• Journal of Korean Society of Steel Construction
• /
• v.13 no.1
• /
• pp.9-18
• /
• 2001

many steel tubular truss as roof structures are used of the large span structures Steel tubular sectioned truss has the structural merits in compared with other sections such as H, L-shape sections However it occurs local buckling at the joint of branch in truss and it makes the deterioration of loading capacity Loading capacity and deformation characteristics of truss joints are very complicate so it is very hard to predict exact solution of them Therefore this thesis dealt with T-type joints of steel circular hollow sectioned truss. A series of experimental scheme were planned and mainly experimental parameters were : ratio of diameter of branch-diameter of main chord(d/D). diameter-thickness(T/D) of main chord. In this paper predicted yield load capacity using by closed ring analysis method additionally compared with that of suggested by closed ring analysis method additionally compared with that of suggested by other countries.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.8 no.1
• /
• pp.23-29
• /
• 2010

Purpose : This study is to offer clinical primary data that examines the change of imaging structure and the quantitative evaluation of muscle activity on myofascial trigger points. This study examines neuromuscular physiological characteristic by comparing the differences in physical findings, pressure pain threshold, imaging, and electrophysiological characteristics in latent and active myofascial trigger points muscle and normal muscle through the following experimental procedures. Methods : The participants for the study were thirty-three adults in their twenties. We divided three groups into normal, latent and active myofascial trigger points groups by physical findings. We analyzed the results of measured pressure pain, threshold for pain, ultrasound imaging perform for structure characteristic of muscle, surface EMG according to type of muscle contraction for function of muscle contraction. Results : Significant differences were indicated in pressure pain threshold (p<0.05). Significant differences were discovered in the ultrasound imaging analysis. There were increases in muscle Echogenicity white area index (p<0.001). There were significant differences that decrease in %MVIC (p<0.05), increase in MDF (p<0.05). Conclusion : From these results, active rnyotascial trigger points muscle showed quality deterioration on ultrasound imaging and decreased function of muscle contraction, increased motor unit action potential of II type fiber, and electrophysiologically. Imaging structure and neuromuscular physiological characteristic can be diagnostic and quantitative analytical techniques for myofascial pain syndrome and a primary factor that reflected in physical therapy intervention.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.1
• /
• pp.60-70
• /
• 2007

Statement of problem: The cement-type abutment would be needed for the reduction of its body in order to correct the axis and to assure occlusal clearance. In the case of intraoral preparation, there is a potential risk that generated heat could be transmitted into the bone-implant interface, where it can cause deterioration of tissues around the implant and failed osseointegration. Purpose: The purpose of this study was to assess the difference of the heat transmitting effect on external and internal connection implant types under various conditions. Material and method: For evaluating the effects of alternating temperature, the thermocoupling wires were attached on 3 areas of the implant fixture surface corresponding to the cervical, middle, and apex. The abutments were removed 1mm in depth horizontally with diamond burs and were polished for 30 seconds at low speed with silicone points using pressure as applied in routine clinical practice. Obtained data were analyzed using Mann-Whitney rank-sum test and Wilcoxon / Kruskal-Wallis Tests. Result: Increased temperature on bone-implant interface was evident without air-water spray coolant both at high speed reduction and low speed polishing (p<.05). But, the difference between connection types was not shown. Conclusion: The reduction procedure of abutment without using proper coolant leads to serious damage of oral tissues around the implant irrespective of external and internal connection type.

• Journal of Korean Society of Forest Science
• /
• v.98 no.2
• /
• pp.156-162
• /
• 2009

Nebkhas are widely distributed in farming-pastoral zones, typical grassland and desert margins. In the southeast of the Inner Mongolia Plateau, it is mainly distributed at the leeward of cultivated land and alluvial fan, severe deterioration rangeland and around residential points. Through the field measurement and statistical analysis of Caragana microphylla Lam. Nebkhas morphological parameters (length, width and height of Nebkhas are included), the results show that there were close correlations between the Nebkhas morphological parameters. The ranges of height and width of Nebkhas changed dramatically and have reached up to 11.44 m and 7.97 m respectively, however, the change range of height was relatively smaller and just 1.09 m. The morphological parameters change of the same type Nebkhas in the same region was large ranging from 0.56 m in height, 3.56 m in width to 6.96 m in length, while the morphological characteristics of the same type Nebkhas in different regions were much similar. A correlation between length and width was significantly positive, but the correlations between height and length, and between height and width were much more complicated. It can be concluded that the Nebkhas in Zhengxiangbai Banner and Taipusi Banner were at the initially growing stage, while the Nebkhas in Huade County belonged to a transitional stage from the growing phase to the stabilizing phase. The changing regularity of distance between Nebkhas in along-wind direction was not consistent.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.8 no.3
• /
• pp.169-176
• /
• 2004

The Mechanistic model, considering expansion stress, coefficient of diffusion etc. to time, is applied to predict the deterioration of concrete structures of the nuclear power plant(NPP) due to sulfate attack. Mix design for the test was three kinds of specified compressive strength 385, 280 and $210kgf/cm^2$ which are used to construct NPPs and cement was type I and V. The immersion test was performed with 10% $Na_2SO_4$ solution to cement type and strength for a year. The coefficient of diffusion on each concrete mix is calculated based on the results of immersion test, and it is used for predicting the sulfate attack of the concrete structures of NPP. The coefficient of diffusion of the target concrete ranged $0.5763{\sim}3.9002{\times}10^{-12}m^2/sec.$, and the sulfate attack rate of concrete structures of the NPP was predicted as 0.1~7.1 mm/year.

