• 제목/요약/키워드: ultimate term

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Influence of the deteriorated anti-seismic devices on seismic performance and device behavior of continuous girder bridges

  • Shangtao Hu;Renkang Hu;Menggang Yang;Dongliang Meng
    • Earthquakes and Structures
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    • 제24권5호
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    • pp.333-343
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    • 2023
  • Various seismic isolation and reduction devices have been applied to suppress the longitudinal vibration of continuous girder bridges. As representative devices, lead rubber bearing (LRB) and fluid viscous damper (FVD) might suffer from deterioration during the long-term service. This study aims to evaluate the impact of device deterioration on the seismic responses of continuous girder bridges and investigate the seismic behavior of deteriorated LRBs and FVDs. Seismic performance of a simplified bridge model was investigated, and the influence of device deterioration was evaluated by the coefficient of variation method. The contribution of LRB and FVD was assessed by the Sobol global sensitivity analysis method. Finally, the seismic behaviors of deteriorated LRBs and FVDs were discussed. The result shows that (i) the girder-pier relative displacement is the most sensitive to the changes in the deterioration level, (ii) the deterioration of FVD has a greater effect on the structural responses than that of LRB, (iii) FVD plays a major role in energy dissipation with a low degradation level while LRB is more essential in dissipating energy when suffering from high degradation level, (iv) the deteriorated devices are more likely to reach the ultimate state and thus be damaged.

Development of automatic system for evaluating the stress redistribution in structural members of a steel cable-stayed bridge due to cable stress relaxation

  • Hong, Tien-Thang;Kim, Jung J.;Thai, Duc-Kien;Kim, Seung-Eock
    • Steel and Composite Structures
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    • 제44권6호
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    • pp.753-768
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    • 2022
  • In this study, a graphical automatic system is developed in order to investigate the stress redistribution of structural members in a steel cable-stayed bridge. The generalized Maxwell model is selected for stress relaxation estimation, and it is carefully verified and applied to all the cable members of a steel cable-stayed bridge to investigate its stress relaxation. A set of stress relaxation parameters in all cables is determined using the fmincon optimization function. The stress redistribution of the steel cable-stayed bridge is then analyzed using ABAQUS. To shorten the investigation time, all the aforementioned phases are built up to be an automatic system. The automatic system is then employed to investigate the effect of cable cross-section areas and girder spans on stress redistribution. The findings from these studies show that the initial tension in the cables of a steel cable-stayed bridge should be kept to less than 55% of the cable's ultimate strength to reduce the effect of cable stress relaxation. The cable space in a steel cable-stayed bridge should be limited to 15,000 mm to minimize the effect of cable stress relaxation. In comparison to other structural members of a steel cable-stayed bridge, the girders experience a significant stress redistribution.

조현병 환자를 위한 정신사회적 중재 (Psychosocial Intervention for Patients with Schizophrenia)

  • 김성완
    • 신경정신의학
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    • 제57권3호
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    • pp.235-243
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    • 2018
  • Treatment of schizophrenia has as its ultimate goals, the functional recovery of the patients and improvement of their quality of life. While antipsychotic medication is the fundamental method for treating schizophrenia, it has certain limitations in terms of treating the illness beyond its positive symptoms. Therefore, psychosocial intervention should be used in tandem with pharmacological methods in treating schizophrenia. The efficacy of several modes of psychosocial intervention for improving outcomes in schizophrenia is well attested. Approximately 10 modes of psychosocial intervention have been recommended based on existing evidence, including family intervention, cognitive behavioral therapy, supported employment, early intervention services, lifestyle intervention for physical health enhancement, treatment of comorbid substance abuse, assertive community treatment, cognitive remediation, social skills training, and peer support. Ideally, these interventions are offered to patients in combination with one another. Over the last decade, increased emphasis has been placed on early detection and intervention, with particular focus on long-term recovery. Early intervention with comprehensive psychosocial interventions should be enacted promptly from the initial detection of schizophrenia.

