• Title/Summary/Keyword: Ultimate Capacity

Search Result 1,200, Processing Time 0.031 seconds

An Experiment on Redundancy in Continuous Span Two-Girder Bridge - Effects of Lateral Bracing (연속 2-거더교의 여유도 평가 실험 - 수평브레이싱의 효과)

  • Park, Yong-Myung;Joe, Woom-Do-Ji;Hwang, Min-Oh;Yoon, Tae-Yang
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.4A
    • /
    • pp.417-429
    • /
    • 2008
  • This paper presents an experimental result to evaluate the redundancy in continuous span two plate-girder bridges which are generally classified as a non-redundant load path structure. The experiments were performed when one of the two girders is seriously cracked. To estimate the effects of bottom lateral bracing on the redundancy, the experiment variable was considered as the bottom lateral bracing, and two 1/5-scaled bridge specimens with and without lateral bracing system were fabricated. The ultimate loading tests were conducted on the damaged specimens with an induced crack at a girder in the side span. The test results showed that the load carrying capacity of damaged specimen with bracing was about 1.2 times higher than that without bracing. To evaluate the redundancy in each specimen, numerical analysis was performed to calibrate the difference of dead load between the actual bridge and the test specimens. When the dead load calibration is considered, the results showed that a continuous span two-girder bridges have a reasonable redundancy even without lateral bracing. Especially, the level of redundancy is increased by about 1.8 times when the lateral bracing is provided.

Mechanical properties of new stainless steel-aluminum alloy composite joint in tower structures

  • Yingying Zhang;Qiu Yu;Wei Song;Junhao Xu;Yushuai Zhao;Baorui Sun
    • Steel and Composite Structures
    • /
    • v.49 no.5
    • /
    • pp.517-532
    • /
    • 2023
  • Tower structures have been widely used in communication and transmission engineering. The failure of joints is the leading cause of structure failure, which make it play a crucial role in tower structure engineering. In this study, the aluminum alloy three tube tower structure is taken as the prototype, and the middle joint of the tower was selected as the research object. Three different stainless steel-aluminum alloy composite joints (SACJs), denoted by TA, TB and TC, were designed. Finite element (FE) modeling analysis was used to compare and determine the TC joint as the best solution. Detail requirements of fasteners in the TC stainless steel-aluminum alloy composite joint (TC-SACJ) were designed and verified. In order to systematically and comprehensively study the mechanical properties of TC-SACJ under multi-directional loading conditions, the full-scale experiments and FE simulation models were all performed for mechanical response analysis. The failure modes, load-carrying capacities, and axial load versus displacement/stain testing curves of all full-scale specimens under tension/compression loading conditions were obtained. The results show that the maximum vertical displacement of aluminum alloy tube is 26.9mm, and the maximum lateral displacement of TC-SACJs is 1.0 mm. In general, the TC-SACJs are in an elastic state under the design load, which meet the design requirements and has a good safety reserve. This work can provide references for the design and engineering application of aluminum alloy tower structures.

PRC Maritime Operational Capability and the Task for the ROK Military (중국군의 해양작전능력과 한국군의 과제)

