distributions more easily. 'Sampling Distributions Simulation' consists of 4 sessions. 'The first session - Confidence level and confidence intervals - includes checking if the intended confidence level is actually achieved by the real relative frequency for the obtained sample confidence intervals containing population mean. This will give the students clearer idea about confidence level and confidence intervals in addition to the role of sampling distribution of the sample means among those. 'The second session - Sampling Distributions - helps understand sampling distribution of the sample means, through the simulation method to make comparison between the histogram of sampling distributions and that of the population. The third session - The Central Limit Theorem - includes calculating the means of the samples taken from a population which follows a uniform distribution or follows a Bernoulli distribution and then making the histograms of those means. This will provides comprehension of the central limit theorem, which mentions about the sampling distribution of the sample means when the sample size is very large. The forth session - the normal approximation to the binomial distribution - helps understand the normal approximation to the binomial distribution as an alternative version of central limit theorem. With the practical usage of the shareware 'Sampling Distributions Simulation', we expect students to have a new vision on the sampling distribution and to get more emphasis on it. With the sound understandings on the sampling distributions, more accurate and profound statistical inferences are expected. And the role of the sampling distribution in the inferences should be more deeply appreciated.

• Tunnel and Underground Space
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• v.25 no.1
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• pp.107-114
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• 2015

This study focuses on assessing risks which might occur in operation stage of CAES storage cavern and analyzing fire scenarios for the risk that have been assessed with highest risk level. Risks in operation stage were categorized into upper risk group and lower risk group. Components of upper risk group are technical risk, facility risk and natural disaster risk. Lower risk group is composed of 11 sub-risks. 20 experts were chosen to survey questionnaires. ANP model was applied to analyze the relative importance of 11 sub-risks. Results of risk analysis were compared with risk criterion to set risk priorities, and the highest risk was determined to be 'occurrence of the fire within the management opening'. Three fire scenarios were developed for the highest risk level and FDS (Fire dynamics Simulator) was used to analyze these scenarios. No. 3 scenario which air blows from tunnel into outside atmosphere represented that a rate of smoke spread was the fastest among three fire scenarios and a smoke descended most quickly below the limit line of breathing. Thus, No. 3 scenario turned out to be the most unfavorable condition when operating staffs were evacuated from access tunnel.