• Title/Summary/Keyword: 설계변수

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Impact of a Palliative Care Education Program on Korean Hospice Volunteers: Motivation, Death Anxiety, and Communication with the Dying

  • Woo, Hee Young;Yeun, Young Ran
    • Journal of Hospice and Palliative Care
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    • v.21 no.2
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    • pp.58-64
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    • 2018
  • Purpose: This study was conducted to evaluate the impact of a two-week palliative care education program on Korean Hospice volunteers. Methods: A total of 71 volunteers were assigned to two groups: Group A (intervention, n=34) and Group B (usual care, n=37). Group A received six sessions of palliative care education for two weeks. The level of volunteers' motivation, death anxiety, and communication with the dying were measured at baseline and after the program ended. Results: The palliative care education program had positive influence on the volunteers' motivation (t=2.341, P=0.022), death anxiety (t=-2.166, P=0.034), and communication with the dying (t=-2.808, P=0.006). Conclusion: The findings of this study suggest that a palliative care education program may be an effective way to boost hospice volunteers' motivation, ease their death anxiety and improve their communication with the dying.

Study on the Natural Frequency of Wind Turbine Tower Based on Soil Pile interaction to Evaluate Resonant Avoidance Frequency (지반조건 상호작용을 고려한 풍력발전타워의 공진회피 진동수 산정을 위한 고유진동수 해석 연구)

  • Kim, Pyoung-Hwa;Kang, Sung-Yong;Lee, Yun-Woo;Kang, Young-jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.734-742
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    • 2016
  • Global warming and the depletion of fossil fuels have been caused by decades of reckless development. Wind energy is one form of renewable energy and is considered a future energy source. The wind tower is designed with a fundamental frequency in the soft-stiff design between the 1P and 3P range to avoid resonance. Usually, to perform natural frequency analysis of a wind tower, the boundary condition is set to the Fixed-End, and soil-pile interaction is not considered. In this study, consideration of the effect of soil-pile interaction on the wind tower was included and the difference in the natural frequency was studied. The fixed boundary condition was not affected by the soil condition and depth of the pile and the coupled spring boundary condition was unaffected by the depth of pile but affected by the depth of the pile, and the Winkler spring boundary condition is affected by both the soil condition and the depth of the pile. Therefore, the coupled spring boundary condition should be used in shallow depth soil conditions because the soil condition does not take the shallow depth soil into consideration.

Characteristics and Dynamic Modeling of MR Damper for Semi-active Vibration Control (준능동 진동 제어를 위한 MR 감쇠기의 동적 모델링을 통한 특성분석)

  • Heo, Gwang-Hee;Jeon, Seung-Gon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.61-69
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    • 2013
  • This research is aimed to evaluate characteristics and dynamic modeling of MR damper for semi-active vibration control. A MR damper of semi-active type was designed and made for the purpose of controlling the vibration of a real-size model structure. Usually a semi-active control system equipped with a MR damper requires a dynamic model which expresses numerical data about the damping capacity and dynamic characteristics generated by a MR damper. To fulfil the requirement, a Power model and a Bingham model were particularly employed among many dynamic models of MR damper. Those models being contrasted with other ones, a dynamic test was carried out on the developed MR damper. In the test, excitation frequencies were conditioned to be 0.15 Hz, 1.0 Hz, and 2.0 Hz, and three different currents were adopted for each frequency. From these test results, it was found that displacement affected control capacity of the MR damper. The test results led to the identification of model variables for each dynamic model, on the basis of which a force-speed relation curve and expected damping force were derived and contrasted to those of the developed MR damper. Therefore, it was proven that the MR damper designed and made in this research was effective as a semi-active controller, and also that displacement of 2mm at minimum was found to be secured for vibration control, through the test using various displacements.

Experimental Study on Strength of Austentic Stainless Steel (STS 304L) Fillet-Welded Connection with Weld Metal Fracture According to Welding Direction (용접방향에 따른 오스트나이트계 스테인리스강(STS304L) 용착금속파단 용접접합부의 내력에 관한 실험적 연구)