  • Kim, Min-Seok
    • Strategy21
    • /
    • s.33
    • /
    • pp.65-112
    • /
    • 2014
  • Recent trends show that the PRC has stepped aside its "army-centered approach" and placed greater emphasis on its Navy and Air Force for a wider range of operations, thereby reducing its ground force and harnessing its economic power and military technology into naval development. A quantitative growth of the PLA Navy itself is no surprise as this is not a recent phenomenon. Now is the time to pay closer attention to the level of PRC naval force's performance and the extent of its warfighting capacity in the maritime domain. It is also worth asking what China can do with its widening naval power foundation. In short, it is time to delve into several possible scenarios I which the PRC poses a real threat. With this in mind, in Section Two the paper seeks to observe the construction progress of PRC's naval power and its future prospects up to the year 2020, and categorize time frame according to its major force improvement trends. By analyzing qualitative improvements made over time, such as the scale of investment and the number of ships compared to increase in displacement (tonnage), this paper attempts to identify salient features in the construction of naval power. Chapter Three sets out performance evaluation on each type of PRC naval ships as well as capabilities of the Navy, Air Force, the Second Artillery (i.e., strategic missile forces) and satellites that could support maritime warfare. Finall, the concluding chapter estimates the PRC's maritime warfighting capability as anticipated in respective conflict scenarios, and considers its impact on the Korean Peninsula and proposes the directions ROK should steer in response. First of all, since the 1980s the PRC navy has undergone transitions as the focus of its military strategic outlook shifted from ground warfare to maritime warfare, and within 30 years of its effort to construct naval power while greatly reducing the size of its ground forces, the PRC has succeeded in building its naval power next to the U.S.'s in the world in terms of number, with acquisition of an aircraft carrier, Chinese-version of the Aegis, submarines and so on. The PRC also enjoys great potentials to qualitatively develop its forces such as indigenous aircraft carriers, next-generation strategic submarines, next-generation destroyers and so forth, which is possible because the PRC has accumulated its independent production capabilities in the process of its 30-year-long efforts. Secondly, one could argue that ROK still has its chances of coping with the PRC in naval power since, despite its continuous efforts, many estimate that the PRC naval force is roughly ten or more years behind that of superpowers such as the U.S., on areas including radar detection capability, EW capability, C4I and data-link systems, doctrines on force employment as well as tactics, and such gap cannot be easily overcome. The most probable scenarios involving the PRC in sea areas surrounding the Korean Peninsula are: first, upon the outbreak of war in the peninsula, the PRC may pursue military intervention through sea, thereby undermining efforts of the ROK-U.S. combined operations; second, ROK-PRC or PRC-Japan conflicts over maritime jurisdiction or ownership over the Senkaku/Diaoyu islands could inflict damage to ROK territorial sovereignty or economic gains. The PRC would likely attempt to resolve the conflict employing blitzkrieg tactics before U.S. forces arrive on the scene, while at the same time delaying and denying access of the incoming U.S. forces. If this proves unattainable, the PRC could take a course of action adopting "long-term attrition warfare," thus weakening its enemy's sustainability. All in all, thiss paper makes three proposals on how the ROK should respond. First, modern warfare as well as the emergent future warfare demonstrates that the center stage of battle is no longer the domestic territory, but rather further away into the sea and space. In this respect, the ROKN should take advantage of the distinct feature of battle space on the peninsula, which is surrounded by the seas, and obtain capabilities to intercept more than 50 percent of the enemy's ballistic missiles, including those of North Korea. In tandem with this capacity, employment of a large scale of UAV/F Carrier for Kill Chain operations should enhance effectiveness. This is because conditions are more favorable to defend from sea, on matters concerning accuracy rates against enemy targets, minimized threat of friendly damage, and cost effectiveness. Second, to maintain readiness for a North Korean crisis where timely deployment of US forces is not possible, the ROKN ought to obtain capabilities to hold the enemy attack at bay while deterring PRC naval intervention. It is also argued that ROKN should strengthen its power so as to protect national interests in the seas surrounding the peninsula without support from the USN, should ROK-PRC or ROK-Japan conflict arise concerning maritime jurisprudence. Third, the ROK should fortify infrastructures for independent construction of naval power and expand its R&D efforts, and for this purpose, the ROK should make the most of the advantages stemming from the ROK-U.S. alliance inducing active support from the United States. The rationale behind this argument is that while it is strategically effective to rely on alliance or jump on the bandwagon, the ultimate goal is always to acquire an independent response capability as much as possible.

Establishment of an Optimal Washing Condition of a High Temperature Steaming System for the Production of High Quality Pork (고품질 돈육 생산을 위한 고온증기세척수의 최적 조건)

  • Yang, H.S.;Jeong, J.Y.;Moon, S.H.;Park, G.B.;Joo, Seon-Tea
    • Journal of Animal Science and Technology
    • /
    • v.49 no.1
    • /
    • pp.121-128
    • /
    • 2007
  • The objective of this study was to determine the efficacy of different water temperatures and time of spray-washing on the removal of bacteria contamination from surface of pork carcass and to obtain better meat quality with high temperature stream between 60 to 90℃ for the time ranged from 10 to 60 sec. Results showed that total plate counts were significantly decreased with increasing steam temperature(P<0.05). Similar results were found with the spray time(P<0.05). The lightness(CIE L*) value was significantly increased in both loin and ham cuts over 80℃(P<0.05). Ultimate pH of muscle and water-holding capacity were decreased with increasing steam temperature(P<0.05). There was a significant difference in solubility of sarcoplasmic protein between 70℃ and 80℃ of the steam treatments with higher value at 70℃(P<0.05). Again, longer than 30 sec spray at 70℃ steam, the lightness value of pork was significantly increased(P<0.05), while pH and water-holding capacity of muscle were significantly decreased(P<0.05). Therefore, a desirable pork quality would be achieved with spray-steam washing at 70℃ for 20 sec on pork carcass.

