• Title/Summary/Keyword: Strength1 Assessment

Search Result 489, Processing Time 0.026 seconds

Reliability Analysis of Ship′s Longitrdinal Strength for the Rational Ship Structural Design (선박구조설계 합리화를 위한 선체 종강도의 신뢰성 해석)

  • Oi-H. Kim;Byung-J. Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.32 no.1
    • /
    • pp.25-36
    • /
    • 1995
  • The application of the reliability analysis is investigated as a probabilistic approach to the assessment of ship's structural strength and to the establishment of design format for longitudinal strength. Reliability analyses are carried out for 34 ships of tankers and bulk carriers built in HHI for some failure modes such as tensile yielding, compressive buckling and ultimate strength of hull girder. The safety assessment of each ship, the calculation of sensitivity factors and the derivation of target reliability index are performed. As results. the difference of reliability indices among ships is great for all modes. To provide more uniform levels of safety the establishment of new strength criteria using partial safety factors is performed. The partial safety factors for the design format are obtained according to the AFOSM method and the reliability-conditioned(RC) method. Finally, a design format using partial safety factors has been proposed. We could find out that new strength criteria can produce consistent reliability indices which are close to the target value.

  • PDF

Assessment of Incipient Decay of Radiata Pine Wood Using Stress-Wave Technique in the Longitudinal Direction (수축방향(樹軸方向) 응력파(應力波) 방법(方法)에 의(依)한 라디에타소나무의 초기부후(初期腐朽) 평가(評價))

  • Kim, Gyu-Hyeok;Jee, Woo-Kuen;Ra, Jong-Bum
    • Journal of the Korean Wood Science and Technology
    • /
    • v.24 no.2
    • /
    • pp.1-6
    • /
    • 1996
  • This study was performed to investigate the feasibility of using sonic stress-wave technique in the longitudinal direction for the assessment of incipient decay of radiata pine wood. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested nondestructively using stress-wave technique in the longitudinal direction and destructively. Decay detection, quantitative assessment of decay, and the prediction of residual strength of decayed wood with less than five percent weight loss can be feasible using stress-wave parameters (wave velocity, wave impedance, stress-wave elasticity) measured by stress-wave technique in the longitudinal direction and their percent reduction due to decay.

  • PDF

Incorporating mesh-insensitive structural stress into the fatigue assessment procedure of common structural rules for bulk carriers

  • Kim, Seong-Min;Kim, Myung-Hyun
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.7 no.1
    • /
    • pp.10-24
    • /
    • 2015
  • This study introduces a fatigue assessment procedure using mesh-insensitive structural stress method based on the Common Structural Rules for Bulk Carriers by considering important factors, such as mean stress and thickness effects. The fatigue assessment result of mesh-insensitive structural stress method have been compared with CSR procedure based on equivalent notch stress at major hot spot points in the area near the ballast hold for a 180 K bulk carrier. The possibility of implementing mesh-insensitive structural stress method in the fatigue assessment procedure for ship structures is discussed.

Use of Neurologic Assessment Performance and Education Needs of Neurologic Ward Nurses (신경계 간호사의 신경학적 검진 수행정도와 교육요구도에 대한 조사연구)

  • Kim, Jeoung Hee;Choi, Eun Mee;Ko, Young Mi;Park, Hee Ra;Kim, Yoon Kyoung;Koo, Chong Mo;Park, Ju Yoon;Seong, Sun Suk;Kwon, Mi Hee;Yun, Yeoun Sook;Park, Yun Rye
    • Journal of Korean Clinical Nursing Research
    • /
    • v.22 no.1
    • /
    • pp.46-55
    • /
    • 2016
  • Purpose: The purpose of this study was to describe performance and education needs related to neurologic assessment by neurologic ward nurses. Methods: The study was conducted with a cross-sectional descriptive design. Participants, 297 neurologic ward nurses working in ten major hospitals in Seoul and Gyeonggi were surveyed from September 7 to October 1, 2015. Results: The mean score for performance of neurologic assessments was 3.04 points. Performances performed with high quality were orientation exam, mental status documentation, and muscle strength of extremities in that order. Performances performed with low quality were assessment of accessory nerves, hypoglossal nerves, and cerebellum function in that order. There were significant differences according to whether there was ward education programs on neurologic assessment and teaching experiences within a year. These variables significantly affected the quality of neurologic assessment performance. The need for neurologic assessment training was 3.14 points. Conclusion: Amount of performance and demand for education on neurologic assessment, which are required in the clinical setting, were significantly high. To perform neurologic assessments with high quality, development of education program for neurologic assessment and continuous education courses are required at either the department or neurological nursing organization level.

