• 한국분무공학회지
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• 제16권3호
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• pp.146-151
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• 2011

LPG(Liquified Petroleum Gas) fuel for vehicles has lots of advantages such as low emission level, cheaper fuel cost and enough infrastructure. Therefore it arouses interest as an alternative engine to reduce emission of diesel engines. Especially MPI(Multi Point Injection) type LPLi(Liquid Phase LPG injection) system could have overcome the disadvantages of mixer types such as low engine performance, decreased charging efficiency and cold starting difficulty. However ice formation on the nozzle tip and intake port due to the freezing of moisture around the components is often observed in LPLi systems. This icing phenomenon is the direct cause of unstable engine combustion, resulting in engine emissions. Therefore in this research, a spray visualization test for LPG injection was carried out to obtain the basic information of an LPLi injector, then the effects of butane and propane mixing rates on ice formation at the intake port and nozzle tip was investigated. As a result, the icing characteristics of them showed contrary results according to the mixing rates.

• 한국의류학회지
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• 제42권3호
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• pp.474-485
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• 2018

Smart sensors and connected devices have changed the concept of garments along with IT technology convergent garments that transform the performance of basic functions. Various types of products have been researched and developed due to the increased interest in smart clothing; in addition, studies based on physical and mechanical properties have also been actively studied to improve accuracy and reliability. This study represents a basic study for the development of smart textiles based on motion recognition for the surfing practice of beginners interested in IT convergence type. A physical durability evaluation of conductive yarn according to sewing method was later carried out. This study is a conditional specimen sewn with cotton lower thread and 100mm pattern length based on the results of previous studies. The durability of the conductive yarn according to the sewing method was evaluated according to the sewing method. Durability was evaluated by two kinds of repeated strain and abrasion tests. The specimen with applied cotton in a lower thread zigzag pattern 2mm stitch size 100mm stitch length was shown to have the most suitable durability for smart textile.

• Journal of Information Processing Systems
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• 제13권4호
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• pp.876-892
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• 2017

A virtual reality is a virtual space constructed by a computer that provides users the opportunity to indirectly experience a situation they have not experienced in real life through the realization of information for virtual environments. Various studies have been conducted to realize virtual reality, in which the user interface is a major factor in maximizing the sense of immersion and usability. However, most existing methods have disadvantages, such as costliness or being limited to the physical activity of the user due to the use of special devices attached to the user's body. This paper proposes a new type of interface that enables the user to apply their intentions and actions to the virtual space directly without special devices, and test content is introduced using the new system. Users can interact with the virtual space by throwing an object in the space; to do this, moving object detectors are produced using infrared sensors. In addition, the users can control the virtual space with their own postures. The method can heighten interest and concentration, increasing the sense of reality and immersion and maximizing user's physical experiences.

• 방사선산업학회지
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• 제10권4호
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• pp.219-225
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• 2016

The apron is one of the essential protectors to reduce the exposure dose of radiological technologists. This study is to provide a guideline for purchasing the aprons with excellent performance and to help reducing the exposure dose by measuring the shielding ration and uniformity of aprons according to lead equivalent and form types. The shielding ratio of aprons were measured by using radiation generator and dosimeter. Exposure conditions were 81 kVp, 25 mAs, source to image receptor distance (SID) 100 cm and field of view (FOV) $17^{{\prime}{\prime}}{\times}17^{{\prime}{\prime}}$. Exposure areas for front type and around type aprons were divided into 9 areas and for 2 pieces type aprons were divided into 3 areas of top and 4 areas of skirt. The uniformity of aprons were measured by using fluoroscopy and Image J. The 4 regions of interest (ROI) were set into acquired images and measured uniformity by measuring the standard deviation of pixel intensity in ROIs. In continuous shielding ration measurement of aprons according to exposure area, there was not statistical significance (P>0.05). In ANOVA test of aprons, there was statistical significance (P<0.01). In the results of sheilding ratio, although the aprons had equal lead equivalent, there were difference in shielding ratio from 83.59% to 98.15%. In the results of uniformity, the front type aprons with equal lead equivalent indicated the similar uniformity. However, the around type and 2 pieces type apron with equal lead equivalent indicated the different uniformity each other, from 1.8 to 22.2. If the performance evaluation in this study were conducted regularly before and after purchase the aprons, the exposure does to patients and radiological technologists could be reduced.

