• Proceedings of the KSR Conference
• /
• 2002.05a
• /
• pp.498-502
• /
• 2002

Section insulators are indispensible devices for the electric railways, which divide electrical connections between the trolley lines without losing mechanical connections, and this means that they should have both good electrical insulation performance and mechanical performance for pantograph interaction. This paper reviews some technical aspects of the several type section insulators and makes analysis of difficulties during operation. The closed type section insulators are proposed for newly electrified railways, because they have good mechanical and electrical performances for high speed trains up to 200[km/H]. Technical specifications of closed-type section insulators based on survey of the advanced technologies are provided, and also the neutral section configuration method which might be the best solution for newly electrified railways in Korea of 200km/H speed.

• Journal of the Economic Geographical Society of Korea
• /
• v.23 no.4
• /
• pp.408-424
• /
• 2020

This study attempts to analyze the spatial clustering of survived and closed coffee shops based on the land price and land use for each coffee shop location. The locational characteristics of survived and closed coffee shops for each cluster type are identified through various locational properties such as transport factors (physical accessibility), shop properties (franchise information, newly open/closed business experience), and spatial density (kernel density estimation). To this end, we categorize the clusters of survived and closed coffee shops into three types (general locational distribution type, commercialization type of residential area and location type of commercial center), and then analyze their locational characteristics. As the result, we found that the locations of newly open and closed coffee shops show different distribution characteristics, even though they are classified into the same type due to the double sidedness of new open and closed locations. The results of this study can be provided as basic data for planning the location of coffee shop as well as regional commercial district.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.2
• /
• pp.104.1-104.1
• /
• 1997

The purpose of this study is to grasp the characteristics of user''''s response to perceived safety and visual preferences for outdoor green spaces by the types of campus layouts. This research was investigated by color slide ratings and questionnaire survey to the students who are majoring in Landscape architecture in three universities locating at Taegu area. Two research sites have similarities in many ways but have differences in campus land form and design type such as ''''Closed'''' and ''''Open'''' types. Major results were summarised as follows ; 1. As a result of the slide test, the high degree of visual preference was shown in the campus that is ''''Closed'''' type. However the degree of perceived safety was lower than that of in Youngnam Univ. campus. 2. According to the result of the comparative analysis between user''''s perceived safety and visual preferences in each campus, the degree of perceived safety at ''''Closed'''' type was lower than that of ''''Open'''' type, but the degree of visual satisfactioni was higher at ''''Closed'''' type. 3. The factors affecting visual preference in campus were shown as density of wood, land form, and diverse type of the spaces. On the other hand, the factors affecting perceived safety were ''''enclosed space by wood'''' at the day time, and ''''the condition of lighting'''' at night. 4. Regarding gender differences in sensation of each space variables, female users showed higher satisfactio on the scenic beauty. 5. Regression analysis showed that general satisfation was determined by the variables such as ''''arrangement'''', familiarity'''', ''''cleanness'''', and ''''closed feeling'''', in Kyungbook Univ. And in Youngnam Univ. , the variables were ''''texture'''', ''''perceived beauty'''', ''''cleanness'''', and ''''complexity'''' respectively. 6. In conclusion, campus users wanted the outdoor spaces that have various land form and somewhat ''''open-closed'''' mixture type, which has a good ''''Edge Effect'''' to satisfy both aspects in safety and visual preferneces.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.2
• /
• pp.104-116
• /
• 1997

The purpose of this study is to grasp the characteristics of user's response to perceived safety and visual preferences for outdoor green spaces by the types of campus layouts. This research was investigated by color slide ratings and questionnaire survey to the students who are majoring in Landscape architecture in three universities locating at Taegu area. Two research sites have similarities in many ways but have differences in campus land form and design type such as 'Closed' and 'Open' types. Major results were summarised as follows ; 1. As a result of the slide test, the high degree of visual preference was shown in the campus that is 'Closed' type. However the degree of perceived safety was lower than that of in Youngnam Univ. campus. 2. According to the result of the comparative analysis between user's perceived safety and visual preferences in each campus, the degree of perceived safety at 'Closed' type was lower than that of 'Open' type, but the degree of visual satisfactioni was higher at 'Closed' type. 3. The factors affecting visual preference in campus were shown as density of wood, land form, and diverse type of the spaces. On the other hand, the factors affecting perceived safety were 'enclosed space by wood' at the day time, and 'the condition of lighting' at night. 4. Regarding gender differences in sensation of each space variables, female users showed higher satisfactio on the scenic beauty. 5. Regression analysis showed that general satisfation was determined by the variables such as 'arrangement', familiarity', 'cleanness', and 'closed feeling', in Kyungbook Univ. And in Youngnam Univ. , the variables were 'texture', 'perceived beauty', 'cleanness', and 'complexity' respectively. 6. In conclusion, campus users wanted the outdoor spaces that have various land form and somewhat 'open-closed' mixture type, which has a good 'Edge Effect' to satisfy both aspects in safety and visual preferneces.

