• The Journal of Bigdata
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• v.7 no.2
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• pp.235-244
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• 2022

The rental history data of public bicycles in Seoul were analyzed to examine how pandemic phenomena such as COVID-19 caused changes in people's micro mobility. Data for 2019 and 2021 were compared and analyzed by dividing them before and after COVID-19. Data were collected from public data portal sites, and data marts were created for in-depth analysis. In order to compare the changes in the two periods, the riding direction type dimension and the rental station type dimension were added, and the derived variables (rotation rate per unit, riding speed) were newly created. There is no significant difference in the average rental time before and after COVID-19, but the average rental distance and average usage speed decreased. Even in the mobility of Ttareungi, you can see the slow rhythm of daily life. On weekdays, the usage rate was the highest during commuting hours even before COVID-19, but it increased rapidly after COVID-19. It can be interpreted that people who are concerned about infection prefer Ttareungi to village buses as a means of micro-mobility. The results of data mart-based visualization and analysis proposed in this study will be able to provide insight into public bicycle operation and policy development. In future studies, it is necessary to combine SNS data such as Twitter and Instagram with public bicycle rental history data. It is expected that the value of related research can be improved by examining the behavior of bike users in various places.

• Journal of Korean Society of Forest Science
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• v.97 no.1
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• pp.61-70
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• 2008

This study was conducted to develop a mobile tower-yarder with tractor for agriculture and forestry that is the efficient yarder in steep terrains, thinning operation and small scale logging operation. It was designed and manufactured that the power source of tower-yarder is equiped three hydraulic pump connected to PTO of tractor, and three hydraulic pump is used to operate the four motor for drum, the cylinder for clutch of interlocker, the cylinder for tower expanding and the out-rigger cylinder. It was to adopt the running skyline system and the inter-lock function, and to equip the double capstan drum, the storage drum and the clutch for interlock in the development of tower-yarder. It was to develop the tower-yarder which the winch torque of double-capstan drum, the traction force of double-capstan drum, the number of rotation of double-capstan drum and the line speed is $191kg{\cdot}m$, 1,910 kgf, 220.5 rpm and 138.5 m/min, respectively. And it was known that the optimum flange diameter of the main and haulback storage drum is about 360 mm and about 460 mm in order to storage the main line length of 250m and the haulback line length of 450 m. The carriage was made to adopt the running skyline system and to equip the lock function in order to the convenience of chocking and the fall down preventing of tree. It was provided to develop the wire remote controller for the inter-lock function, the convenience of control and the efficiency of yarding. In development process, this tower-yarder was attached the 3-point linkage hitch equipment and the tire wheel for the traction and moving of tower-yarder. Also, it was equipped that the out-rigger and the guy line in order to raise the safety and efficiency of yarding of tower-yarder.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.365-376
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• 1999

The importance of finishing and polishing the restoration has been described by several authors. The final step provides for improved metallurgical properties, better marginal adaptation, reduced plaque accumulation. Unfortunately, finishing of the restorations can produce damage from temperature rises at the pulpal wall. The aim of this study was to determine the changes in temperature can be occurred during the use of finishing and polishing instruments under a variety of conditions. ; with or without a water coolant, intermittent or continuous operation, high or low rotation speed, remaining dentin thickness and various restorative materials. Class V preparations were cut on extracted molars and restored with composite resin(Z 100), resin-modified glass ionomer cements(Dyract, Fuji II LC), and amalgam. Finishing was done with aluminum oxide coated disc($Sof-lex^{(R)}$ polishing disc, 3M, USA). The following results were obtained. 1. The rise of temperature during polishing of amalgam restorations was the highest among the all experimental groups except polishing with water coolant(P<0.05). However, there were no statistical differences in temperature rises between Z 100, Dyract and Fuji II LC(P>0.05). 2. The intrapulpal temperature was greatly influenced by the applied time, and intermittent polishing was showed significantly lower temperature rises than continuous polishing(P<0.01). 3. The intrapulpal temperature was increased according to the application of polishing regard less of using water coolant. However, polishing with water coolant showed significantly lower temperature in the pulp than not used water coolant(P<0.01).