• 한국의류학회지
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• 제34권2호
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• pp.226-241
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• 2010

This study details the history and characteristics of consumption values, text style analyses, and appeal types expressed in magazine commercials from 1955 to 2008. This study analyzes the level of the social structure of commercial expression for each period. Consumption values based on the categories of consumption values by Sheth (1991) were classified through a total commercials analysis. Analyses on closing types of sentences, types of sentences, and rhetorical figures were executed focusing on headline text and text style. Appealing types were composed of rational, emotional, and ethical appeals. For analysis, the crosstab analysis and chi-square test of SPSS are used. The results are as follow. Seven values were constructed, functional value, social value, emotional value, conditional value, epistemic value, fashionable value, and indistinct value. The ratio of emotional value was the highest and functional value, epistemic value conditional value, fashionable value, social value, and indistinct value followed. The emotional value social value, conditional value, fashionable value, and epistemic value that focused on the emotion of consumers increased, while the functional value decreased. Sentences that use narrative styles, hyperboles, and metaphors that increased the interest of readers were dominantly used in the headline texts. For sentence expression, a declarative sentence in a sentence type, exciting curiosity in the expression method where hyperbole and figures of speech in rhetorical expressions are used most often. Emotional appeal was used almost twice more than the reasonable appeal for appeal types of the total commercial. The lower level of reasonable appeal is information that provides the product function. Interest and expression (such as pleasure and achievement) were used most often for emotional appeal. These results show that the most important issue is the emotional value in consumption in understanding the consumer. Marketing managers should also be aware of the functional value as well as an emotional value.

• Imaging Science in Dentistry
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• 제50권3호
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• pp.227-236
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• 2020

Purpose: Image artifacts caused by patient motion cause problems in cone-beam computed tomography (CBCT) because they lead to distortion of the 3-dimensional reconstruction. This prospective study was performed to quantify patient movement during CBCT acquisition and its influence on image quality. Materials and Methods: In total, 412 patients receiving CBCT imaging were equipped with a wireless head sensor system that detected inertial, gyroscopic, and magnetometric movements with 6 dimensions of freedom. The type and amplitude of movements during CBCT acquisition were evaluated and image quality was rated in 7 different anatomical regions of interest. For continuous variables, significance was calculated using the Student t-test. A linear regression model was applied to identify associations of the type and extent of motion with image quality scores. Kappa statistics were used to assess intra- and inter-rater agreement. Chi-square testing was used to analyze the impact of age and sex on head movement. Results: All CBCT images were acquired in a 10-month period. In 24% of the investigations, movement was recorded (acceleration: >0.10 [m/s²]; angular velocity: >0.018 [°/s]). In all examined regions of interest, head motion during CBCT acquisition resulted in significant impairment of image quality (P<0.001). Movement in the horizontal and vertical axes was most relevant for image quality (R²>0.7). Conclusion: Relevant head motions during CBCT imaging were frequently detected, leading to image quality loss and potentially impairing diagnosis and therapy planning. The presented data illustrate the need for digital correction algorithms and hardware to minimize motion artefacts in CBCT imaging.

• 한국안전학회지
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• 제31권5호
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• pp.133-140
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• 2016

Most small weir installed in Korea is concrete solidated weir. Fixed weir causes stagnant flow, which leads to deposit sediment just upstream of weir. As time goes on, it would induce reduction of water storage capacity and invoke the serious water quality issues. Therefore, there has been a growing interest in movable weir. Especially, the flexible rubber weir is easy to install and possible to operate in extreme environments. However, even though this type can be flatable, it is also not free from sediment deposition problem. Thus, to enhance the ability of releasing deposition the bypass pipe was constructed underneath it. In this study the performance of its ability was examined with hydraulic model test. This bypass pipe was designed with 3 different dimensions to connect between each bottom of upstream and downstream of a weir, such as Type A, B, and C. The efficiency of drainage of deposition upstream was studied under two water of upstream and sediment heights. In addition, the ability of sediment emission through the bypass pipe after the pipe was blocked by debris like soil, vegetation et al. was examined by video monitoring. From this study, it was suggested a dimensionless equation which show the relationship of variable parameters and amount of emission sediment through bypass pipe. And it was found that the most significant factors on efficiency of releasing were elbow angle and discharge, and the ability of emission when the pipe was blocked was most highly influenced in tilting length.