Determination of cross section of composite breakwaters with multiple failure modes and system reliability analysis (다중 파괴모드에 의한 혼성제 케이슨의 단면 산정 및 제체에 대한 시스템 신뢰성 해석)

  • Lee, Cheol-Eung;Kim, Sang-Ug;Park, Dong-Heon
    • Journal of Korea Water Resources Association
    • /
    • v.51 no.9
    • /
    • pp.827-837
    • /
    • 2018
  • The stabilities of sliding and overturning of caisson and bearing capacity of mound against eccentric and inclined loads, which possibly happen to a composite caisson breakwaters, have been analyzed by using the technique of multiple failure modes. In deterministic approach, mathematical functions have been first derived from the ultimate limit state equations. Using those functions, the minimum cross section of caisson can straightforwardly be evaluated. By taking a look into some various deterministic analyses, it has been found that the conflict between failure modes can be occurred, such that the stability of bearing capacity of mound decreased as the stability of sliding increased. Therefore, the multiple failure modes for the composite caisson breakwaters should be taken into account simultaneously even in the process of deterministically evaluating the design cross section of caisson. Meanwhile, the reliability analyses on multiple failure modes have been implemented to the cross section determined by the sliding failure mode. It has been shown that the system failure probabilities of the composite breakwater are very behaved differently according to the variation of incident waves. The failure probabilities of system tend also to increase as the crest freeboards of caisson are heightening. The similar behaviors are taken place in cases that the water depths above mound are deepening. Finally, the results of the first-order modal are quite coincided with those of the second-order modal in all conditions of numerical tests performed in this paper. However, the second-order modal have had higher accuracy than the first-order modal. This is mainly due to that some correlations between failure modes can be properly incorporated in the second-order modal. Nevertheless, the first-order modal can also be easily used only when one of failure probabilities among multiple failure modes is extremely larger than others.

Analysis of Carcass Quality Grade Components and ChemicoPhysical and Sensory Traits of M. longissimus dorsi in Hanwoo (한우 도체 육질등급 요인 분석과 육질등급에 따른 이화학 및 관능 특성)

  • Lee, J.M.;Park, B.Y.;Cho, S.H.;Kim, J.H.;Yoo, Y.M.;Chae, H.S.;Choi, Y.I.
    • Journal of Animal Science and Technology
    • /
    • v.46 no.5
    • /
    • pp.833-840
    • /
    • 2004
  • The current study was conducted to analysis the effects of sex and live weight on carcass characteristics using total 773 Hanwoo, and to assess the effects of quality grade on chemico-physical and sensory characteristics in longissimus muscle. Results show that both steer and cow received superior quality grade to bull within the same weight c1ass(P < 0.05). Marbling score, texture, maturity, meat color and fat color were significantly( P< 0.01) affected by sex, whilst only marbling score and maturity were significantly affected by live weight. The ultimate quality grade showed significant relationships with marbling score(r = - $0.81^{**}) meat color (r= 0.21^{**}) fat color(r = 0.10^{**}) and with texture(r = 0.41^{**})$ but that had no such a relationship with maturity. WB-shear force and cooking loss were decreased when carcass grade was increased(P < 0.01), but water-holding capacity was identical between the quality grades. Objective meat color dimensions in lightness, redness and yellowness were increased for higher quality grade(P< 0.01). Meat flavor, juiciness and tenderness received higher scores for higher quality grade(P< 0.01). Intramuscular fat content had significantly relationships with WB-shear force(r = 0.$56^*), water-holding capacity(r = 0.18^{**}), juiciness(r = 0.46^{**}), tenderness(r= 0.49^{**})$, and flavor intensity(r = 0.$34^*$). In addition, a higher WB-shear force was related to a lower flavor, tenderness and juiciness scores.

Effects of Feeding Period of Organic Selenuim Supplementation on Meat Quality of Hanwoo Steers (유기 셀레늄 강화 버섯 폐배지 급여기간이 쇠고기육질에 미치는 영향)