• The Journal of the Korean bone and joint tumor society
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• v.7 no.4
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• pp.139-143
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• 2001

Purpose : Limb salvage for osteosarcoma of proximal tibia is challenging problem due to difficulties in mobilizing or retracting the main neurovascular structure, inadequate soft tissue coverage, and unsolved problem of patellar tendon reattachment to endoprosthesis. The authors analyzed the functional result of limb salvage using tumor prosthesis with medial gastrocnemius rotation plasty for osteosarcama of the proximal tibia. Materials and Methods : Eleven patients with histologically proven osteosarcoma of the proximal tibia, treated with adjuvant and neoadjuvant chemotherapy and limb salvage operation with tumor prosthesis between January 1992 and December 1998 at our Medical Center, were selected. There were 6 male and 5 female. Age ranged from 15 years to 23.7 years with an average of 23.7 years. Follow-up period ranged from 1 year to 4.5 years with an average of 2.5 years. The final functional result was evaluated using the method by ISOLS, 1993. The factors include pain, functional activities, emotional acceptance, use of external supports, walking ability and gait. Each of the factors has been scored from 0 to 5 depending on the appropriate description or data. The rating score is determined by dividing the individual factor scores into the total score and indicates percentage of normal function. Results : The overall functional result ranged from 53,3% to 86.7% with an average of 68.3% of normal function. In details, the averages were 82.5% for pain, 62.5% for functional activities, 67.5% for emotional acceptance, 77.5% for use of external supports, 62.5% for walking ability, and 57.5% for gait. The average range of motion of the knee joint was $5^{\circ}$ extension and $85^{\circ}$ flexion. Five patients have extension lag ranged from $5^{\circ}$ to $15^{\circ}$ with an average of $10^{\circ}$. Two patients suffered postoperative infection. One was treated with antibiotics injection only, but the other needed removal of the prosthesis and knee fusion. Both of them showed unsatisfactory result. C o n c l u s i o n : The overall functional result after limb salvage using tumor prosthesis with medial gastrocnemius rotational flap for osteosarcoma of the proximal tibia was relatively satisfactory in case of no postoperative infection. The patients were less satisfactory in functional activities, emotional acceptance and gait than pain, use of external supports due to limitation of motion and extension lag. More aggressive postoperative physical therapy and protection with brace for 6~9 months as well as surgical technique is mandatory for more satisfactory result.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.893-910
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• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.150-161
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• 2015

The purpose of this study was to obtain the basic data for the effective development and operation of forest healing by analysing the preference of adults on the forest therapy program. The survey of 516 normal adults on the forest therapy program was conducted. Using SPSS 21.0 Program, data analysis of descriptive statistics and correlation analysis of each program confirmed number of covariate, and so we conducted a factor analysis to short meaningful data. And then we looked at the forest healing program preference difference according to demographic characteristics(sex, age, residence, occupation) through reliability analysis, frequency analysis, T-test, analysis of variance(ANOVA). Facter analysis was performed by use of the VariMax orthogonal rotation factor analysis to abbreviate 37 forest therapy program. Through this, the program has been reduced such as 7 program group(1: psychology-based treatment, 2: teaching and counselling-based treatment, 3: camping and forest bath-based treatment, 4: diet-based treatment, 5: nature and plant-based treatment, 6: meditation-based treatment, 7: respiration and yoga-based treatment) and 7 independent programs(1: sleeping in the forest, 2: vision quest, 3: soaking in water, 4: walking wearing shoes, 5: viewing the forest, 6: mountaineering, 7: athletics in the forest). With this criterion, the forest therapy program difference in accordance with sex, age, residence, occupation has been investigated. First, it was verified that there was a significant difference between male and female in the group of such as psychology-based treatment, diet-based treatment, mountaineering. Second, there appeared a significant difference in groups such as teaching and counselling-based treatment, camping and forest bath-based treatment, nature and plant-based treatment, respiration and yoga-based treatment, athletics in the forest. Third, according to the residence, there appeared a significant difference in groups such as psychology-based treatment, teaching and counselling-based treatment, diet-based treatment, nature and plant-based treatment, meditation-based treatment, vision quest, mountaineering, athletics in the forest. Fourth, according to the occupation, there appeared a significant difference in groups such as nature and plant-based treatment, medication-based treatment, vision quest, walking wearing shoes, viewing the forest, mountaineering. As shown before, it seems to be necessary that we should be mindful of this investigation which shows variety of preference of adults on the forest therapy program according to demographic characteristics. We expect the results of this study to be utilized as basic data for the development of forest therapy program targeting on adults.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.37-46
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• 2009

