• Title/Summary/Keyword: Failure area index

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The Effects of Reinforced Walking Exercise on Dyspnea-fatigue Symptoms, Daily Activities, Walking Ability, and Health related Quality of Life in Heart Failure Patients (강화된 걷기운동 중재가 심부전 환자의 호흡곤란과 피로증상, 일상생활 기능상태, 보행능력 및 건강 관련 삶의 질에 미치는 효과)

  • Jin, Hyekyung;Lee, Haejung
    • Korean Journal of Adult Nursing
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    • v.28 no.3
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    • pp.266-278
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    • 2016
  • Purpose: The purpose of this study was to identify the effects of reinforced walking exercise on dyspnea-fatigue symptoms, daily activities, walking ability and health related quality of life (HRQoL) in heart failure patients. Methods: This study used a randomized controlled trial design. The participants (experimental group=16, control group=25) were recruited from a university hospital in Kyeong-nam area. Data were collected from March to September, 2015. The reinforced walking exercise included goal setting and feedback (telephone and text message) provided for 12 weeks. Dyspnea-Fatigue Index, Korean Activity Scale/Index (KASI), six-minute walking distance (6MWD) and HRQoL were measured. Data were analyzed using descriptive statistics, t-test, Fisher's exact test, $x^2$ test, and Kolmogrove-Smirnov test. Results: Prior to the intervention there were no differences in the research variables between two groups. The exercise compliance in the experimental group was 100% (walking for 50 minutes per day, 5 times per week). The experimental group had improved dyspnea-fatigue symptoms (t=8.63, p<.001), daily activities (t=-4.92, p<.001), longer 6MWD (t=-5.66, p<.001), and increased HRQoL (t=-9.05, p<.001) compared to the control group. Conclusion: The reinforced walking exercise could be a cost-effective intervention in heart failure patient, which could enhance patients' outcomes, such as improving dyspnea-fatigue symptoms, daily activities, walking ability, and quality of life.

Soil Characteristics of soft clay in Nakdong-River Basin by considering Sample Disturbance (시료교란 정도를 고려한 낙동강 하구 유역 점토의 토질역학적 특성)

  • 이경은;정두회
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.111-118
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    • 2002
  • Recent study of soft clay of Nakdong-River basin has been taken correlation between soil properties by regression analysis without distribution whether the sample is disturbed or not, or treated as a whole area without proposing local correlation equation to Jang-U or Dae-Joe which has a specific locality. Accordingly, Those tendency cause the reliability of correlation between compression index and void ratio low and then design underestimate and uncertain eventually. In this study, Distributing the soft clay of Nakdong-River basin with failure strain of 6%, the suggestion by Skempton(1957), TakeNaka(1966)-the more sample is undisturbed, the more the ratio of E$\_$50/ and q$\_$u/, ${\alpha}$ = E$\_$50//(q$\_$u//2) = 1/$\varepsilon$$\_$50/ is high-is satisfied with the value of which ${\alpha}$ is 50 and It could be taken enough data in the condition of domestic. Besides other indices also make the distribution suitable. In conclusion, This study is supposed to propose the locally subdivided regression equation between compression index and void ratio considering the sample disturbance.

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Evaluation of cyclic fracture in perforated beams using micromechanical fatigue model

  • Erfani, Saeed;Akrami, Vahid
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.913-930
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    • 2016
  • It is common practice to use Reduced Web Beam Sections (RWBS) in steel moment resisting frames. Perforation of beam web in these members may cause stress and strain concentration around the opening area and facilitate ductile fracture under cyclic loading. This paper presents a numerical study on the cyclic fracture of these structural components. The considered connections are configured as T-shaped assemblies with beams of elongated circular perforations. The failure of specimens under Ultra Low Cycle Fatigue (ULCF) condition is simulated using Cyclic Void Growth Model (CVGM) which is a micromechanics based fracture model. In each model, CVGM fracture index is calculated based on the stress and strain time histories and then models with different opening configurations are compared based on the calculated fracture index. In addition to the global models, sub-models with refined mesh are used to evaluate fracture index around the beam to column weldment. Modeling techniques are validated using data from previous experiments. Results show that as the perforation size increases, opening corners experience greater fracture index. This is while as the opening size increases the maximum observed fracture index at the connection welds decreases. However, the initiation of fracture at connection welds occurs at lower drift angles compared to opening corners. Finally, a probabilistic framework is applied to CVGM in order to account for the uncertainties existing in the prediction of ductile fracture and results are discussed.