  • Park Beom-Young;Kim Jin-Hyoung;Hwang In-Ho;Hah Kyung-Hee;Lee Seong-Hun;Cho Soo-Hyun;Kim Dong-Hun;Lee Jong-Moon;Kim Wan-Young
    • Food Science of Animal Resources
    • /
    • v.25 no.4
    • /
    • pp.430-435
    • /
    • 2005
  • Current study was conducted to investigate the effect of organic selenium supplementation originated from mushroom culture medium on meat quality of Hanwoo sleets. The result showed that organic selenium supplementation of 0.9 ppm (DM based ratio) for 2 (T1), 4 (T2) and 6 (T3) months had no effect on moisture content in longissimus muscle, with 63 to $66\%$ compared to non-supplemented control group Similarly, intramuscular fat content ranged from 11.7 to $16.4\%$ did not differ between the treatment groups (p>0.05). T3 group showed the highest protein content with $20.8\%$ while T2 group had the lowest content with $19.2\%$ The data indicated that organic selenium supplementation to the experimental concentration had indictable effect on proximate composition The treatments similarly had no influence on physical and biological characteristics of longissimus muscle, where cooking loss and shear force ranged from 20 to $21\%$ and from 3.6 to 4.4kg, respectively. On the other hand, muscle pH at 24 h postmortem showed 5.52, 5.57, 5.50, 5.50 for control, T1, T2 and T3, respectively, indicating that the longer feeding period resulted in the lower ultimate un A similar trend was observed from water-holding capacity (63.8, 64.4 and $64.2\%$ for T1, T2 and T3, respectively) which was significantly higher than con01 group of $59.5\%$ For sensory evaluation, juiciness did not differ between the treatment groups, but n and n (5.30 and 5.28, respectively) showed significantly tender mat Particularly, T2 group received significantly higher flavor score among the treatment groups including controls. The data indicated that organic selenium supplementation to the experimental concentration had no effect on beef quality, but the treatment effect on anti-oxidation function is remained for further studies.

Clinical effects of combination anorganic bovine-derived hydroxyapatite matrix(ABM)/cell binding peptide (P-15) in periodontal intrabony defects (치주 골내낭에서 anorganic bovine-derived hydroxyapatite matrix(ABM)/cell binding peptide(P-15)의 임상적효과)

  • Won, Mi-Sook;Paik, Jeong-Won;Kim, Chang-Sung;Cho, Kyoo-Sung;Chai, Jung-Kiu;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
    • /
    • v.32 no.3
    • /
    • pp.565-576
    • /
    • 2002
  • The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. To achieve periodontal regeneration, various kinds of methods have been investigated and developed, including guided tissue regeneration and bone graft. Bone graft can be catagorized into autografts, allografts, xenografts, bone substitutes. And materials of all types have different biological activity and the capacity for periodontal regeneration, but ideal graft material has not been developed that fits all the requirement of ideal bone graft material. Intensive research is underway to identity, purify, synthesize a variety biologic modulators that may enhance wound healing and regeneration of lost tissues in periodontal therapy. The present study evaluates the effects of ABM/P-15 on the periodontal regeneration in intrabony defects of human. We used thirty four 2-wall or 3-wall osseous defects in premolars and molars of chronic peridontitis patient that have more than 5mm pockets and more than 3mm in intrabony defect. 12 negative control group underwent flap procedure only, 11 positive control group received DFDBA graft with flap procedure, and 11 experimental group received ABM/P-15 graft with flap procedure. The changes of probing pocket depth, loss of attachment and bone probing depth following 6months after treatment revealed the following results: 1. The changes of probing pocket depth showed a statistically significant decrease between after scaling and 6months after treatment in negative control(2.0${\pm}$0.9mm), positive control(3.0${\pm}$0.9mm), and experimental group (3.4${\pm}$1.5mm) (P<0.01). Significantly more reduction was seen in experimental group compared to negative control group (P<0.05). 2. The changes of loss of attachment showed a statistically significant decrease between after scaling and 6months after treatment in positive control(2.0${\pm}$0.6mm), and experimental group (2.2${\pm}$l.0mm) except negative control group(0.1${\pm}$0.7mm) (P<0.01). Significantly more reduction was seen in both experimental and positive control group compared to negative control group(P<0.05). 3. The changes of bone probing depth showed a statistically significant decrease between after scaling and 6months after treatment in positive control(2.7${\pm}$l.0mm), and experimental group (3.4${\pm}$1.3mm) except negative control(0.l${\pm}$0.9mm) (9<0.01). Significantly more reduction was seen in both experimental and positive control group compared to negative control group (P<0.05). The results suggest that the use of ABM/P-15 in the treatment of periodontal intrabony defects can reduce loss of attachment and bone probing depth more than flap operation only. It suggests that ABM/P-15 may be an effective bone graft material for the regeneration of periodontal tissue in intrabony defects.

