• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.981-989
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• 2020

In this study, a self-made customized phantom was used to quantitatively measure the change in CT number and noise according to the change of pitch. In order to acquire an image using the phantom, the inside of the phantom was filled with sterile distilled water. Inside the glass tube, a solution obtained by diluting the ratio of normal saline and contrast medium to 100%(NS), 400:1, 200:1, 100:1, 50:1, respectively, was placed and imaged. At this time, the pitch was divided into steps of 0, 0.35, 0.7, 1.05, and 1.4 for each dilution ratio of the solution and imaged, respectively. One-way ANOVA analysis were performed to verify whether the mean of the CT number and noise values measured in all ROIs by dilution ratio showed a significant difference according to the change in pitch. As a result of the experiment, there was no statistically significant difference in the change of the CT number according to the change in the pitch for each dilution ratio, but the noise value tended to increase with the increase of the pitch, and showed a statistically significant difference. In the spiral image acquisition of CT, noise can be changed to a significant level depending on the pitch. Therefore, it will be necessary to set the quality evaluation items and criteria for CT images using the spiral image acquisition method.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.27-33
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• 2022

Sleep is an essential factor for living a healthy life, but most modern people complain of poor sleep. For these people, as the need for a means to simply evaluate and manage the quality of sleep increases, devices that can check the sleep state at home without monitoring by an examiner are being developed. The smart sleep mask, which is the subject of this usability test, provides bio-signal monitoring while sleeping so that you can conveniently measure and manage your sleep state for yourself. The purpose of this study is to evaluate the usability and safety of the smart sleep mask, to find and prevent potential factors related to errors in use that may occur, and to develop the comfort and safety of this product. As a result of the formative evaluation of the sleep mask prototype, it was reported that it was difficult to turn on the power and check the results, and that the sleep mask was not comfortable to wear. Different opinions were presented on the size and weight of the sleeping mask by people in different age groups.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.4
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• pp.40-49
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• 2020

Recently, the form of education has changed from one-way to two-way and mutual exchange rather than the existing one-way order form, and accordingly, it is necessary to consider creating a suitable learning environment for each type of education. The basic form of education consists of the delivery of knowledge, that is, the delivery of knowledge by teachers to education consumers through voice delivery, so the sound environment is considered an essential factor in creating a pleasant learning environment. The indoor sound environment is very closely related to the mental stress of the inmate, so the quality level of education will also change greatly depending on whether or not the appropriate sound environment is created. However, the importance of the sound environment in educational facilities such as classrooms has not been highlighted due to the lack of research and related laws on the sound environment. Therefore, in this study, auditory tests were conducted using the auralization based on the physical acoustic performance data presented in the preceding study. Through this, we wanted to verify the validity of this research by analyzing the subjective acoustic performance satisfaction of the occupants due to the improvement of the physical acoustic performance. Based on these research results, it is estimated that the improvement of the sound environment of educational facilities through remodeling in the future will be possible to verify whether the sound environment suitable for educational facilities is created only after the analysis stage on the improvement of subjective sound performance as well as physical sound performance.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.367-378
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• 2021

Field compost is a representative non-point pollution source for livestock. If the field compost flows into the water system due to rainfall, nutrients such as phosphorus and nitrogen contained in the field compost can adversely affect the water quality of the river. In this paper, we propose a method for detecting field compost using unmanned aerial vehicle images and deep learning-based semantic segmentation. Based on 39 ortho images acquired in the study area, about 30,000 data were obtained through data augmentation. Then, the accuracy was evaluated by applying the semantic segmentation algorithm developed based on U-net and the filtering technique of Open CV. As a result of the accuracy evaluation, the pixel accuracy was 99.97%, the precision was 83.80%, the recall rate was 60.95%, and the F1-Score was 70.57%. The low recall compared to precision is due to the underestimation of compost pixels when there is a small proportion of compost pixels at the edges of the image. After, It seems that accuracy can be improved by combining additional data sets with additional bands other than the RGB band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.637-648
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• 2021

In order to support the establishment of a farming plan, it is important to preemptively evaluate crop changes and to provide precise information. Therefore, it is necessary to provide customized information suitable for decision-making by farming stage through scientific and continuous monitoring using drones. This study was carried out to support the establishment of the farming plan for ground vegetable. The cultivation management map of each information was obtained from preliminary study. Three cultivation management maps include 'field emergence map', 'stress map' and 'productivity map' reflected spatial variation in the plantation by providing information in units of plants based on 3-dimensions. Application fields of the cultivation management map can be summarized as follows: detect miss-planted, replanting decision, fertilization, weeding, pest control, irrigation schedule, market quality evaluation, harvest schedule, etc.

• (The)Korea Educational Review
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• v.24 no.2
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• pp.51-79
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• 2018

The purpose of this study is to critically reflect on whether the higher education(HE) restructuring & funding policy proposed by the Moon administration can properly tackle the structural problems confronting Korean HE system. The three major structural problems having entrenched during the rapid expansion of Korean HE system since 1945 can be identified as (1) a 'high cost - low efficiency system' based heavily on 4-year private universities, (2) lack of clear distinction of the roles and connection among different types of higher education institutions (HEIs), and (3) provider-oriented education system and culture seemingly still being widespread at Korean HEIs. This study analyzed the validity of Moon Administration's HE restructuring and funding policy from both a macro- and micro-perspective. From a macro-perspective, this study raised concerns regarding the projects to nurture a national university and a government-dependent private university which will require huge public money. In terms of both the feasibility to secure enough funds and the validity of the proposed policy measures in the existence of unclear roles between public and private HEIs in Korea, this study criticized these policies and proposed, as an alternative policy measure, a low-cost and flexibly operated HEIs such as a government-dependent polytechnic, and a measure to increase connection between different types of HEIs. From a micro perspective, this study suggested, based on 'the expanded principal-agent theory (Waterman & Meier, 1998)', that it would be considered to introduce a more flexible approach in designing the level of government intervention depending upon the maturity of quality assurance procedure at individual universities and the level of goal conflicts between government and individual university.