오수유와 마황이 저열량식이요법을 병행한 비만여성환자의 체구성성분 및 휴식대사량에 미치는 영향 (The Effects of Evodia Rutaecarpa and Ephedra Sinica on the Resting Metabolic Rate and Body Composition of Obese Women on a Low-Calorie Diet: A Double-blinded Randomized Controlled Clinical Trial)

  • 박정미;김호준;김진아;김수진;고병표
    • 대한한의학회지
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    • 제26권3호
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    • pp.249-262
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    • 2005
  • Backgrounds : As obesity prevails as an epidemic. diet programs including low-calorie diets are developed continuously. It is generally believed that a low-calorie diet is commonly followed by resting metabolic rate decrease and ultimate weight regain. Ephedra and Evodia are known to have sympathomimetic and anti-obesity effect. Objectives : This study was a prospective, double-blinded, randomized md placebo-controlled clinical trial to evaluate the effects of Ephedra sinica and Evodia rutaecarpa on resting metabolic rate (RMR), weight, body composition, and short-term safety in obese women on low-calorie diet. Methods : 125 otherwise healthy obese women (body mass Index ${\geq}\;25kg/m^2$) were recruited and randomly assigned to three groups: Ephedra group (n=41), Evodia group (n =45), and placebo group (n=39). Subjects were administered Ephedra extract in capsules (pseudo-ephedrine 31.52mg) or Evodia extract in capsules (evodiamine 6.75mg, rutaecarpine 0.66mg) or placebo capsules as well as participating in a low-calorie diet for 8 weeks, Resting metabolic rate and body composition were measured at baseline,4 and 8 weeks. Basic serum exams were performed to evaluate the short-term safety of the herbs and changes of lipid variables. Results : All three groups showed significant BMI decreases probably due to low-calorie diet. Among them, the Ephedra group manifested most prominent BMI-reducing effect and towered total cholesterol and triglycerides significantly. The RMR was not changed during the 8-week diet in all groups. No significant difference among the groups was found in RMR, either. Stbject with higher RMR than the mean at the baseline showed a tendency to keep their RMR more stable during the diet program. Conclusions : Ephedra with a low-calorie diet was effective in reducing BMI. RMR change was not compensated by herbal medicines. RMR change seemed to be affected rather by constitution and body composition than medicine. Ephedra and Evodia were proven to be safe for sort-term use in herbal form. Especially, Ephedra was effective in lowering total cholesterol and triglycerides during the 8 weeks.

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Early and Long-term Outcomes of Pneumonectomy for Treating Sequelae of Pulmonary Tuberculosis

  • Byun, Chun-Sung;Chung, Kyung-Young;Narm, Kyoung-Sik;Lee, Jin-Gu;Hong, Dae-Jin;Lee, Chang-Young
    • Journal of Chest Surgery
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    • 제45권2호
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    • pp.110-115
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    • 2012
  • Background: Pneumonectomy remains the ultimate curative treatment modality for destroyed lung caused by tuberculosis despite multiple risks involved in the procedure. We retrospectively evaluated patients who underwent pneumonectomy for treatment of sequelae of pulmonary tuberculosis to determine the risk factors of early and long-term outcomes. Materials and Methods: Between January 1980 and December 2008, pneumonectomy or pleuropneumonectomy was performed in 73 consecutive patients with destroyed lung caused by tuberculosis. There were 48 patients with empyema (12 with bronchopleural fistula [BPF]), 11 with aspergilloma and 7 with multidrug resistant tuberculosis. Results: There were 5 operative mortalities (6.8%). One patient had intraoperative uncontrolled arrhythmia, one had a postoperative cardiac arrest, and three had postoperative respiratory failure. A total of 29 patients (39.7%) suffered from postoperative complications. Twelve patients (16.7%) were found to have postpneumonectomy empyema (PPE), 4 patients had wound infections (5.6%), and 7 patients required re-exploration due to postoperative bleeding (9.7%). The prevalence of PPE increased in patients with preoperative empyema (p=0.019). There were five patients with postoperative BPF, four of which occurred in right-side operation. The only risk factor for BPF was the right-side operation (p=0.023). The 5- and 10-year survival rates were 88.9% and 76.2%, respectively. The risk factors for late deaths were old age (${\geq}50$ years, p=0.02) and low predicted postoperative forced expiratory volume in one second (FEV1) (< 1.2 L, p=0.02). Conclusion: Although PPE increases in patients with preoperative empyema and postoperative BPF increases in right-side operation, the mortality rates and long-term survival rates were found to be satisfactory. However, the follow-up care for patients with low predicted postoperative FEV1 should continue for prevention and early detection of pulmonary complication related to impaired pulmonary function.

