• Title/Summary/Keyword: short

Search Result 26,498, Processing Time 0.053 seconds

Behavior Analysis of Concrete Structure under Blast Loading : (II) Blast Loading Response of Ultra High Strength Concrete and Reactive Powder Concrete Slabs (폭발하중을 받는 콘크리트 구조물의 실험적 거동분석 : (II) 초고강도 콘크리트 및 RPC 슬래브의 실험결과)

  • Yi, Na Hyun;Kim, Sung Bae;Kim, Jang-Ho Jay;Cho, Yun Gu
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.5A
    • /
    • pp.565-575
    • /
    • 2009
  • In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.

Behavior Analysis of Concrete Structure under Blast Loading : (I) Experiment Procedures (폭발하중을 받는 콘크리트 구조물의 실험적 거동분석 : (I) 실험수행절차)

  • Yi, Na Hyun;Kim, Sung Bae;Kim, Jang-Ho Jay;Choi, Jong Kwon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.5A
    • /
    • pp.557-564
    • /
    • 2009
  • In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

Quality Characteristics of Prepared Rehmannia Root with Four Domestic Cultivars (국내 육성 품종별 숙지황의 품질 특성)

  • Kim, Yae Jin;Han, Sin Hee;Ma, Kyungho;Hong, Chung-Oui;Han, Jong-Won;Lee, Sang Hoon;Chang, Jae Ki;Lee, Jun soo;Jeong, Heon-Sang
    • Korean Journal of Breeding Science
    • /
    • v.51 no.4
    • /
    • pp.386-394
    • /
    • 2019
  • Rehmannia glutinosa, one of the major medicinal crops in Korea, can be classified into three types: fresh, dried and prepared Rehmannia root. In this study, the quality characteristics of prepared rehmannia root were evaluated using four different cultivars that are commonly used in the market. In making prepared rehmannia root, roots of Jihwang 1, Kokang, Togang, and Dagang were dried, soaked in rice wine, and steamed nine times. At each stage, physiochemical properties were analyzed, including yield, which is one of the most important industrial factors to consider. The yield was the highest in Togang at 23.61% and the lowest in Dagang at 21.16%. These yield values showed a highly negative correlation with the moisture content of roots. The fructose and glucose contents were increased during the 3rd, 4th and 5th steaming but then decreased. The sucrose, raffinose, and stachyose content gradually decreased during the first three steaming and were not detected during the 4th steaming. Additionally, the catalpol content was not detected after the 4th steaming. On the contrary, the 5-hydroxymethylfurfural content was not detected in the raw root but increased during the steaming. Jihwang1 and Togang exceeded the 0.1% Korean Pharmacopoeia standard after the 5th steaming, reaching it faster than did the other cultivars. Overall, Togang was the optimal cultivar considering the overall characteristics of its high yield and short steaming time. These results could provide useful information for the industrial use of prepared Rehmannia root based on the requirements and characteristics of each cultivar.

Analysis of Market and Technology Status of Major Agricultural Machinery (Tractor, Combine Harvester and Rice Transplanter) (핵심 농기계(트랙터, 콤바인 및 이앙기) 시장 및 기술 현황 분석)

  • Hong, Sungha;Choi, Kyu-hong
    • Journal of the Korean Society of International Agriculture
    • /
    • v.31 no.1
    • /
    • pp.8-16
    • /
    • 2019
  • Alternatives for increasing the competitiveness of locally manufactured agricultural machinery in domestic and foreign markets has been proposed. This was done by analyzing the major agricultural machinery's price and market share as well as their performance and quality. In the Korean domestic market, the market share of Japanese agricultural machinery has been identified to be 14.5% for tractors, 31.1% for combine harvesters, and 35.8% for rice transplanters, and on track for further increase. Japanese manufacturers' domestic patent shares are 58.5% for tractors, 79.9% for combine harvesters, and 69.8% for rice transplanters, showing the dire need for Korean domestic firms to expand their technological rights. To strengthen the industrial competitiveness of agricultural machinery, therefore, researches that develop the fundamental and elemental technology to reduce the frequency of breakdown should be needed in the short term. To achieve this, it is imperative to establish technology roadmap, promote greater cooperation between academia and industry, and systematically increase research funding. In addition, as a long-term solution for enhancing the competitiveness, an establishment of Agricultural Equipment Technology Institute is strongly recommended to systematically support R&D for developing core technologies, particularly high-quality components that guarantee durability and quality.