• 한국사회정책
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• v.24 no.1
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• pp.239-275
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• 2017

The purpose of this study is to explore what social workers experience and how they experience the needs of Meritocracy in the social welfare organization in the neoliberalism.. Therefore, in-depth interviews were conducted with 18 social workers, and I analyzed Colaizzi(1978) in a phenomenological method through collected research materials. As a result, the analysis is integrated in a total of four essential themes. According to the research results, the meritocracy - oriented phenomenon in the social welfare organization was 'paradox of Meritocracy'. Participants were buried in creating "nominal performance without any effectiveness" based on effectiveness and efficiency. Clients were instrumentalized in performance; moreover, they lost contact points with the field. Above all, there was "a reorganization of practices" that contradicted the original values of practice, in which the quality deterioration of service and the connection between organizations were weakened. In addition, the implementation of accountability of social welfare organization, which was intended by Meritocracy, has become a criterion for external evaluation, and the challenge of uncertain result has left a "rigid accountability without discretion." While participants were devoted to making a nominal performance, they failed to be guaranteed by the distinct characteristics of social welfare group. They experienced lost pride of the practitioner in the reality which contained the value of social welfare. However, in spite of this paradox of Meritocracy, participants demonstrated flexibility in order to preserve the original value and reached "a compromise with reality in the identity conflict." Based on the results of the research, I presented the discussion and policy directions.

• Korean Journal of Community Nutrition
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• v.25 no.6
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• pp.485-501
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• 2020

Objectives: The purpose of this study was to examine the biochemical characteristics and dietary intake of adolescents aged 12 to 18 years according to the frequency of milk consumption. Methods: Data from the 2010~2011 Korea National Health and Nutrition Examination Survey was used for the study. The study examined adolescents' (12~18 years) demographic characteristics (house income level, residence region, skipping or not-skipping of breakfast/lunch/dinner, eating-out frequency), anthropometric characteristics (height, weight, weight status), biochemical characteristics (fasting plasma glucose, blood urea nitrogen, creatine, triglycerides, cholesterol, HDL-cholesterol, hemoglobin, hematocrit) and nutrient intakes through quantitative and qualitative evaluation using the Korean Dietary Reference Intakes (KDRI), index of nutrition quality (INQ), nutrition adequacy ratio (NAR) of 3 groups (< 1/week, 1~6/week, ≥ 1/day) according to the frequency of milk consumption. Results: There were significant differences in gender and income levels among the 3 groups. There were no differences in height, weight, and weight status among groups. There were differences in biochemical characteristics and nutrient intake. In boys, there were differences in the mean of BUN and HDL-cholesterol, in quantitative intakes of riboflavin, calcium, phosphorus, potassium by KDRI levels, in qualitative intakes of riboflavin, calcium, phosphorus by INQ and riboflavin, calcium, phosphorus by NAR among 3 groups. In girls, there were differences in the mean of blood urea nitrogen, creatine, HDL-cholesterol, in quantitative intakes of protein, riboflavin, calcium, phosphorus by KDRI levels, in qualitative intakes of riboflavin, calcium, phosphorus by INQ and riboflavin, calcium, phosphorus by NAR among the 3 groups. Conclusions: In Korean adolescents, boys had a higher frequency of milk consumption than girls, and higher the income level, higher the frequency of milk consumption. Consumption of milk appeared to have a positive association with triglycerides, HDL-cholesterol, and indices related to muscle mass. Regular consumption of milk is an important factor in enhancing the intake of riboflavin, calcium, and phosphorus, which adolescents lack. The results of the study indicate a need to prepare an environment and education program to increase milk consumption in adolescents at home and school.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.35-43
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• 2021

Citrus quality is generally determined by its sugar content and acidity. In particular, sugar content is a very important factor because it determines the taste of citrus. Currently, the most commonly used method of measuring citrus sugar content in farms is a portable juiced sugar meter and a non-destructive sugar meter. This method can be easily measured by individuals, but the accuracy of the sugar content is inferior to that of the citrus NongHyup official machine. In particular, there is an error difference of 0.5 Brix or more, which is still insufficient for use in the field. Therefore, in this paper, we propose an AI model that predicts the citrus sugar content of unmeasured days within the error range of 0.5 Brix or less based on the previously collected citrus sugar content and meteorological data (average temperature, humidity, rainfall, solar radiation, and average wind speed). In addition, it was confirmed that the prediction model proposed through performance evaluation had an mean absolute error of 0.1154 for Seongsan area and 0.1983 for the Hawon area in Jeju Island. Lastly, the proposed model supports an error difference of less than 0.5 Brix and is a technology that supports predictive measurement, so it is expected that its usability will be highly progressive.