• Title/Summary/Keyword: centering ratio

Search Result 93, Processing Time 0.026 seconds

The Nonlinear Behavior Characteristics of the 3D Mixed Building Structures with Variations in the Lower Stories (입체 복합구조물의 하부골조 층수 변화에 따른 비선형 거동특성)

  • 강병두;전대한;김재웅
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.6 no.1
    • /
    • pp.55-62
    • /
    • 2002
  • The upper wall-lower frame structures(mixed building structures) are usually composed of shear wall structure in the upper part of structure which is used as residential space and frame structure in the lower part of structure which is used as commercial space centering around the transfer system in the lower part of structure. These structures are characteristics of stiffness irregularity, mass irregularity, and vertical geometric irregularity. The purpose of this study is to investigate the nonlinear response characteristics and the seismic capacity of mixed building structures when the number of stories in the lower frame is varied. The conclusions of this study are following. 1) As the result of push-over analysis of structure such as roof drift(i.e. roof displacement/structural height) and base shear coefficient, when the stories of lower frame system are increased, base shear coefficient is decreased, but roof drift is increased. 2) According to an increase in stories of the lower fame, story drift and ductility ratio of upper wall system are decreased and behavior of upper wall system is closed to elastic. 3) When the stories of lower frame system are increased, the excessive story drift is concentrated on the lower frame system.

A study on the Analysis of Locational Characteristics of REITs Assets (운영부동산 유형별 리츠자산의 입지특성 분석에 관한 연구)

  • Jung Jaeyeon;Lee Changsoo
    • Journal of the Korean Regional Science Association
    • /
    • v.40 no.1
    • /
    • pp.89-110
    • /
    • 2024
  • REITs are very closely related to real estate management, but there have been no prior studies analyzing the location of REITs assets. Therefore, this study analyzed the location characteristics of REITs assets in two aspects to clarify the location characteristics by using spatial information of REITs assets. First, the characteristics of the type of city where REITs assets are distributed were analyzed, and second, the characteristics of the zoning where REITs assets are distributed were analyzed. As a result of analyzing the characteristics of the city where REITs assets are distributed by type, it was analyzed that in the case of the capital area, both the ratio of cities with REITs assets location and the intensity of REITs assets location (number of REITs assets per city) have location characteristics by city hierarchy in the order of metropolitan city > big city > small and medium-sized city. In the case of non-capital area's metropolitan and large cities, the ratio of REITs assets location cities is similar to that of the capital area, but the location intensity of REITs assets was analyzed to be significantly lower than that of the capital area. As a result of the analysis of REITs assets by type, housing REITs assets tend to be located in the old downtown commercial zoning and the new downtown residential zoning, office REITs assets are characterized by concentration of location in specific commercial zoning of Seoul, and retail REITs assets are located mainly in the old downtown station area. In addition, it was found that logistics REITs assets tend to be located in management zoning, centering on key logistics hub cities in the region.

Assesment Of Image Quality in the Abdominal Magnetic Resonance Imaging: Comparison with 1.5 T and 3.0 T (복부 자기공명영상에서 영상의 질 평가: 1.5 T 와 3.0 T 비교)

  • Goo, Eun-Hoe
    • Journal of the Korean Society of Radiology
    • /
    • v.10 no.5
    • /
    • pp.367-373
    • /
    • 2016
  • This study conducted an analysis to compare the differences in the properties of the magnetic field and the generation of artifacts because of the difference in the magnetic field between 1.5 T equipment and 3.0 T equipment, centering around four types of pulse sequences, mainly applied to the abdominal Magnetic Resonance Imaging (MRI). With data on 500 persons transmitted to the PACS, this study analyzed the SNR value, quantitatively and carried out a qualitative evaluation, dividing MSA, CSA, and DA into three steps. As a result of the quantitative evaluation, the SNR value was significantly higher in the 1.5 T equipment; however, there was a factor deteriorating the image quality, too, as artifacts were generated in the images. The 1.5 T equipment generated fewer artifacts than the 3.0 T equipment did, so it could compensate the image quality for 3.0 T. In conclusion, based on these findings, this study could understand the differences in the properties of the magnetic field and the generation of artifacts occurring because of the difference in the magnetic field and could provide a measure for them. This study would be guidelines for MRI users who directly examine the patients in abdominal MRI using the two types of equipment in the clinical setting in the future.