This research will focus on the public agencies, designers, supervisors, building cooperation, and contractor who involved in urban development plan. By understanding the complexity and the priorities in urban development process, all problems of the urban development projects can be solved or improved. These priorities are specified using AHP (Analytic Hierarchy Process). A questionnaire survey is employed to identify the problems of urban development process and the methods of revitalizing urban in this research. Through the survey, 35 issues are drawn out. Factor analysis technique is applied to extract the underlying interrelationships possibly existing. Using latent root criterion and varimax rotation method, 9 factors are extracted(by using 34 issues after deleting 1 issue less than 0.4 of factor loading) These 9 factors named as PIF (Problem Improvement Factor) consist of integration estimation (PIF1), cooperation operation capability (PIF2), contractor corporation capability (PIF3), capital for infrastructure investment (PIF4), misunderstanding of effective land use (PIF5), financial capability (PIF6), obscure goal of project (PIF7), shortage of cooperation expertise (PIFS), administrative procedures (PIF9). PIF 6 is the most important factor and PIF 1 is the most widely effective factor to succeed urban land development projects. It is recognized that administrative office is most responsible for PIF1 cooperation is most responsible for PIF2, 7, 8 and 9; contractors is most responsible for PIF3 and PIF6; administrative agencies is most responsible for PIF4; cooperation and consultants are responsible for PIF5. From findings in this study, some suggestions are proposed for the revitalization methods of urban development projects through the land readjustment method.

• Journal of Korean Historical Folklife
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• no.44
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• pp.145-176
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• 2014

This study analyzed official duties and personnel practices of Hyangcheong(鄕廳), administrative organization in which sajok(士族) participate this office, and Jakcheong(作廳), hyangree(鄕吏)'s office, of Anbyeon of Hamgyeong Province in the 19th century. Although there have beeen somewhat of case study of Gyeongsang, Honam, etc., study on Hamgyeong Province has been almost nonexistent because of the limitation of materials. Hence, this paper specifically examined Hyangcheong and Jakcheong's official duties and personnel practices through an article of 'a list of Hyangcheong and Jakcheong's officials' of Anbyeon, newly found, which is in the possession of this writer. Especially, this study virtually traced individual ststus and family by analyzing Hyangcheong and Jakcheong's 40-official duties and a list of 330-ofiicial duties for sixs years. And then by comparing it against Jokbo(族譜), I have grasped 19-Famlily of them. Executives of Hyangcheong could be grasped as they were status of Yangban(兩班), but members of Jakcheong were hardly identified because they were status of hyangree, thus most of them were not enscrolled in Jokbo. Hyangcheong and Jakcheong's official duties could be found by compare it with other area in Ehubgi(邑誌) Hamgyeong Province. the features of officiak duties are as in the following. On general administrative organization, Sajok's Hayngcheong, Jakcheong as general administrative organization and Jangcheong(將廳) as police work existed. As Pyeongando and Hamgyeongdo were border areas, Jangcheong was independent and led other institutions. However, in Anbyeon, Hojang(戶長) of Hayngcheong and Jakcheong divided dudies and commanded. Hojang'role was higher than any other areas, Because Hojang is in charge of Jangcheong's functions. Jakcheong was centrally operated by Hojang, Eebang(吏房), and Hyeongbang(刑房), so-called 'Samgonghyeong(三公兄)', Whereas Anbyeon was operated by Hojang, Eebang, Chunchong(千摠). In the general areas, While Juasu(座首) Byeolgam(別監), Executive of Hyangcheong, manages each warehouse(倉) where the nation's tax revenues are kept, In Anbyeon besides Joasu, Hyangso(鄕所). The principle of Hyangcheong and Jakcheong's personnel practices was one-period, but there were many consecutive terms, every other year terms, or tranference into other area. Police work was assumed by specific persons because it was relatively specialized job, However in case of Ghamsaek(監色) of each warehouse(倉), Hyangso(鄕所) of Hyangcheong or Hojang of Jakcheong had held plural offices, and was solely responsible it. On the overall features of its operation, Hyangcheong held plural offices, but rotation was made only within Hyangcheong. On the other hand, in the case of Jakcheong, Hojang, Eebang, and even Buriebang circulated their positions, but the other Hyangree rotated each Saek(色) and Guamguan of each warehouse(倉). This writer confirmed that unlike Gyeongsang and Hamgyeong, Hyangcheoung or duties of Hyangree were not handed from generation to generation by several families and, many families shared their work by circulating positions.