Clinical Long-term Assessment of Bioactive Glass Graft (Bioactive glass의 장기 임상적 평가)

  • Lee, Hang-Bin;Baek, Jeong-Won;Kim, Chang-Sung;Choi, Seong-Ho;Cho, Kyoo-Sung;Kim, Chong-Kwan;Chai, Choong-Kyoo
    • Journal of Periodontal and Implant Science
    • /
    • v.32 no.1
    • /
    • pp.187-198
    • /
    • 2002
  • The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. To achieve periodontal regeneration, various kinds of methods have been investigated and developed, including guided tissue regeneration and bone graft. Bone graft can be catagorized into autografts, allografts, xenografts, bone substitutes. And materials of all types have different biological activity and the capacity for periodontal regeneration, but ideal graft material has not been developed that fits all the requirement of ideal bone graft material. Recently, bioactive glass that has been utilized in plastic surgery is being investigated for application in dental practice. But, there has not been any long-term assessment of bioactive glass when used in periodontal intrabony defects. The present study evaluates the long-term effects of bioactive glass on the periodontal regeneration in intrabony defects of human and the effect of plaqu control on long term treatment results after dividing patients into those who underwent 3-month regular check-up and those who didn't under go regular check-up The clinical effect on 74sites from 17 infrabony pockets of 11 patients were analyzed 36months after treatment. 51 sites which underwent regular check up were classified as the Follow-up group(F/U group), and 23 sites which did not undergo regular check up were classified as Non Follow-up group(Non F/U group). After comparing the probing depth, attachment loss, bone probing depth before and 36months after treatment, the following results could be concluded. 1. The changes of probing pocket depth showed a statistically significant decrease between after baseline and 36 months after treatment in F/U group(1.79${\pm}$0.68mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(0.61${\pm}$0.54mm) (P<0.05). 2. The changes of loss of attachment showed a statistically significant decrease between after baseline and 36 months after treatment in F/U group(1.44${\pm}$0.74mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(1.18${\pm}$1.54) (P<0.05). 3. The changes of bone probing depth showed a statistically significant decrease between after baseline and 36 months after treatment in both F/U(1.35${\pm}$0.28) and Non F/U group(0.78${\pm}$0.55mm) (P<0.05). The results suggest that treatment of infrabony defects with bioactive glass resulted in significan reduction of attachment loss and bone probing depth 36months after the treatment. The use of bioactive glass in infrabony defects, combined with regular check-up and proper plaque control generally shows favorable clinical results. This measn that bioactive glass could be a useful bone substitute.

A Study of the Application of 'Digital Heritage ODA' - Focusing on the Myanmar cultural heritage management system - (디지털 문화유산 ODA 적용에 관한 시론적 연구 -미얀마 문화유산 관리시스템을 중심으로-)

  • Jeong, Seongmi
    • Korean Journal of Heritage: History & Science
    • /
    • v.53 no.4
    • /
    • pp.198-215
    • /
    • 2020
  • Official development assistance refers to assistance provided by governments and other public institutions in donor countries, aimed at promoting economic development and social welfare in developing countries. The purpose of this research is to examine the construction process of the "Myanmar Cultural Heritage Management System" that is underway as part of the ODA project to strengthen cultural and artistic capabilities and analyze the achievements and challenges of the Digital Cultural Heritage ODA. The digital cultural heritage management system is intended to achieve the permanent preservation and sustainable utilization of tangible and intangible cultural heritage materials. Cultural heritage can be stored in digital archives, newly approached using computer analysis technology, and information can be used in multiple dimensions. First, the Digital Cultural Heritage ODA was able to permanently preserve cultural heritage content that urgently needed digitalization by overcoming and documenting the "risk" associated with cultural heritage under threat of being extinguished, damaged, degraded, or distorted in Myanmar. Second, information on Myanmar's cultural heritage can be systematically managed and used in many ways through linkages between materials. Third, cultural maps can be implemented that are based on accurate geographical location information as to where cultural heritage is located or inherited. Various items of cultural heritage were collectively and intensively visualized to maximize utility and convenience for academic, policy, and practical purposes. Fourth, we were able to overcome the one-sided limitations of cultural ODA in relations between donor and recipient countries. Fifth, the capacity building program run by officials in charge of the beneficiary country, which could be the most important form of sustainable development in the cultural ODA, was operated together. Sixth, there is an implication that it is an ODA that can be relatively smooth and non-face-to-face in nature, without requiring the movement of manpower between countries during the current global pandemic. However, the following tasks remain to be solved through active discussion and deliberation in the future. First, the content of the data uploaded to the system should be verified. Second, to preserve digital cultural heritage, it must be protected from various threats. For example, it is necessary to train local experts to prepare for errors caused by computer viruses, stored data, or operating systems. Third, due to the nature of the rapidly changing environment of computer technology, measures should also be discussed to address the problems that tend to follow when new versions and programs are developed after the end of the ODA project, or when developers have not continued to manage their programs. Fourth, since the classification system criteria and decisions regarding whether the data will be disclosed or not are set according to Myanmar's political judgment, it is necessary to let the beneficiary country understand the ultimate purpose of the cultural ODA project.