Seismic Behavior and Estimation for Base Isolator Bearings with Self-centering and Reinforcing Systems (자동복원 및 보강 시스템과 결합된 면진받침의 지진거동과 평가)

  • Hu, Jong Wan
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.35 no.5
    • /
    • pp.1025-1037
    • /
    • 2015
  • Flexible base isolation bearings that separate superstructure from ground have been widely used in the construction field because they make a significant contribution to increasing the fundamental period of the structure, thereby decreasing response acceleration transmitted into the superstructure. However, the established bearing devices installed to uphold the whole building give rise to some problems involved with failure and collapse due to lack of the capacity as modern structures are getting more massive and higher. Therefore, this study suggests new isolation bearings assembled with additional restrainers enabled to reinforcing and recentering, and then evaluates their performance to withstand the seismic load. The superelastic shape memory alloy (SMA) bars are installed into the conventional lead-rubber bearing (LRB) devices in order to provide recentering forces. These new systems are modeled as component spring models for the purpose of conducting nonlinear dynamic analyses with near fault ground motion data. The LRB devices with steel bars are also designed and analyzed to compare their responses with those of new systems. After numerical analyses, ultimate strength, maximum displacement, permanent deformation, and recentering ratio are compared to each model with an aim to investigate which base isolation models are superior. It can be shown that LRB models with superelastic SMA bars are superior to other models compared to each other in terms of seismic resistance and recentering effect.

Housing Need and Demand Assessment: Focused on Public Housing Development Projects (공공주택 사업지구의 수요평가모델 구축 연구)

  • Ji, Kyu-Hyun;Lee, So-Young;Kim, Yong-Soon
    • Land and Housing Review
    • /
    • v.5 no.4
    • /
    • pp.247-257
    • /
    • 2014
  • This study proposes a new housing need and demand assessment model centering on small-scale housing development projects and happy house development projects that reflected the recent changes in rental and small sized apartment centered public housing policies and development paradigms. The housing need and demand assessment model of public housing development projects consists of quantitative evaluation factors such as potential need indicator and demand pressure indicator and qualitative evaluation factors such as local condition indicator. The potential need indicators of small sized housing development projects are calculated by subtracting the stock of already-supplied constructed rental and purchased rental housings from the potential quantity of need drawn from the small regions such as -eup, -myeon, and -dong. In the potential need indicators of happy house development projects, the potential need is calculated from those who are expected to receive a happy house in the unit of -si, -gun, and -gu. In small-sized housing development projects, demand pressure indictors are the number and the proportion of those who opened a subscription deposit, the number of those who received basic livelihood security and the number of those who were patriots and veterans. The demand pressure indicators of the happy house development projects are stock ratio of small-sized houses, rate of rise in housing rent price, level of housing rent price, and rate of monthly rent house.

Monitoring of Particulate Matter Concentration for Forage Crop Cultivation during Winter Season in Saemangeum (새만금 내 동계 사료작물 재배에 따른 미세먼지 농도 변화 모니터링)

  • Lee, Seong-Won;Kang, Bang-Hun;Seo, Il-Hwan
    • Journal of Bio-Environment Control
    • /
    • v.31 no.2
    • /
    • pp.114-124
    • /
    • 2022
  • The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

Firms' Switching Intention to Cloud Based Digital Trade: Perspective of the Push-Pull-Mooring Model

  • In-Seong Lee;Sok-Tae Kim
    • Journal of Korea Trade
    • /
    • v.26 no.6
    • /
    • pp.20-40
    • /
    • 2022
  • Purpose - In recent times, the international trade environment has been changing rapidly, centering on the online market. In the post-COVID-19 era, small and medium-sized trading companies are facing the problem of not being properly provided with overseas market research, market trend analysis, and trade-related information. Cloud-based digital trade is being sought as an alternative to solve these problems; however, there is a lack of research on the intention to switch to digital trade among small and medium-sized trading companies. Therefore, this study empirically analyzes the intention to switch to digital trade based on the migration theory, and through this, attempts to identify each factor that affects the intention to switch to digital trade. Design/methodology - In this study, in order to identify factors influencing intention to switch to digital trade and innovation resistance of small and medium-sized trading companies, through previous research on migration theory and the PPM (Push, Pull, Mooring) model, each variable was selected for the purpose of the study. Based on this, a research model was established for the factors affecting switching to digital trade of small and medium-sized trading companies and empirically analyzed. In addition, considering the differences in the innovation propensity and maturity of information infrastructure of trading companies as the recipients of innovation, this study analyzes the moderating effect of the mooring effect and seeks ways to establish specific strategies according to the degree. Findings - As a result of empirical analysis, the pull effect was found to have the greatest influence on intention to switch to digital trade. However, the pull factor was found to have an effect on user resistance, and it was confirmed that it was a factor simultaneously inducing positive and negative consumption behaviors among users. In addition, it was found that the higher the company's innovation propensity, the higher the pull effect's influence on the intention to switch, and analysis showed that the push effect had no influence. In addition, companies with high information infrastructure maturity were expected to have a relatively high level of intention to switch compared to companies with low information infrastructure maturity, and the difference between the two groups was found not to be statistically significant. Originality/value - This study is a timely study in that it demonstrated the effect on the switching to cloud-based digital trade for small and medium-sized trading companies and that the cloud system related to digital trade is in full swing. There are academic implications in that it revealed that the pull effect is an important factor in the intention to switch to cloud service. Practical implications were presented in that small and medium-sized trading companies suggested ways to increase the value of the cloud system for switching to digital trade and a way to increase the switching ratio by minimizing the mooring effect. In addition, the study argues that active institutional support from the government is needed to activate cloud service.