Structural Safety Assessment of Independent Spherical LNG Tank(1st Report) - Fatigue Strength Analysis Based on the S-N Approach - (독립구형 LNG 탱크의 구조안전성 평가(제1보) - 피로균열 발생수명 예측 -)

  • In-Sik Nho;Yong-Yun Nam;Ho-Sup Lee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.30 no.2
    • /
    • pp.132-140
    • /
    • 1993
  • The design of LNG ship needs very high level structural design/analysis technology compared with conventional ship types because it requires perfect security against the extremly dangerous and cryogenic cargo. Hence, present paper describes the general procedure of the structural safety assessment for independent tank type LNG ship, which contains following items. 1) Long term prediction of the wave induced stresses including ship motion analysis, structural analysis of hull and tank and stochastic analysis process of ocean waves. 2) Fatigue strength analysis of a tank structure based on the S-N approach. 3) Structural safety assessment against the fatigue crack propagation based on the LBF(Leak Before Failure) concept. The first report focuced on the item (1) (2) and example calculation was performed on a prototype LNG ship. The remained part will be covered by the second report.

  • PDF

Technical and economical assessment of applying silica nanoparticles for construction of concrete structures

  • Rad, Sajad Shariati
    • Computers and Concrete
    • /
    • v.22 no.1
    • /
    • pp.117-122
    • /
    • 2018
  • The use of nanotechnology materials and applications in the construction industry should be considered for enhancing material properties. However, in this paper, the technical and economical assessment of applying silica nanoparticles for construction of concrete structure is studied. In order to obtain the equivalent material properties of the structure, the Mori-Tanaka model is used considering agglomeration of nanoparticles. The effect of using these nanoparticles on mechanical properties of concrete, such as the modulus of elasticity, compressive strength, as well as its indirect effect on armature percentage is investigated. Finally, the price of silica nanoparticles and its effect on the price increase of concrete structure is investigated. The results show that increasing the volume percent of silica nanoparticles up to 10% improves elastic modulus 111% and reduces amateur percentage up to 72%.

Assessment on Design Applicability of Analysis of the Undrained Shear Strength in Korea Coastal Marine Clay (국내 해성점토의 비배수 전단강도 분석을 통한 설계 적용성 평가)

  • Kim, Myeong Hwan;Song, Chang Seob
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.58 no.1
    • /
    • pp.61-71
    • /
    • 2016
  • This study performed the physical and mechanical experiment on the samples of costal marine clays individually collected in western and southern regions to identify the characteristics of western and southern costal marine clay. Based on the experiment result, the characteristics of costal marine clay is identified undrained shear strength. Based on the experiment result on the physical and mechanical characteristics of costal marine clays, the regression is presented that can analyze the mechanical characteristics of undrained shear strength in costal marine clay of Korea, region of Korea and western-southern region. The correlation of uniaxial compressive strength and undrained shear strength was suitable for use of western-southern region correlation equation. The test result of Jeonnam Yeosu area compares with prediction results of previous researchers formula and western-southern region formula. Prediction results appear highest reliability on the 0.827 of coefficient of determination in the prediction results of the western-southern region formula.