  • Kim, Tae Soo;Lee, Hoochang;Hwang, Bokyung;Cho, Taejun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.81-89
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    • 2018
  • Austenitic stainless steels have excellent corrosion resistance, durability and fire resistance. Especially, since STS304L among austenitic types is a low-carbon variation of STS304 and has excellent intergranular corrosion resistance, it can often be used under the welded condition without heat treatment after field welding. This paper investigated ultimate behaviors such as ultimate strength and weld metal fracture mechanism of STS304L fillet-welded connections with TIG(tungsten inert gas) welding through test results. Main variables of specimens are weld length and welding direction against loading. Fracture of specimens are classified into three modes(tensile fracture, shear fracture and block shear fracture). Ultimate strengths were compared according to the welding direction and weld length and TFW series with transverse fillet weld had the highest strength compared with other types(LFW series with longitudinal fillet weld and FW series with all round weld). It is known that current design specifications such as KBC 2016 and AISC2010 underestimated the strength of TFW and LFW specimens and provided unconservative estimates for FW specimens. Finally, strength equations were proposed considering material properties of STS 304L material.

Sensitivity Analysis for Unit Module Development of Hybrid tube Structural System (복합 튜브 구조시스템의 단위 모듈 개발에 대한 민감도 해석)

  • Lee, Yeon-Jong;Park, Sung-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.167-175
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    • 2018
  • This research deals, The characteristics of mechanics and behavior of the tube structural systems, It has been investigated and considered conventional theory and case models, It has shown the suitability, The best location, And optimal shape of the unit module system, Considered variables materials of stiffness increase and decrease in hybrid tube structural systems this study carried out adapting analysis of statistical concepts. In a concrete way, This study exams the effect of reducing horizontal displacement and the shear lag phenomenon, Also, The purpose of this study is to utilize the basic data on the design and study of future high-rise hybrid structural system using this research. As a result, The framed- tube structural system does not effectively cope with horizontal behavior of high-rise buildings, The results of using varying material tested resistance factors and lateral loads in hybrid tube structural system, When each material is compared Bracing material is identified as a key factor in lateral behavior. In a ratio of material quantity framed-tube structural system, The level of sensitivity affecting the horizontal displacement is greater then the beam's column, In case of braced tube structural system, Braced appeared to be most sensitive in comparison of material quantity ratio in columns and beams.

Effects of Transverse Reinforcement on Headed Bars with Large Diameter at Cut-off Points (컷오프 구간에 정착된 대구경 확대머리철근에 대한 횡보강근의 효과)

  • Jung, Hyung-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.5
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    • pp.82-90
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    • 2018
  • The nuclear structures are composed of large diameter bars over No.36. If the hooked bars are used for anchorage of large diameter bars, too long length of the tail extension of the hook plus bend create congestion and make an element difficult to construct. To address those problems, headed bars were developed. Provisions of ACI 318-08 specify the development length of headed bars and ignore the effect of transverse reinforcement based on the background researches. However, if headed bars are used at the cut-off or lap splice, longitudinal reinforcements, which are deformed in flexural members, induce tensile stress in cover concrete and increase the tensile force in the transverse reinforcement. The object of this research is to evaluate the effects of transverse reinforcement on the anchorage capacity of headed bar so anchorage test with variable of transverse rebar spacing was conducted. Specimens, which can consider the behavior at the cut-off, were tested. Test results show that failure of specimen without transverse reinforcement was sudden and brittle with concrete cover lifted and developed stress of headed bars was less than half of yield strength of headed bars. On the other hand, in the specimen with transverse reinforcement, transverse rebar directly resist the load of free-end so capacity of specimens highly increased.

An Overrun Control Method and its Synthesis Method for Real-Time Systems with Probabilistic Timing Constraints (확률적인 시간 제약 조건을 갖는 실시간 시스템을 위한 과실행 제어 및 합성 기법)

  • Kim, Kang-Hee;Hwang, Ho-Young
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.5
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    • pp.243-254
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    • 2005
  • Soft real-time applications such as multimedia feature highly variable processor requirements and probabilistic guarantees on deadline misses, meaning that each task in the application meets its deadline with a given probability. Thus, for such soft real-time applications, a system designer may want to improve the system utilization by allocating to each task a processor time less than its worst-case requirement, as long as the imposed probabilistic timing constraint is met. In this case, however, we have to address how to schedule jobs of a task that require more than (or, overrun) the allocated processor time to the task. In this paper, to address the overrun problem, we propose an overrun control method, which probabilistically controls the execution of overrunning jobs. The proposed overrun control method probabilistically allows overrunning jobs to complete for better system utilization, and also probabilistically prevents the overrunning jobs from completing so that the required probabilistic timing constraint for each task can be met. In the paper, we show that the proposed method outperforms previous methods proposed in the literature in terms of the overall deadline miss ratio, and that it is possible to synthesize the scheduling parameters of our method so that all tasks can meet the given probabilistic timing constraints.