• Korean Journal of Human Ecology
• /
• v.19 no.6
• /
• pp.1031-1044
• /
• 2010

Corresponding to the rapid growth of the aging population without an adequate social safety net for the elderly, older people face great disadvantages due to sudden illness or poor health and a lack of support from the younger generation. Furthermore, older women are suffering from a drastic deterioration of their economic status because of insufficient retirement savings. Examining the impact of labor force participation and living arrangement on health status and life satisfaction in later life, it is important to consider gender differences in context of social policies for the elderly. Using data based on a stratified national sample of the elderly by the Korean Longitudinal Study of Aging (KLoSA), multiple regression model were used to estimate the relationships between labor force participation and health status and subjective life satisfaction concerning the quality of their later life. The result indicates that good health status and high level of life satisfaction are associated with the type of paid work status for the elderly men, but those are associated with the type of non paid work, such as family businesses employees for the elderly women. Significant differences in chronic health condition and subjective life satisfaction by employment characteristics are found among the elderly. In addition, older women's high level of life satisfaction was associated with the participation of the social activity. The major conclusion from these results should help us understand gender differences in the elderly and acknowledge further exploration of gender variations in these people's later life.

• Journal of the Korean Institute of Educational Facilities
• /
• v.5 no.1
• /
• pp.33-43
• /
• 1998

With increased social participation of married women and with the notion of importance of pre-school childhood on human development, the importance of nurseries is being emphasized. The transformation of the traditional family system into a nuclear family system and the deterioration of the traditional child education have also put nurseries as a primal social interest. But, at present, at the end of 1994, only 10% of the children have benefitted from such facilities, the supply not being able to meet demand. Also, the spatial organization and the management of such facilities has been unsatisfactory. In this perspective, this study aims to grasp the present condition of nurseries, to investigate and analyse case studies, to suggest standards and reform measures, and based on these, to produce basic information for the formation of an architectural spatial model. We've selected investigation of present conditions and case studies, interviews, and observation as investigative methods and through these we've assessed tangible spatial planning and spatial proportion by parts. 1. The most preferred grouping method is toddler/preschooler type, and the group size and staff-to-child ratios vary according to the children's age 2. The younger children's activity rooms are located in the lower level, and the activity room of the children on the similar development stages are located adjacent to one another 3. Most of the facilities do not have the public spaces(indoor playrooms, dinning rooms, napping rooms, bathrooms, sickrooms) For dinning and napping, activity rooms are being used, and for sickrooms, director's room or staff rooms 4. As for the correlations of the spaces(home bases, activity rooms and its outdoor spaces, day-care-centers and its community), closed plan type is 90% over, and modified open plan is 10% min.

• Journal of the Korea Institute of Building Construction
• /
• v.21 no.4
• /
• pp.377-386
• /
• 2021

In April 2019, this study was enacted as a test method for the performance of waterproof layers in an environment where complex deterioration and structural behavior are simultaneously applied, but some existing standards were implemented to point out the errors of the method that should be supplemented. Thus, in establishing standards for (tentative) adhesive waterproofing sheets, field workability and quantification of test results were studied on the structural behavior response performance test methods included as test items. In addition, the performance evaluation of adhesive-type composite waterproof sheets was conducted based on the considered contents to review improvements such as applicability as an item of standard standards and field workability related problems.

• Journal of the Korean Electrochemical Society
• /
• v.25 no.3
• /
• pp.119-124
• /
• 2022

Because high power with large size cell is used for the battery pack of hybrid electric vehicles and electric vehicles (HEV and EV), average temperature in a battery cell is the important criteria of the thermal management of the battery pack. Furthermore, fast charging technology is required to reduce battery charging time. Since battery pack performance and lifespan are deteriorated due to the heat of cells and electronic components caused by fast charging, an effective cooling system is required to reduce performance deterioration. In this study, a cooling system and module design applied to a pouch-type for fast charging battery cell are investigated, and the cooling performance that can maximize the efficiency of the battery was analyzed. The result shows that the vapor chamber cooling system has better cooling performance, the temperature drop in the module was 5.82 ℃ compared with aluminum cooling plates.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1997.06a
• /
• pp.207-231
• /
• 1997

The use household water purifier is continuously increasing due to the distrust of the piped, rap water, which may be caused by the deterioration of water quality and water supply facilities in Korea. The water purifier distributing in the domestic market is the membrane type that composes of membrane as a basic filter, sediment filter as a prefilter and activated carbon filter instead of one purifying water system. The membrane type using as a water cleaning system is mainly the method of micro filtration(NIF) as well as ultra filtration(UF) and reverse osmosis(RO). The types of MF and UF are using to remove suspended solids and virus, and RO is using to remove ionic compound in chemical organic compounds. At the beginning the household water purifier was imported as end-product or assembled by only importing module from small businesses in Korea. Therefore, people was hard to confide in the product quality because the sales policy and management of water purifier by small business were not effectively organized. However, the defects of water purifier having up to now ate improving by the efforts of special branches of water purifier and large enterprises, and new great products are developing and producing. To develop the best quality product of water purifier in Korea, it should be considered seasonal water characteristrics rather than any other condition. For example, the water purifier can be affected by the water temperature change, increase of suspended solids in the rainy season and inflow of raw water having concentration in a dry season. The subject we have to investigate in the future is to develop the water purifying system adaptable in Korea which can treat the water quality using close analyses of local and seasonal water characteristics.