'Jungmo1033', a Derivative of High-quality Native Rice Variety 'Jagwangdo' (재래벼 '자광도' 유래 고품질 벼 '중모1033')

  • Jeong, Eung-Gi;Won, Yong-Jae;Ahn, Eok-Keun;Hyun, Ung-Jo;Cho, Young-Chan;Suh, Jung-Pil;Oh, Myoung-Kyu;Lee, Jeom-Ho;Hong, Ha-Cheol;Lee, Chung-Kuen;Jeon, Yong-Hee;Jeung, Ji-Ung;Chung, Hi-Che;Kim, Bo-Kyeong
    • Korean Journal of Breeding Science
    • /
    • v.51 no.1
    • /
    • pp.34-40
    • /
    • 2019
  • 'Jungmo1033', a japonica rice variety, was developed by the rice breeding team at the National Institute of Crop Science (NICS) in 1992. It is derived from a cross between a native variety 'Jagwangdo', which has translucent milled rice and medium maturity; and 'Hwayeong', which is an elite line with bacterial blight resistance and mid-late maturity. The heading date of 'Jungmo1033' was August 10 in the middle plain area of Korea, which was two days later than that of 'Hwaseong'. 'Jungmo1033' has a culm length of 79 cm, which was 5 cm shorter than that of 'Hwaseong', and 105 spikelets per panicle. 'Jungmo1033' showed resistance to bacterial blight (K1, K2, and K3 races) and stripe virus, but susceptibility to the K3a race of bacterial blight, dwarf and black-streaked dwarf viruses, and planthoppers. The milled rice of this variety exhibited translucency and a medium short grain shape. It had an excellent appearance and lower amylose content (19.1%) than that of 'Hwaseong'. The characteristics related to grain milling were better than those of 'Hwaseong', especially head rice milling recovery ratio and head rice ratio (94.8%). 'Jungmo1033' showed a milled rice productivity of 5.38 MT/ha at 11 sites under ordinary cultivation conditions. (Registration No. 5723)

A Study on Conceptual Suitability or Unfitness of 'Silhak' ('실학實學' 개념의 적합성 또는 부적합성에 관한 연구)

  • Kang, Jeong-Hoo
    • Journal of Ethics
    • /
    • no.88
    • /
    • pp.103-122
    • /
    • 2013
  • This paper aims to study on conceptual suitability or unfitness of Silhak(實學). It is general that by criticizing Chujahak(朱子學) or beyond the limitation of Seonglihak(性理學), Silhak has developed practical tendency to reforming the society in the middle and end of Chosen Dynasty, related to the context of Korean national reflection in modern times. However, it is unfortunate to be understood. As presented in Chosenwangjosillok(『朝鮮王朝實錄』), there has been a few usages in the term 'Silhak'. In short, it was different from its contemporary meaning. At that time, it was usually used to have the meaning of Gyunghak(經學), compared to Sajanghak(詞章學), or rarely, of 'the true study' or 'the practical study'. Therefore, it is to claim that its conception has been manipulated or exaggerated very seriously. Since 1930s, in particular, its conception has been misused in interpreting works of Jung Yak-Yong by some scholars, such as Jung In-Bo, Moon Il-Pyung and An Jae-Hong, who tried to apply the term to overcome the Japanese colonial era symbolised as modernity based on the future life of Korea. Even though their attempt has led to have crucial discussions on the conceptions of Silhak, it has an unnecessary result that there has been a new and totally different understanding of Silhak in South Korea, North Korea, China, Japan, etc., which means that the unsustainable conception of Silhak has been one of major problems in studying of Silhak. To give an practical solution, I would try to make sense of 'time spirit' whose scholars studied Silhak in the middle and end of Chosen Dynasty. A problem, however, is that a scholar group in the name of Bukhakpa(北學派) had certain links and bonds. This is because many scholars studying of Silhak were usually features out of the main stream, which made them it difficult to form any various groups. That is to say, it seems to be natural that they have dreamed of utopian imaginations less than of overlapping points in reality. To sum up, it would be concluded at least that any approach to human lives and thoughts in the given conceptions of Silhak, e.g. ethical thoughts of Silhak, enables us to be indifferentiated to take its true meaning and time spirit of Chosen Dynasty. To be disenchanted of its social roles in Chosen Dynasty, fundamentally, it should be escaped from the wrong net of illusions and sings in understanding Silhak in certain eclectic steps.

