• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.177-186
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• 2017

This study is intended to provide navigator with specific information necessary to assist in the avoidance of collision and in operation of ships to evaluate the maneuverability of research vessel Jera. Authors carried out full-scale sea trials for turning test, zig-zag test, and spiral test at actual sea-going condition, which were performed on starboard and port sides with 10-20 rudder angle at service speed of 10 knots. The turning circle was much different at both of the turning of port and starboard which was longer at the starboard than at the port. In the zig-zag test results, the port and starboard was $10^{\circ}$ the first and second overshoot angles were $6.0^{\circ}$, $5.8^{\circ}$ and $6.3^{\circ}$, $7.1^{\circ}$ respectively and the first overshoot angles were $16.4^{\circ}$, $17.6^{\circ}$ when using $20^{\circ}$. Her maneuverability index T and N can be easily determined by using an analogue computer with the data obtained from the zig-zag tests where K is a constant representing the turning ability and T is a constant representing her quick response. In the zig-zag tests under $10^{\circ}$ or $20^{\circ}$ at rudder angle, the value K is 0.149. 0.123 sec- and T is 11.853 and 6.193 sec and angular velocity is $0.937^{\circ}/sec$ and $1.636^{\circ}/sec$. In the spiral test, the loop width was unstable at $+0.51^{\circ}$ and $-1.19^{\circ}$ around the midship of rudder, but the tangent line at $0^{\circ}$ was close to vertical. From the sea trial results, we found that she did comply with the present criterion in the standards of maneuverability of IMO.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.284-295
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• 2019

This study examined the actual condition of middle school students' dining out based on the data of the 2016 youth food behavior inquiry data of the Korea Rural Economic Institute. The eating out behavior of 278 middle school students' according to gender, average eating-out cost per person, average monthly eating out cost per person, weekly frequency of breakfast, and dietary information source were calculated into a chi-square value by cross analysis. The main results of this study are as follows. First, in middle school students' eating-out status, most students answered 'eating out', and the highest frequency of eating out was 1~3 times a week. The reason for eating out was 'to enjoy delicious food', and 'costly price' was the most common reason for not eating out. Food taste was the most common standard for selecting eating out, and a restaurant was the most common place to eat out. The main restaurant was the 'snack bar (kimbap specialized store)'. Second, there was no significant difference in all items of eating-out status according to the gender. A significant difference in eating out frequency was observed according to average eating-out cost per once (p< .001), standard for selecting eating out (p< .001), main eating out places (p< .001), and main restaurants (p< .01). There was a significant difference in the frequency of eating out (p< .001) in the eating-out status according to average eating out cost per month. Third, the eating-out status according to the breakfast frequency of middle school students had a significant difference in the reason for eating out (p< .001). The eating-out status according to the dietary information source of middle school students had a significant difference in eating out or not (p< .05) and the frequency of eating out (p< .05). These results highlight the importance of school diet education so that middle school students can achieve healthy eating habits and plan to increase their interest and utilization of school dietary education.

• The Journal of Sustainable Design and Educational Environment Research
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• v.18 no.1
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• pp.1-16
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• 2019

The purpose of this study is to diagnose the problems of an elementary school care classroom in terms of facilities and physical environment and to suggest an improvement plan for building safer and more pleasant facilities and environment in further proceeding the policies of a whole-day care classroom. To this end, we analyzed the main contents of the domestic policies for elementary school care classes and the related spatial standards amongst the management plans of provincial education offices nationwide. In addition, we analyzed the relevant care facility standards of advanced countries such as the U.S., Australia, and Singapore and diagnosed the physical environmental level of Korean care classes in comparison to the international standards. Afterwards, we conducted a case study of elementary school care classes in order to examine the key issues with the environment of care classes, the causes of these issues and the user recognition and demand. The key results of this research are as follows. First, it is necessary to elaborate and refine the guidelines on elementary school care classrooms. Second, in order to provide high-quality elementary care services, it is important to have a combined classroom that can be operated at the level equivalent to or similar to a dedicated care classroom. Third, it is necessary to regularly check the facilities and environment of the elementary school care classroom.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.54-70
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• 2023