The Effects of a Hospice Palliative Education Program on Perception of Hospice, Attitude to Death, and Meaning of Life in Adults (호스피스 완화 교육 프로그램이 일반 성인의 호스피스 인식, 죽음에 대한 태도 및 삶의 의미에 미치는 효과)

  • Choi, Gum-Hee;Kwon, Suhye
    • Journal of Hospice and Palliative Care
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    • v.21 no.1
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    • pp.14-22
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    • 2018
  • Purpose: This study examined the effects of a hospice palliative education program for adults on their perception of hospice, attitude towards death, and meaning of life. Methods: This study was a quasi-experimental study with a non-equivalent control group design. Among 43 participants, 22 were assigned to the non-equivalent experimental group and 21 to the control group. The hospice palliative education program comprised 10 three-hour sessions, each given once a week. Data were analyzed by descriptive statistics, t-test and ${\chi}^2-test$ using SPSS version 20.0. Results: Significant differences between the experimental and control groups were observed in their perception of hospice (t=6.63, P<0.001), attitude towards death (t=2.36, P=0.023), and meaning of life (t=5.06, P<0.001). Conclusion: The results indicate that this education program could positively affect the perception of hospice, attitude toward death, and meaning of life in adults. More studies are warranted to explore the effects of this education program for various age groups so that it may help more people get positive understanding of hospice palliative care. The results suggest this program could help improve the negative perception of hospice, negative attitude towards death and meaning of life that are generally held by the public.

Evaluation of Minimum Spiral Reinforcement Ratio of Circular RC Columns (철근콘크리트 원형기둥의 나선철근 최소철근비에 대한 평가)

  • Kim, Young-Seek;Kim, Hyeong-Gook;Park, Cheon-Beom;Kim, Sang-Woo;Kim, Kil-Hee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.6
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    • pp.1-9
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    • 2017
  • Spiral reinforcement in a circular column plays an effective role in the ductile behavior of a column through position fixing and buckling restraining of the longitudinal reinforcement, and confining core-concrete. Each country has suggested the minimum volumetric ratio of spiral reinforcement in order to secure the ductility of concrete columns. The minimum volumetric ratio of spiral reinforcement suggested by ACI 318-14 and the national concrete structure design standard was developed based on the theory of Richard et al. (1928); furthermore it has been used until now. However, their theory cannot consider the effects of high strength concrete and high strength reinforcement, and arrangement condition of the spiral reinforcement. In this study, a modified minimum volumetric ratio equation is suggested, which is required to improve the ductility of reinforced concrete circular columns and to recover their stress. The modified minimum volumetric ratio equation suggested here considers the effect of the compressive strength of concrete, the yield strength of spiral reinforcement, the cross sectional area of columns, the pitch of spiral reinforcements and the diameter of spiral reinforcement. In this paper, the validity of the minimum volumetric ratios from ACI 318-14 and this study was investigated and compared based on the results of uniaxial compression experiment for specimens in which the material strength and the spiral reinforcements ratio were used as variables. In the end of the study, the modification method for the suggested equation was examined.

Evaluation of at Rest Lateral Stress Coefficient Influenced by Particle Condition (입자의 조건에 따른 정지토압계수 평가)

  • Lee, Jung-Hwoon;Lee, Dong-Ryeol;Yun, Tae-Sup;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.28 no.8
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    • pp.21-29
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    • 2012
  • At-rest lateral stress coefficient that is used for the evaluation of geotechnical structures such as foundations and retaining walls plays a significant role in the analysis and design, as a state variable of in-situ stress condition. In the widely applied Jaky's Ko equation stress condition can be inferred from the internal friction angle obtainable from the laboratory experimentation whereas the eguation mares it challenging to evaluate the influences and criteria of particle characteristics which is essential for the application of friction angles in practices. Thus, this study experimentally explored the behaviors of Ko depending on the relative density, particle shape, and surface roughness effect during a range of loading stages. The Ko values of Jumumjin sand, glass beads, and etched glass beads were measured using a customized Ko device housing strain gauges during loading-unloading-reloading steps, and the effect of dominant factors on Ko is analyzed. Results show that the high Ko prevails for both round and angular specimens with low relative density and the surface roughness has a nominal effect. The angular particles exhibit low Ko for specimens with similar relative density. The characteristics of relevance between Ko and friction angles with varying relative density are also investigated based on the experimental results using empirical correlations and previously reported values.