• Journal of the Korean housing association
• /
• v.24 no.2
• /
• pp.69-76
• /
• 2013

With people leaving the countryside to the cities as a result of industrialization and urbanization and drastic reduction of school children due to low birthrate, nationwide, total 3,438 schools have been shut down following the closed schools policy. Consequently, local governments have been active in selling, utilizing, and leasing the closed schools but there are still 466 closed schools that need to be addressed quickly. In addition to this phenomenon, aging population has become an important issue, and demand for elderly welfare facilities population is also increasing as a result. However, the supply of welfare services remains inadequate. This study was conducted in an attempt to solve both local and social problems at the same time, caused by the closing of schools and an aging population, through the use of closed schools as elderly welfare facilities, and suggests plans for per-unit space according to its type, and prototype, through research analysis of practical use, based on case studies. With the conclusions of both advantages and disadvantages, drawn from its type, we are hoping to be able to use this study by adapting its type, or mixing, according to one's needs.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.3
• /
• pp.111-117
• /
• 2008

The aim of this paper was to investigate the fluid dynamic behavior of the automotive closed type water pump with balance hole in order to evaluate and justify its overall hydraulic performance and, in particular to analyze the effects of the balance hole on the reduction of hydraulic flow force of it. The analysis has been peformed by applying the commercial computational fluid dynamics (CFD) code, Fluent, to the solution of the 3-D turbulent flow fields of automotive closed type water pump. The reliability of the employed analysis was demonstrated by the comparison between numerical result and experimental data. Although, hydraulic head of the closed type water pump with 3mm diameter of balance hole decreased by 1.1%, axial flow force was effectively reduced by 13.3%, comparison of it with no hole at design point.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.12
• /
• pp.1169-1176
• /
• 2005

In this paper, thermal reliability of a closed type BLDC (Brushless DC) motor for high speed axial fan was analyzed by the accelerated life test. The closed type BLDC (Model No. MB1-8855-J01) motor was controlled by PCB module, which was composed of various electrical components. The failure of the closed type BLDC motor happened in PCB module due to high temperature. Failure mechanism of the closed type BLDC motor appears to be electrolyte dry out of capacitor. The accelerate life test was performed in temperature stress of $85^{\circ}C\;and\;105^{\circ}C$, respectively The failure data from the accelerated life test were analyzed and the life in each stress level was estimated with 960h and 261 h. At last, both life expression according to operating temperature of PCB module and life of the closed type BLBC motor in normal condition $(50^{\circ}C)$ were suggested.

• Archives of Craniofacial Surgery
• /
• v.23 no.3
• /
• pp.119-124
• /
• 2022

Background: Many severe nasal bone fractures present with septal fractures, causing postoperative septal deviation and negatively affecting the patients' quality of life. However, when a septal fracture is absent, it is difficult to predict whether surgical correction can help minimize nasal septal deviation postoperatively. This study determined whether performing closed reduction on even mildly displaced nasal bone fracture could deter the outcome of septal deviation. Methods: We retrospectively reviewed the data of 116 patients aged 21-72 years who presented at the outpatient clinic and emergency room with fractures of nasal bones only without any involvement of the septum from January 2014 to December 2020. Patients were classified into three fracture type groups: A (unilateral), B (bilateral), and C (comminuted with depression). The degree of septal deviation was calculated by measuring the angle between the apex of the most prominent point and the crista galli in the coronal view on computed tomography images. The difference between the angles of the initial septal deviation and that of the follow-up was calculated and expressed as delta (Δ). Results: Closed reduction tended to decrease the postoperative septal deviation in all fracture types, but the values were significantly meaningful only in type A and B fractures. In the surgical group, with type A as the baseline, type B showed a significantly larger Δ value, but type C was not significantly different, although type C showed a smaller Δ value. In the conservative group, with type A as the baseline, the other fracture types presented significantly lower Δ values. Conclusion: For all fracture types, closed reduction significantly decreased the extent to which the nasal septum likely deviated. Therefore, when a patient is reluctant to undergo closed reduction, physicians should address the possible outcomes and prognosis of untreated nasal bone fractures.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.9
• /
• pp.934-942
• /
• 2007

In this study, the characteristics of the load-sensitive hydraulic control system for closed center type of a wheel loader were analyzed using developed analysis program based on Amesim tool. From the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the system parameter effects on the controllable region and the pump pressure and load pressure variations were studied. The results were compared with the experimental ones. The results and discussions of the present paper could aid in the design of a load-sensitive hydraulic control system for closed center type.

• Archives of Craniofacial Surgery
• /
• v.21 no.1
• /
• pp.7-14
• /
• 2020

Background: It is difficult to completely fix nasal bone fractures with closed reduction, as it is often accompanied by septal cartilage damage, and this often results in postoperative secondary deformities. Thus, patients are often reluctant to undergo closed reduction surgery. The present study aimed to evaluate aesthetic and functional satisfaction, as well as satisfaction with and complications of closed reduction, according to nasal bone fracture type. Methods: The subjects were patients who underwent closed reduction under general anesthesia from January 2017 to December 2018. Based on the modified Murray classification, patients were classified into five groups according to the fracture site, septal fracture, and deviation. A total of 211 patients were sent a web-based survey on postoperative satisfaction and complications, as well as intention for revision and cosmetic surgery. Sixty-one patients (28.9%) responded. Results: There were no significant differences in aesthetic and functional satisfaction or satisfaction with closed reduction according to the fracture type, site, or severity. Postoperative functional complications developed in 14 of 61 patients (22.95%). With 10 out of 24 (41.67%) patients (p = 0.044), the bilateral fracture with septal fracture or prominent septal deviation type had a higher incidence of complications than the other types. Conclusion: The incidence of complications is higher for bilateral fracture with septal fracture or prominent septal deviation compared to the other nasal bone fracture types. Therefore, long-term follow-up after closed reduction surgery for this fracture type can aid in establishing additional postoperative treatment plans and improving patient satisfaction.