Probability Distribution of Geotechnical Properties of Songdo area in Incheon (인천 송도지역 지반정수의 확률분포 추정)

  • Kim, Dong-Hee;Kim, Min-Tae;Ko, Seong-Kwon;Park, Jung-Gyu;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1399-1406
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    • 2009
  • Probability distribution of geotechnical properties is very useful information and it is used for evaluating the geotechnical properties itself and calculating probability of failure. In this study, probability distribution of compression index, recompression index, and void ratio are evaluated, and analysis results show that all property distributions satisfy normal and log-normal distribution.

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A Study of Reliability Analysis and Application on Naval Combat System Using Field Critical Failure Data (야전 치명고장자료를 이용한 함정전투체계 신뢰성 분석 및 활용 방안)

  • Kim, Young-Jin;Oh, Hyun-Seung;Choi, Bong-Wan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.4
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    • pp.49-59
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    • 2016
  • Naval combat system developed in-country is progressing at an alarming rate since 2000. ROK navy will be achieved all vessels that have combat system in the near future. The importance of System Engineering and Integrated Logistics Support based on reliability analysis is increasing. However, reliability analysis that everyone trusted and recognized is not enough and applied practically for development of Defense Acquisition Program. In particular, Existing Reliability Analysis is focusing on reliability index (Mean Time Between Failure (MTBF) etc.) for policy decision of defense improvement project. Most of the weapon system acquisition process applying in the exponential distribution simply persist unreality due to memoryless property. Critical failures are more important than simple faults to ship's operator. There are no confirmed cases of reliability analysis involved with critical failure that naval ship scheduler and operator concerned sensitively. Therefore, this study is focusing on Mean Time To Critical Failure (MTTCF), reliability on specific time and Operational Readiness Float (ORF) requirements related to critical failure of Patrol Killer Guided missile (PKG) combat system that is beginning of naval combat system developed in-country. Methods of analysis is applied parametric and non-parametric statistical techniques. It is compared to the estimates and proposed applications. The result of study shows that parametric and non-parametric estimators should be applied differently depending on purpose of utilization based on test of normality. For the first time, this study is offering Reliability of ROK Naval combat system to stakeholders involved with defense improvement project. Decision makers of defense improvement project have to active support and effort in this area for improvement of System Engineering.

A Case of the 1st Metatarsal Bone Fracture in a Patient with Chronic Kidney Disease Treated by Acupuncture with Complex Korean Medical Treatment (침 치료 중심의 한의 복합 치료로 호전된 만성 신부전 환자의 제 1지 중족골 골절 치험 1례)

  • Jae-Hoon Son;Min-Jeong Kim
    • Korean Journal of Acupuncture
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    • v.41 no.3
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    • pp.110-117
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    • 2024
  • Objectives : The objective of this study is to report a case of a patient with a fracture of the 1st metatarsal bone, whose symptoms improved after receiving Complex Korean Medical treatment mainly focused on acupuncture. Methods : During admission treatment, the patient received 2 sessions of acupuncture treatment, 1 session of pharmacopuncture treatment, and electromoxibustion daily. To assess the patient's condition regarding the 1st metatarsal bone fracture, X-rays were performed on the affected area of the patient on a weekly basis, along with a daily follow up on the Numerical Rating Scale (NRS), degree of swelling (measured in cm via measuring tape), and the temperature of the affected area. The Foot Function Index (FFI) and Health Assessment Questionnaire (HAQ) were also used to add credibility in assessing the patient's current condition. Results : After 4 weeks of hospital admission treatment, the NRS of the pain in the affected area decreased from 4 to 1, with the night pain NRS of the affected area also being reduced from 8 to 0. There was a general improvement in the swelling and temperature of the affected area, as well as the FFI and HAQ of the patient. Conclusions : The study shows that complex Korean medical treatment can be effective in treating patients with bone fractures even without interventions involving traditional Korean herbal medicine.

A Study on the Safe Route through the Analysis of the Density of the Gill Netters in the West Sea (자망어선 밀도 분석을 통한 서해안 안전항로에 관한 연구)