Tongue Strength, Range of Motion, and Speech Intelligibility in Dysarthric Speakers (마비말장애 환자의 혀의 강도.운동범위와 말명료도에 관한 연구)

  • Lee, Kyung-Ha;Sim, Hyun-Sub;Kim, Hyang-Hee
    • Speech Sciences
    • /
    • v.12 no.2
    • /
    • pp.89-99
    • /
    • 2005
  • The purpose of the present study were (1) to assess differences in tongue performances and speech intelligibility between normal and dysarthric speakers; and (2) to analyze the possible interrelationships between tongue strength, range of motion, and speech intelligibility in dysarthric patients. In order to measure maximum strength of anterior and lateral tongue strength, a force transducer has been designed. And a ruler was used for guaging range of motion. 'Word intelligibility test' was administered to each group. The results were analyzed by a quantitative statistical method(t test, Pearson product- moment correlation, and one-way ANOVA). The results were as follows; (1) dysarthric speakers showed significantly poorer performance than the normal in the tongue strength, range of motion, and speech intelligibility tasks; (2) the correlation between speech intelligibility and instrumental tongue performance was high in the dysarthric group; and (3) instrumental assessment was coincide with perceptual judgement of dysarthric tongue performance. The present investigation demonstrated that tongue weakness is causally related to articulation deficits in dysarthric. The clinical use of the force transducer would help a speech pathologist to quantify the degree of tongue weakness.

  • PDF

Comparison of machine learning algorithms to evaluate strength of concrete with marble powder

  • Sharma, Nitisha;Upadhya, Ankita;Thakur, Mohindra S.;Sihag, Parveen
    • Advances in materials Research
    • /
    • v.11 no.1
    • /
    • pp.75-90
    • /
    • 2022
  • In this paper, functionality of soft computing algorithms such as Group method of data handling (GMDH), Random forest (RF), Random tree (RT), Linear regression (LR), M5P, and artificial neural network (ANN) have been looked out to predict the compressive strength of concrete mixed with marble powder. Assessment of result suggests that, the overall performance of ANN based model gives preferable results over the different applied algorithms for the estimate of compressive strength of concrete. The results of coefficient of correlation were maximum in ANN model (0.9139) accompanied through RT with coefficient of correlation (CC) value 0.8241 and minimum root mean square error (RMSE) value of ANN (4.5611) followed by RT with RMSE (5.4246). Similarly, other evaluating parameters like, Willmott's index and Nash-sutcliffe coefficient value of ANN was 0.9458 and 0.7502 followed by RT model (0.8763 and 0.6628). The end result showed that, for both subsets i.e., training and testing subset, ANN has the potential to estimate the compressive strength of concrete. Also, the results of sensitivity suggest that the water-cement ratio has a massive impact in estimating the compressive strength of concrete with marble powder with ANN based model in evaluation with the different parameters for this data set.

Assessment and Comparison of Isokinetic Strength of Hip, Knee and Ankle Joints in Young Adults

  • Kim, Yong Hwan;Jee, Hae Mi
    • Journal of International Academy of Physical Therapy Research
    • /
    • v.9 no.1
    • /
    • pp.1426-1434
    • /
    • 2018
  • This study was conducted to observe the isokinetic strength (IS) of the hip, ankle, and knee joints in young age groups. Thirty eight men and thirty one women with mean age of $30.4{\pm}3.5$ and $32.8{\pm}4.4years$, respectively, were enrolled in this study. Measurements of hip flexion, extension, abduction, and adduction at $30^{\circ}/sec$, Knee flexion and extension at $60^{\circ}/sec$, ankle inversion, eversion, plantarflexion, and dorsiflexion $30^{\circ}/sec$ were conducted. Absolute IS (Nm), relative IS (Nm/kg), strength ratios, correlations between movements were observed. Significant differences in absolute and relative strength were observed between groups in all movement except in the relative ankle strength. Relative isokinetic strength ratios of hip flexion/extension were .45 and .55, knee flexion/extension were .84 and .89, ankle dorsi/plantarflexion were .30 and .29, and ankle eversion/inversion were .86 and .84 for men and women, respectively. In the hip extension, men had about three times the body weight, and women had about 2.5 times the strength. The abduction muscle had about 1.5 times the body weight of both men and women. Height and body weight showed the significantly strong correlating relationship with hip (r, .76-.86) and knee (r, .67-.84) strength. However, ankle strength showed the comparatively correlating relationship, especially in women (r, .03 - .36). Similar age and physique characteristics of female and male groups could provide useful isokinetic strength reference values for developing the exercise program for healthy and rehabilitation groups.