Department of Preventive Medicine and public Health, College of Medicine, Chungnam National University (일부 농촌지역 주민들의 사지 부자유 실태 및 우울과의 관련성)

  • Song, Sun-Hui;Cho, Young-Chae
    • Journal of agricultural medicine and community health
    • /
    • v.30 no.1
    • /
    • pp.63-74
    • /
    • 2005
  • Objectives: The present study aimed to provide the fundamental data for guiding establishment of measures among the rural elderly population with physical disabilities. The specific goals of this report are to reveal the prevalence of their disabilities, its tendency according to their increasing age, and to assess the background explanations. Methods: The self-administered questionnaires have been performed 432 persons of rural residents age 40 and greater in Kumsan-Gun and Chongyang-Gun, Chungchongnamdo Province. The questionnaire items included presence or not. of disabilities. specific causes for disabilities, anthropometric measures, and amount of physical activities. Results: The proportion of disabilities was higher in women than men, and the functional degree of their limbs decreased with the increasing age. The proportion of disabling extremities was higher in the lower extremities than in the upper ones. Joint diseases were the most prevalent causes for disabilities of extremities. Concerning the degree of depression, 41.2% of study subjects were normal, 47.5% had mild depression, 6.3% moderate, and 5.1% severe depression, with no statistical difference based on age and sex. The worse are the functional degree of both extremities, the greater the degree of depression the subjects had. The odds ratio for presence of disabilities of extremities was 2.6 times higher in women than in men for sex and for age, 50's were 3.5 times, 60's 4.3 times, 70's 4.9 times than 40's, respectively, with increasing tendency with increasing age. The odds ratio for depression was 1.2 times greater in subjects with disabilities than in normal population with no statistical difference. Conclusions: More efforts are needed to establish elderly specific measures for providing proper public health services centering on maintenance of physical functioning among elderly population.

  • PDF

A comparative study between Korea and the USA on the development process in retail trade & its changing locations (소매업의 발달과정과 입지 변화에 관한 한.미 비교 연구)