반복 일사하중에 대한 철근콘크리트 지붕슬래브의 구조적 거동 (Structural Behavior of RC Roof Slab under Cyclic Temperature Load)

  • 서수연;윤승조;조용만;최기봉
    • 한국구조물진단유지관리공학회 논문집
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    • 제14권2호
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    • pp.67-74
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    • 2010
  • 철근콘크리트 지붕 슬래브에 작용하는 온도변화는 여름에는 부재를 팽창시키고 겨울에는 수축시키기 때문에 콘크리트의 응력변화를 야기시키며 이와 같은 거동은 년단위로 반복되어 사용성과 극한상태 모두에 대해서 부재의 구조성능에 영향을 미친다. 본 논문에서는 최근 20년 동안 한국의 기상변화를 분석하여 온도변화의 패턴을 계산하였으며 또한 이와 같이 장기적으로 반복되는 온도변화에 대한 영향을 실험적으로 연구하였다. 6개의 동일한 형태를 가진 철근콘크리트 슬래브를 제작하고 가력주기와 손상유무를 주 변수로 실험을 실시하였다. 실험으로부터, 1년, 10년 20년 동안의 가력기간 변화에 따른 슬래브의 강성변화에서, 여름의 경우에는 10년에서 1년 일 때의 강성과 비교하여 약 30% 정도 감소되고 겨울의 경우에는 30년 이후부터 약 31%(1년과 비교) 저하되는 것으로 나타났다. 또한 이들 손상된 RC슬래브에 대한 파괴실험을 통하여 슬래브 부재의 보유성능을 평가한 결과, 외기에 노출된 기간의 변화에 따른 슬래브 부재의 초기강성 및 최대내력의 변화는 크지 않은 것으로 나타났다. 단, 20년 이상의 반복온도하중을 받은 경우에는 항복내력이 낮아지는 경향을 보이는 것으로 나타났다.

캐나다 Long-Term Athlete Development(LTAD) 고찰을 통한 국내 스포츠시스템의 통합모델과 운영방안 (Integration of the Korea Sport System: Feasibility of the Canadian LTAD framework)

  • 이은영;임희준;원도연;전용관;정재용
    • 한국체육학회지인문사회과학편
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    • 제55권5호
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    • pp.619-633
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    • 2016
  • 지난 2015년 3월 27일 공포된 체육단체의 통합은 대한민국이 "스포츠강국"에서 "스포츠선진국"으로 발돋움 할 수 있는 계기를 마련한 국내 체육계의 노력의 결실이며, 스포츠계 새로운 패러다임의 도입이다. 이에 본 논문은 체육단체의 성공적인 통합을 위한 스포츠시스템과 프로그램 측면 토대의 마련을 위해, 지난 2012년부터 캐나다의 체육단체 통합과 스포츠시스템의 운영에 발판이 된 Long-Term Athlete Development(LTAD) 프레임워크를 비판적으로 살펴 본 후, 국내 활용도에 대해서 논의해보고자 한다. 또한, 이를 바탕으로 국내에 적합한 통합모델의 제시와 운영전략을 제시하였다. 본 논문에서 제시한 "한국형 스포츠시스템 통합모델"은 우리나라 전 국민을 대상으로 연령·발육발달단계·스포츠 입문 시기 별 스포츠 참여의 틀을 제공한다. 이는 지난 10년 간 체육계의 쟁점이었던 학교체육·엘리트체육·생활체육의 연계는 물론 엘리트선수의 발굴과 육성, 그리고 평생체육으로의 연계까지 가능하게 할 것으로 생각된다. "한국형 스포츠시스템 통합모델"은 앞으로 실제에의 적용, 평가, 그리고 수정의 과정을 거쳐 지속적으로 진화해 나아가야 할 것이다.