The Study of the Foundation of Establishing the Value of the Unification of the Korean Peninsula in Muliticultural Society of Korea -focused on a possibility of the mulitucultural conception of culture and emotion (한국 다문화 사회에서 한반도 통일의 가치정립의 토대에 대한 연구 -문화 개념과 정서 개념의 다문화적 접근의 가능성을 중심으로)

  • Song, Sun-Young
    • Journal of Ethics
    • /
    • no.80
    • /
    • pp.51-77
    • /
    • 2011
  • This study aims to explore how to establish any foundation of the value of the unification of the Korean Peninsula in multicultural society of Korea. Its main issue is related to Korean identity of a nation and its shared value among the mulitcultural members, in particular, of North Koreans including defectors, foreign workers, and immigrants of international marriage and their children. For this study, I would utilize a given research of the application of two concepts of culture to multicultural levels by criticizing its limit; as an alternative, furthermore, I would pay attention to the possibility of the concept of emotion in multicultural members. A short feature in a given study of two conceptions of culture in a multicultural society is as follows: the first is to regard it as the patterns of meanings and symbols, which is very useful to understand others or other culture; secondly, to see it as the lasting process of perfection in human life, which makes us recognize ourselves as a member, so to speak, identity. In application it to Korean muliticultural members, however, there are crucial and complicated problems according to the cases of their lives. For North Koreans, firstly, they tend to get the conception of Korean identity in terms of ideological policies and education of North Korean government. This means that they have a strong hatred towards the word multiculture, in the level of recognizing the self-culture. Secondly, North Korean defectors also have the recognition of the self-culture, but their serious problem is discriminative treatments by South Korean in terms of socio-economics, in the process of their settlement. Thirdly, parents and their children in multicultural family can have their identity as Korean. In parents, however, the level is double that they can have both identities of Korean as well as of their countries. The foundation, therefore, of the value of the unification in the Korean Peninsula is closely related to the issue of identity as Korean. To recognize it, it is possible only to consider and reflect all members' lives by applying the dual conceptions of culture to their multicultural lives. That is not of outer system, but of inner, relational and cultural emotion, which enables them to share their common value of unification.

A Study on the Policy Directions of Sports Welfare in Gangwon Province for Improving Quality of Life (삶의 질 향상을 위한 강원도 스포츠복지 정책방향 연구)

  • Kim, Heung-Tae;Kim, Tae-Dong
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.8
    • /
    • pp.411-424
    • /
    • 2019
  • The purpose of this study is to explore the feasible policy directions for sports welfare that can not only improve the standard of living through health but also ensure a happy and enjoyable life for the people of Gangwon Province. For this purpose, I have conducted studies such as the analysis on the sports class voucher project being implemented by the South Korean government and the case analysis in sports welfare, and present policy directions as follows. First of all, it is about upgrading the sports class voucher project. And as its implementation plans, I suggest ① increased publicity, ② the earmarking of the province's own budget for the sports class voucher project, ③ the establishment of a system for cooperation for work implementation between the related organizations and their staff in charge with a view to activating the sports class voucher project, and ④ the upgraded services for the sports class voucher project and the upgraded access to the life cycle-based universal welfare. Second, it is about using public sports facilities and developing various programs. I suggest the active utilization of the public sports facilities that enable people to learn the skills for such sports disciplines as baseball, badminton, ice sports, and golf and the development and distribution of distinctive educational programs for dance for media entertainment shows for female youths, climbing, cheer leading, fencing, surfing and horseback riding. Third, it is about nurturing the human resources and networking. For this, I suggest the creation of 'Sports Welfare Specialist Training Program' and the training of the college students majoring in sports science with the aim of creating a number of jobs. Fourth, it is about refurbishing the system and establishing the support system. I suggest the dismantling of the partitions in the welfare policy related to sports activities and the formation of (tentatively named) 'Gangwon Province Sports Welfare Implementation Committee', and the creation of (tentatively named) 'Sports Welfare Project Support Team' in Health, Welfare & Women's Affairs Bureau or Culture, Tourism and Sports Bureau in the short term and then its long-term expansion into (tentatively named) 'Gangwon Province Sports Welfare Support Center' in responding to the needs that reflect the provincial demographics, with a view to establishing a single lineup for the administrative support system. Furthermore, as budget and manpower are needed to realize customized sports welfare that suits the characteristics of the province and in which all the provincial residents can collect benefits, I suggest that the province provide the legal basis through creating 'Ordinance Promoting Sports Welfare in Gangwon Province' and pushing forward with (tentatively named) 'Gangwon Province Sports Welfare Competition' as what revises the sports class voucher project for the purpose of broadening the basis for sports welfare promotion.