  • Jeon, Kyung-Sook
    • Journal of the Korean association of regional geographers
    • /
    • v.6 no.2
    • /
    • pp.21-40
    • /
    • 2000
  • The retail trades in many countries have changed recently according to the high quality, diversification, and marked individuality of consumer needs. Under the continually competing system of the WTO agreement, corporations based in the USA and the EU try to raise their market share in other countries so it is inevitable for Korean retail enterprises to compete with them. This paper is aimed at contributing to the efficient growth for Korean retail trade from the analysis of the development process in retail trade and its changing locations comparing Korea and the USA. Retailers in the USA have practiced diversified marketing strategies considerably in order to survive in a rapidly changing retailing environment. American retailing, which has the most advanced marketing system in the world, has been of growing concern to marketing strategies in Korea. The following is a brief summary of this study. 1. Speedy and higher quality consumption is needed in accordance with the great increase in the single-family household and the female labor force participation both in Korea and in the USA. Senior citizens have become a new consumer group due to the aging population. In the future the retail trade will switch over to diversified retail formats and internet shopping as countries are transformed into information and communication societies. 2. In Korea, the former retail system characterized by markets and department stores has been greatly changed since the late 1980s with emphasis on high quality and convenience in consumption behaviors, with large domestic enterprises and foreign distribution corporations participating in Korean retailing. In the USA, retailing mergers and takeovers by major retails, bankruptcies, and extra-large shopping centers have emerged since the late 1980s. Recently, the USA retailing formats have been changed from the lower price-oriented discount types to the large scale theme parks. Much emphasis was put on entertainment, resorts, and convention centers. On the other hand, non-store types, such as the internet shopping, the CATV shopping, as well as catalog and mail-order sales are drastically increasing, although the proportion of their sales is low up to now. 3. In Korea, most of the retail facilities are concentrated in Seoul and the Metropolitan Region, and the distribution ratio of facilities came to 52% in 1997. The periodic markets, traditional markets which open on a periodic basis, are located mainly in Chollanam-do and Kyungsangbuk-do. The large-sized discount stores have expanded their locations to the over-crowded apartment complexes in new towns, located in the Metropolitan Region, and the large provincial cities, unlike the suburban locations in the USA. Therefore we needed to give attention to the locational relations in retail facilities between Seoul & the Metropolitan Region and rural settlement areas. In the USA, urban areas grew quickly with the development of the automobile in the 1920s, and the location of stores changed from a dispersed style centering around rural areas to a centralized one in urban areas. There is an accelerated growth for suburban areas, which have grown rapidly since 1950. As the membership warehouse clubs were introduced in the 1970s, the decentralization of location was more intensified. On the other hand, inner cities were revitalized by rearranging existing facilities to cope with suburban areas. And the location-free virtual retailing & TV shopping are also growing every year. 4. In view of the above, the continuous and desirable development devices in Korean retail trade are summarized as follows: First, the countermeasures against economies of scale, increase in retailing sales, and rise of a employment percentage in retailing are in need. Second, a scheme of lowering the proportion of food retail sales, and increasing a ratio of durable goods sales need to be worked out. Third, the original ideas are needed to apply positively information, communication and technology to retailing, to graft the traditional types on modem ones based on the social culture. Fourth, strategies are needed to strengthen the competitiveness of our retail trade through cooperation and chains of smaller retailers, the large enterprises participating in the distribution industry. Fifth, in order to realize the above, the retail industry, the administration, and the academic world should support the retail segment with concern and a practical strategy plan.

  • PDF

Research on the Size, Formation and Tendency to Evade the Road of the Feeding Flocks of Crane Species - Centering on the Effect of Road vs. Traffic Condition - (두루미류의 취식무리 크기 및 구성과 도로에 대한 회피 - 도로의 영향 vs 통행에 의한 영향? -)

  • Yoo, Seung-Hwa;Lee, Ki-Sup;Kim, In-Kyu;Kang, Tae-Han;Lee, Han-Soo
    • Korean Journal of Environment and Ecology
    • /
    • v.23 no.1
    • /
    • pp.41-49
    • /
    • 2009
  • This research conducted a survey on the feeding crane's size, formation and distribution distance subsequent to road pattern and feeding flock's size during the wintering season eight times at the Cheolwon basin in Korea from December 2005 until February 2006. The survey results are as follows: First, the feeding flocks of the Red-crowned and White-naped Crane were found to mainly consist of two to four individuals. Mono-specific feeding flocks were more identified than hetero-specific feeding flocks in both Red-crowned and White-naped Cranes. There existed a significant difference in the ratio by size between the feeding Red-crowned and White-naped Cranes. The crane's average distribution distance from the paved road was much farther than from the unpaved road, paved farm road and unpaved farm road. In case of the white-naped crane, there was a difference in its distance length from between the road and farm road and there existed a significant difference only in the paved road in the distance length by road pattern between these two bird species[Red-crowned and White-naped Crane]. Such a result indicates that crane species don't prefer the road with frequent vehicular traffic to the road with low vehicular traffic. 5 or more individuals of feeding flocks of the Red-crowned Crane were located at a farther distance length from the paved road comparing to less than 5 individuals of the whole feeding flocks and less than 5 individual feeding flocks. 5 or more individuals of feeding flocks of the White-naped Crane were located at a farther distance length from the paved road, paved farm road and unpaved farm road than less than 5 individuals of feeding flocks of the White-naped Crane; however, there existed no difference in distance length subsequent to their group size. Conclusively, it was found out that the flocks with a larger size were more greatly affected by interrupting factors. Considering such results, there seems to be a more relation to the fact that larger size feeding flocks of crane species have a higher efficiency in the lookout for their surroundings.