  • Yoo, Sang-Lok;Jeong, Jong-Chul;Jeong, Jae-Yong;Yim, Jeong-Bin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.389-401
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    • 2016
  • This study attempted to present the monthly distribution of the inshore gill netters for the prevention of propeller failure caused by the damage of fishing gear by the merchant vessels in the West Sea. This study was conducted using the transmitting device of fishing location (V-Pass) data for 1 year in 2014. The grid intervals are $30minute{\times}30minute$ ($latitude{\times}longitude$) based on the section of the sea. A total of 56 sections were analyzed by constructing a grid. The results revealed that the section no. 194 with the highest density index showed no fishing gear damage accident. But the section no. 193 with a relatively lower density index showed more frequent fishing gear damage accident. It is because the section no. 193 is included in the main route of the merchant vessels. Based on this analysis, it is found that the fishing gears are not damaged in proportion to density index but risk of damage exists according to the main routes of merchant vessels. Therefore, for the safe navigation of the merchant vessels, notifying the waters of $34.5^{\circ}{\sim}35.5^{\circ}$ at latitude and $125.67^{\circ}{\sim}126^{\circ}$ at longitude, as a navigational warning area from May through September, will prevent marine accident, such as propeller failure and fishing gear damage. Accordingly, when the merchant vessels navigate in the section no. 193 and 203, the area of $34.5^{\circ}{\sim}35.5^{\circ}$ at latitude and $125.5^{\circ}{\sim}125.67^{\circ}$ at longitude is recommended for the safe navigation.

Future water supply risk analysis using a joint drought management index in Nakdong river basin (결합가뭄관리지수(JDMI)를 이용한 낙동강 유역의 미래 용수공급 위험도 분석)

  • Yu, Ji Soo;Choi, Si-Jung;Kwon, Hyun-Han;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.51 no.spc
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    • pp.1117-1126
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    • 2018
  • Water supply system aims to meet the user's demand by securing water resources in a stable way. However, water supply failure sometimes happens because inflow decreases during drought period. Droughts induced by the lack of precipitation do not always lead to water supply failures. Thus, it is necessary to consider features of actual water shortage event when we evaluate a water supply risk. In this study, we developed a new drought index for drought management, i.e., Joint Drought Management Index (JDMI), using two water supply system performance indices such as reliability and vulnerability. Future data that were estimated from GCMs according to RCP 4.5 and 8.5 scenarios were used to estimate future water supply risk. After dividing the future period into three parts, the risk of water supply failure in the Nakdong River basin was analyzed using the JDMI. As a result, the risk was higher with the RCP 4.5 than the RCP 8.5. In case of RCP 4.5, W18 (Namgangdam) was identified as the most vulnerable area, whereas in case of RCP 8.5, W23 (Hyeongsangang) and W33 (Nakdonggangnamhae) were identified as the most vulnerable area.

Carbonation Analysis of Bridge Structures in Urban Area Based on the Results of the Field Test (현장실험결과를 활용한 국내 도심지 교량구조물의 탄산화 해석)

  • Kim, Hun-Kyom;Kim, Sung-Bo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.4
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    • pp.111-118
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    • 2010
  • Reinforced steel corrosion due to concrete carbonation is one of main factors on the durability of RC structure. The carbonation velocity have an effect on carbon dioxide density, concrete quality and structural shape. Specially, these problems have increased in urban area. This study investigates the carbonation status of the bridges and quantifies the effect of carbonation based on various domestic field data. The failure probability of durability is evaluated on the basis of reliability concept. According to experimental results of the carbonation depth, the carbonation depth increased with structural age and carbonation velocity decreased with high strength of concrete. In most cases, the failure probability of durability by carbonation was more than 10%. Also, The results requires the minimum cover thickness of 70-80mm for target safety index(${\beta}$=1.3) proposed by Korean concrete specification.

Slope Stability and Development of Debris Flow Deposit in the Ulleung Basin, East Sea (동해 울릉분지의 사면안정성 및 쇄설류 퇴적체의 발달)

  • Lee, Sun-Jong;Lee, Jeong-Min;Yoo, Dong-Geun;Lee, Go-Eun;Park, Soo-Chul
    • Economic and Environmental Geology
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    • v.50 no.2
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    • pp.129-143
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    • 2017
  • The shallow sediments in the southwestern Ulleung Basin consist of mass flow deposits such as slide/slump and debris flow deposits (DFD), caused by slope failure. These sediments are proven to be important in studying geological disaster and stability of the seafloor. In this paper, we analysised the flow accumulation and slope failure susceptibility of the Ulleung Basin on the basis of multi-beam data, collected in this area. We also studied the distribution pattern and the seismic characteristics of the DFD in the uppermost layer of the Ulleung Basin on the basis of seismic data. The slope susceptibility was calculated as the frequency ratio of each factors including slope, aspect, curvature and stream power index (SPI), which causes the slope failure. These results indicate that the slope failure is frequently to occur in the southern and western continental slope of the Ulleung Basin. The sediment flow (mass flow) caused by the slope failure converges to the north and northwest of the Ulleung Basin. According to the seismic characteristics, the uppermost layer in study area can be divided into four sedimentary unit. These sedimentary units develop from the south and southwest to the north and northwest in association with slope susceptibility and flow accumulation.