• 한국콘텐츠학회논문지
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• 제18권7호
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• pp.330-337
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• 2018

최근 사용자 중심의 스마트시티 서비스에 관한 관심이 높아지고 있다. 본 연구는 사용자 중심의 스마트시티 서비스를 계획하 기 위한 사전 연구로 사용자의 니즈를 조사하였다. 본 연구는 스마트시티 서비스에 대한 니즈를 도출하기 위해 GIS 기반 위치분석데이터와 비디오 에스노그래피 방법론을 활용하고자 한다. 본 연구는 스마트시티 테스트베드로 선정된 대전 도안지구의 현장조사를 통해 사용자의 집객도가 높은 지역을 세부조사대상지로 선정하고, 도로교통공단의 교통사고분석시스템(TAAS : Traffic Accidents Analysis System)의 위치분석데이터를 이용하여 주변 보행환경을 함께 조사하였다. 또한 비디오 에스노그래피의 고정카메라기법을 통해 사용자의 행위 유형과 변화를 관찰하였다. 추출된 영상데이터를 통해 사용자의 활동을 11개의 세분화 된 유형으로 분류하고, 관찰되는 문제점 및 특이사항을 분석하였다. 본 연구를 통해 조사된 사용자 행위특성은 향후 사용자 중심 스마트시티 서비스를 제안할 수 있는 근거를 마련한다는 점에 의의가 있다.

• 한국의상디자인학회지
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• 제16권3호
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• pp.101-115
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• 2014

This study evaluated the effect of image type of the beauty trainer on satisfaction and stress regarding the major. The data were analyzed by spss 18.0. Frequency analysis, causal analysis, reliability analysis, T-test, one-way variance analysis, and multiple regression analysis were carried out, and the result is as following. First, as the result of analysis the image of beauty trainer, we defined inner, outer, and social image. Second, the difference between images of beauty trainers revealed that people with high interest in the major ranked the inner image of beauty trainer the highest. Respondent with the lowest and the higher class satisfaction also deemed inner image important. The same was for respondents with beauty awareness. For outer image, people with the lowest class satisfaction ranked outer image the highest. And people with beauty awareness recognized beauty trainer's outer image more important. Respondents who said the major have bleak future deemed outer image even important. While the social image was recognized the highest by respondents with lowest class satisfaction. Third, as we analyzed the correlation between the image type of beauty trainer and major stress/satisfaction, the higher the satisfaction for the trainer's outer and social image gave higher class satisfaction. And less stress about the major resulted in higher major satisfaction. Fourth, we evaluated the effect of trainer's image on the class satisfaction and stress. Fifth, the lower the awareness of inner image and the higher awareness of social image resulted in higher major stress. Lower inner image gave high major satisfaction, while high social image resulted in high major stress.

• 환경영향평가
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• 제21권6호
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• pp.903-916
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• 2012

We need to use aesthetic landscape assessment(ALA) as the means of riparian buffer zone(RBZ) management. This study verified the political validity of designation policy of RBZ and land purchase policy. The purpose of this study was to propose RBZ landscape management strategies through ALA of RBZ in Gyeongan Stream for the better attractive and healthy riparian landscapes. The natural type landscape units(LUs) covered 40.9% of the entire area and the cultivated land type LUs covered 20.58%. Landscape assessment consisted of landscape quality and landscape integration assessment. The criteria for assessing landscape quality(LQ) were naturalness, interest, uniqueness, and landscape function. LQ was ranked into five grades using a matrix. The landscape integration assessment consisted of an inner integration assessment in each LU and outer integration assessment among LUs. To review the propriety of designating the riparian area and the riparian ecological belt, differences in ecological appraisal and aesthetic valuation were reviewed through a t-test, Oneway ANOVA, and logistic analysis. The results of ALA, 29.15% of the entire area scored at grade 1 in LQ, while 31.95% scored at grade 5, indicating that grade 5 areas occupied a high share. Surveyed areas were divided into designated RBZ and undesignated RBZ. Results indicated that designated RBZ scored grade 1 in LQ took up 33.2% of the total, significantly higher than the 23.3% taken up by undesignated RBZ. When examined according to buffer distance, grade 1 areas within 50m took up 50.2% of the total area, lower than the 32.7% at buffer distances of 500m-1km. Results indicated a 1% statistically significant difference. Accordingly, analysis was undertaken for the expansion of designation of the riparian area and the selection of appropriate land for formation of a riparian ecological belt, and was designated at priority 1 and 2 for land purchase. This study can also contribute to the formation of a riverine eco-belt through discovery of design factors for upgrading the ecology, aesthetics, and landscape of the riparian area and application in determining land purchase priorities.