강절형 목질 문형라멘프레임의 수평내력성능 평가 (Evaluation of The Lateral Strength Performance of Rigid Wooden Portal Frame)

  • 이인환;송요진;홍순일
    • Journal of the Korean Wood Science and Technology
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    • 제45권5호
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    • pp.535-543
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    • 2017
  • 목구조물 기둥-보 접합물로는 슬릿 가공된 부재에 강판을 삽입한 형상이 통용되고 있다. 본 연구에서는 접합부가 접착된 강절형 문형라멘프레임 및 강판 대용인 목질접합물을 제작하여 절반은 기둥부재에 일체화하고 나머지 절반은 보부재와 핀으로 접합한 반강절형 문형라멘프레임을 제작하였다. 목질 문형라멘프레임들은 강판삽입형 접합부 문형라멘프레임과 수평내력성능을 비교 분석하였다. 수평내력성능은 완전탄소성모델 분석과 구간별 강성변화율 및 단기허용전단내력으로 평가하였다. 실험결과, 강절형 문형라멘프레임의 최대내력이 강판삽입형 접합부 문형라멘프레임 보다 낮게 측정되어 항복 내력은 0.58, 종국내력은 0.48로 산출되었으나, 초기강성과 소성률은 각각 1.35, 1.1 향상된 값이 측정되었다. 반강절형 문형라멘프레임의 완전탄소성모델 분석 결과 최대내력은 강절형 문형라멘프레임보다 낮았으나 파괴 후 인성이 우수하여 종국내력은 1.05~1.07 높은 값이 산출되었다. 강판삽입형 문형라멘프레임은 반복 시험이 진행됨에 따라 강성이 급격히 감소한 반면 접합부가 목질로된 문형라멘프레임들의 강성은 서서히 감소되었다.

Effect of Transportation at High Ambient Temperatures on Physiological Responses, Carcass and Meat Quality Characteristics in Two Age Groups of Omani Sheep

  • Kadim, I.T.;Mahgoub, O.;AlKindi, A.Y.;Al-Marzooqi, W.;Al-Saqri, N.M.;Almaney, M.;Mahmoud, I.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권3호
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    • pp.424-431
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    • 2007
  • The aim of this study was to determine the effects of short road transportation in an open truck during hot season on live weight shrink, physiological responses, and carcass and meat quality of Omani sheep at 6 and 12 months of age. Thirty-six male sheep, 18 of each age group, were used. Age groups were assigned randomly to transported and not-transported groups. The transported group was transported to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 100 km. The average temperature during transportation was $37^{\circ}C$. The not-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 48 h prior to slaughter. Blood samples were collected from sheep before loading and prior to slaughter via jugular venipuncture to assess their physiological response to transport in relation to hormonal levels. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length and colour L*, a*, b* were measured on samples from longissimus dorsi, biceps femoris and semitendinosus muscles collected at 24 h postmortem at $1-3^{\circ}C$. Live weight shrinkage losses were 1.09 and 1.52 kg for 6 and 12 month transported sheep, respectively. The transported sheep had significantly (p<0.05) higher cortisol, adrenaline, noradrenaline, and dopamine concentration levels prior to slaughter at both ages than the not-transported sheep. Transportation significantly influenced meat quality characteristics of three muscles. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than not-transported sheep. Age had a significant effect on meat quality characteristics of Omani sheep. These results indicated that short-term pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep.

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

  • 이항빈;백정원;김창성;최성호;조규성;김종관;채중규
    • Journal of Periodontal and Implant Science
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    • 제32권1호
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    • pp.187-198
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    • 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.