Surveys and studies on cultural assets using LiDAR measurement are already active overseas. Recently, awareness of the advantages and availability of LiDAR measurement has increased in Korea, and cases of using it for surveys of cultural assets are gradually increasing. However, it is usually restricted to surveys of mountain fortresses and is not actively used for surveys of ancient tombs yet. Therefore, this study intends to emphasize the need to secure fundamental data from LiDAR measurement for the era from the Three Kingdoms to Unified Silla in which recovery, maintenance, etc., in addition to the actual surveys, are unfulfilled due to the sites being mainly distributed in mountainous areas. For this, LiDAR measurement was executed for the area of Jangsan Ancient Tombs and Chunghyo-dong Ancient Tombs in Seoak-dong, Gyeongju, to review the distribution and geographical conditions of ancient tombs. As a result, in the Jangsan Ancient Tombs, in which a precision archaeological (measurement) survey was already executed, detailed geographic information and distribution conditions could be additionally identified, which could not be known only with the layout indicated by the topographic map of the existing report. Also, in the Chunghyo-dong Ancient Tombs, in which an additional survey was not conducted after 10 tombs were found during the Japanese colonial period, the location of the ancient tombs initially excavated was accurately identified, and the status and additional information was acquired, such as on the conditions of ancient tombs not surveyed. Such information may also be used as fundamental data for the preservation and maintenance of future ancient tombs in addition to the survey and study of the ancient tombs themselves. LiDAR measurement is most effective for identifying the condition of ancient tombs in mountainous areas where observation is difficult or access is limited due to the forest zone. It may be executed before on-site surveys, such as archaeological surveys, to secure data with high availability as prior surveys or pre-surveys. Therefore, it is necessary to secure fundamental data from LiDAR measurement in future surveys of ancient tombs and to establish a survey and maintenance/utilization plan based on this. To establish survey/study and preservation/maintenance measures for ancient tombs located in mountainous areas, a precision archaeological survey is currently executed to draw up a distribution chart of ancient tombs. If LiDAR measurement data is secured before this and used, a more effective and accurate distribution chart can be drawn up, and the actual conditions can be identified. Also, most omissions or errors in information can be prevented in on-site surveys of large regions. Therefore, it is necessary to accumulate fundamental data by actively using LiDAR measurement in future surveys of ancient tombs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.34-41
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• 2021

Sidewalks are facilities used for the safe and comfortable passage of pedestrians and are paved with blocks of various materials. Currently, Korea does not have a quantitative survey method for the pavement condition of sidewalks, so it is necessary to develop an efficient survey method. Drones are being used as an efficient survey tool in various fields, but there are limited studies in which sidewalks have been investigated. This study investigates the possibility of detection by limiting the missing sidewalk blocks using a drone. This study is an initial study on the development of a method for detecting damage in sidewalk blocks. For this, sidewalk blocks were artificially removed to simulate a dropout situation, and images were acquired with 0.7-cm resolution using a drone. As a characteristic of the point cloud data acquired through image pre-processing, there was high variance of the elevation of the points in the missing area of the sidewalk block. Using these characteristics, an experiment was conducted to detect the missing parts of the sidewalk block by applying four thresholds to the variance of the elevation of points included in the grid corresponding to the sidewalk area. As a result, the detection accuracy was shown with a positive detection ratio of 70-80%, omission errors of 20-30%, and commission errors lower than 2%. It is judged that the possibility of detecting missing sidewalk blocks is high. This study focused on detecting a simulated missing sidewalk block in a limited environment. Therefore, it is expected that an efficient and quantitative method of detecting damaged sidewalk blocks can be developed in the future through additional research with considerations of the actual environment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.13-24
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• 2020

A systematic approach to assess the safety of corrugated steel plate structures has not been established yet. Therefore, an improved safety assessment procedure was proposed in this study by considering the characteristics of corrugated steel plate structures in which the dead load of backfill soil is dominant and the live load effect is minimized. The proposed procedure can consider the combined effect of axial force and bending moment on the safety, based on the Soil-Culvert Interaction (SCI) method, and can differentiate the maintenance scheme according to the calculated plasticity index. There is also an advantage in enhancing the accuracy of assessment, utilizing the measured displacements. Furthermore, improved methods were proposed by discussing various ways for reasonably improving the proposed assessment procedure. The safety of an actual structure and a full-scale test specimen was assessed by applying the proposed procedure. The conventional assessment procedure significantly overestimated the load-carrying capacity, whereas the proposed procedure resulted in a reasonable level of safety. Therefore, the procedure proposed in this study is expected to contribute to the establishment of proper maintenance plan such as the quantitative condition assessment and strengthening of corrugated steel plate structure.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.14-21
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• 2019

The construction phase of the construction project needs a large scale of manpower, materials and equipment. Among them, manpower is a core part for project construction. These manpower are divided into two groups. The first is the management group that manages the construction, and the second is the site technician manpower for construction work. Recently, construction company has suffering due to the insufficient supply of technician labor. Accordingly, this study will perform an empirical analysis about the construction technician. To do this, we surveyed related research trends and conducted surveys on the satisfaction of the construction technician. The result, satisfaction with pay and insurance was relatively low compared to other items. Therefore, this study were conducted in-depth interviews with technician managers in order to analyze the cause. In addition, case analysis was conducted to analyze actual working conditions. As a result, it was analyzed that the wage level and insurance system of construction technician were considerably stable compared to the manufacturing industry. The result of this study is expected to contribute to the activation of excellent technician cultivation through the change of recognition about construction technician.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.13-23
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• 2021