Effects of Visiting Prehabilitation Program against Functional Decline in the Frail Elderly: A Prospective Randomized Community Trial (허약노인을 위한 방문재활 프로그램의 장애발생예방 효과에 대한 연구)

  • Kim, Chang-O;Lee, Heeyeon;Ho, Seung Hee;Park, Hyunsuk;Park, Chulwoo
    • 한국노년학
    • /
    • v.30 no.4
    • /
    • pp.1293-1309
    • /
    • 2010
  • This study is aimed to evaluate the effects of community-based prehabilitation program developed to prevent functional decline in the frail elderly and to provide a basis to practically operate this program in the public health care service. From March to August 2009, 110 frail elderly people were recruited among the registered participants of the home visit program in Korea to perform a prospective randomized community trial. We randomly assigned these people into two groups. One group (n=50) participated in the visiting prehabilitation program for 3 months focusing on improving their muscle strength of upper and lower limbs, walking ability, and balancing. The other group (n=60) underwent our visiting fall prevention program for control. To assess the effectiveness of prehabilitation program, physical functioning (PF) and short physical performance battery (SPPB) were measured for the primary outcomes and also some other indicators: exercise performance, nutritional status, emotional functioning, experience of admission, and events of fall. As a result, significant improvements of geriatric functional status were noticed among the participants. After 3 months, PF increased by 1.3 ± 3.8 points in prehabilitation group and decreased by 1.1 ± 5.4 points in controls (p=.020). SPPB improved by 2.4 ± 2.0 points in prehabilitation group and increased only 0.3 ± 1.5 points in controls (p<.001). Significant effects were also shown in their exercise performance tests and emotional status, the number of multiple falls, and the experience of functional decline after the fall (p .002-.038). Visiting prehabilitation program is safe and effective program for frail older adults. Thus, it is strongly recommended to universally adopt this program to prevent functional decline in the frail elderly.

Responses of Health Physical Fitness and Arterial Stiffness through Cigarette Smoking (흡연습관이 성인 남성의 건강관련체력 및 동맥경직도에 미치는 영향)

  • Jung, Min-Kyung;Park, Eun-Kyung;Yoo, Jae-Hyun
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.2
    • /
    • pp.197-205
    • /
    • 2019
  • This study was to compare arterial stiffness and hemodynamic responses between male smokers and non-smokers. This study also investigates the influences of smoking before exercise on arterial stiffness and hemodynamic responses. 24 male subjects of age 20-29 without history of cardiorespiratory disease were divided into smokers and non-smokers. Smokers had more than 5 years of smoking experience. In order to evaluate the effects of pre-exercise smoking, smokers were tested twice, once with a cigarette before the exercise and the other once without one. Data was collected from bio-impedance analysis, SphygmoCor XCEL, graded exercise test, and fitness test. Main results of this study are as follows: First, there are differences between smokers and non-smokers in cardiorespiratory and hemodynamic response functions, as shown by maximal oxygen consumption, exercise duration, and heart rate. Second, the although the arterial stiffness between smokers and non-smokers showed statistically significant differences in the speed of the pulse wave velocity and augmentation index, smoker had a faster rate. It shows that smoking behavior has a negative impact on the cardiovascular system. Third, pre-exercise smoking behavior does have an impact on cardiorespiratory and hemodynamic response functions, as shown by exercise duration and heart rate. Lastly, arterial stiffness between smokers and non-smokers showed statistically not significant in the speed of the pulse wave velocity and augmentation index. However, the difference was not statistically significant. Brachial systolic pressure, a component of pulse wave analysis, on the other hand, was significantly dependent on pre-exercise smoking behavior. Subjects who participated in this study are college students in early 20s. Given their relatively short history of smoking, it is possible that their smoking habits are not severe enough to develop into cardiorespiratory or cardiovascular diseases. But Smokers showed lower levels of cardiopulmonary functions, as maximal oxygen consumption and exercise duration than nonsmokers.