In this study, we performed a Random Walker analysis to predict the Major Movement Paths of otters. The scope of the research was a simulation analysis with a radius of 7.5 km set as the final range centered on the Ansim-wetland in Daegu City, and a field survey was used to verify the model. The number of virtual otters was set to 1,000, the number of moving steps was set to 1,000 steps per grid, and simulations were performed on a total of 841 grids. As a result of the analysis, an average of 147.6 objects arrived at the boundary point under the condition of an interval of 50 m. As a result of the simulation verification, 8 points (13.1%) were found in the area where the movement probability was very high, and 9 points (14.8%) were found in the area where the movement probability was high. On the other hand, in areas with low movement paths probabilities, there were 8 points (13.1%) in low areas and 4 points (6.6%) in very low areas. Simulation verification results In areas with high otter values, the actual otter format probability was particularly high. In addition, as a result of investigating the correlation with the otter appearance point according to the unit area of the evaluation star of the movement probability, it seems that 6.8 traces were found per unit area in the area where the movement probability is the highest. In areas where the probability of movement is low, analysis was performed at 0.1 points. On the side where otters use the major movement paths of the river area, the normal level was exceeded, and as a result, in the area, 23 (63.9%), many form traces were found, along the major movement paths of the simulation. It turned out that the actual otter inhabits. The EN-Simulator analysis can predict how spatial properties affect the likelihood of major movement paths selection, and the analytical values are used to utilize additional habitats within the major movement paths. It is judged that it can be used as basic data such as to grasp the danger area of road kill in advance and prevent it.

• Korean Journal of Family Social Work
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• no.53
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• pp.45-78
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• 2016

The purpose of this study is to classify the old into the old people as Young-old(Age 65-74) and Old-old(Older than 75) Elderly in Korea and is to check the factors influencing on the suicidal ideation based on eco-system approach. For the research data, the survey data of actual condition of the old people in 2014 was used. The samples of analysis in this study are the Young-old people who have spouse Old-old people, which are in total 6, 201. In order to check the characteristics of suicidal ideation of the Young-old people and Old-old people, Chi-square analysis was implemented and binomial logistic regression analysis was conducted to check the influencing factors of suicidal Ideation of Young-old and Old-old Elderly. As a result of analysis, there were significant difference in the factors influencing on suicidal ideation of the Young-old people and the Old-old people. The variables in terms of the sociology of population among personal system factors have affected more to the suicidal ideation of Old-old people than the Young-old people. Variables in terms of health have influenced on the Old-old people and the variables in terms of economy have significantly affected to the Young-old people. It has been suggested that the conflict of conjugality and marital conflict affect to the suicidal ideation of Young- old people however it has been appeared that the Old-old people are significantly affected not only by the conjugality but also by the relationship with children. In order to reduce the suicidal ideation of the old people, the customized approach per group of the old people has been presented.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.323-334
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• 2011

The purpose of this study is to grasp the actual condition for social exclusion for the elderly, to understand the predictive factors of social exclusion. To achieve this objective, the social exclusion for the elderly was examined targeting 4,040 old people in more than 65 years old by using the second data for Korean Longitudinal Study of Ageing(KLoSA) in 2008 by Korea Labor Institute. First, as a result of examining the actual condition for social exclusion for the elderly, the old people were indicated to be 45.4% for economic exclusion, 78.7% for working exclusion, 17.8% for residing exclusion, 43.8% for health exclusion, 33.7% for educational exclusion, and 34.3% for social-activity exclusion. Second, the possibility to be excluded economically was indicated to be bigger in the older age, in a case of not residing in a city and in the more number in household members. The possibility to be excluded from working was indicated to be higher in a case that old person is woman, in the older age, in a case that old person’s religion is christianity, in a case without spouse, in the more residing in a city, in a case that a household type is poor, in a case of dwelling in apartment, in the more number in household members. The possibility to be excluded from residing was indicated to be higher, in a case without spouse, in the more residing in a city, in a case that a household type is poor, in a case that a residing house type is general house, and in the less number in children. The possibility to be excluded from education was indicated to be higher in a case that old person is woman, in the older age, in a case that religion is not Christianity, in a case without spouse, in a case of not residing in a city, in a case that a household type is poor, in a case of the more children alive. The possibility to be excluded from health was indicated to be higher in a case that old person is woman, in the older age and in a case that a household type is poor. The possibility to be excluded from social activity was indicated to be higher in a case that old person is woman, in the older age, in a case that religion is not Christianity, in a case that a household type is poor, in a case of dwelling in apartment. This study has value as a basic research on social exclusion for the elderly.