• 제목/요약/키워드: capacity change

검색결과 2,184건 처리시간 0.032초

경계연결리더십이 조직구성원의 자기효능감, 역할 외 활동, 그리고 흡수역량에 미치는 영향 (The Effect of Boundary-spanning Leadership on Self-efficacy, Extra-role Behavior, and Absorptive Capacity)

  • 권정언;우형록
    • 지식경영연구
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    • 제20권1호
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    • pp.133-153
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    • 2019
  • Due to the uncertainty of dynamic business environment, modern organizations have been giving attention to dynamic capabilities beyond traditional notion of core competence. Among them, absorptive capacity and boundary-spanning activity are considered the most important. The former refers to activities regarding acquisition, assimilation, transformation and exploitation of internal and external knowledge. The latter is composed of boundary-loosening and boundary-tightening activities to detect internal or external information and then to preserve, protect, or acquire resources. Thus, both have achieved wide recognition as a potential source of change and innovation. This study investigated the cross-level relation between boundary-spanning leadership at team level and absorptive capacity at individual level. We also explored self-efficacy and extra-role behavior that can affect employees' absorptive capacity. To test multi-level analysis, the survey data were collected from 862 members in 137 teams of different firms. Results revealed that boundary-spanning leadership had the positive cross-level impact on absorptive capacity in the team context. Moreover, absorptive capacity was positively associated with self-efficacy and extra-role behavior at individual level. Based on these findings, we provided theoretical and practical implications to address rapidly changing environments and discussed limitations of this paper for further research.

Evaluations of Si based ternary anode materials by using RF/DC magnetron sputtering for lithium ion batteries

  • 황창묵;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.302-303
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    • 2010
  • Generally, the high energy lithium ion batteries depend intimately on the high capacity of electrode materials. For anode materials, the capacity of commercial graphite is unlike to increase much further due to its lower theoretical capacity of 372 mAhg-1. To improve upon graphite-based negative electrode materials for Li-ion rechargeable batteries, alternative anode materials with higher capacity are needed. Therefore, some metal anodes with high theoretic capacity, such as Si, Sn, Ge, Al, and Sb have been studied extensively. This work focuses on ternary Si-M1-M2 composite system, where M1 is Ge that alloys with Li, which has good cyclability and high specific capacity and M2 is Mo that does not alloy with Li. The Si shows the highest gravimetric capacity (up to 4000mAhg-1 for Li21Si5). Although Si is the most promising of the next generation anodes, it undergoes a large volume change during lithium insertion and extraction. It results in pulverization of the Si and loss of electrical contact between the Si and the current collector during the lithiation and delithiation. Thus, its capacity fades rapidly during cycling. Si thin film is more resistant to fracture than bulk Si because the film is firmly attached to the substrate. Thus, Si film could achieve good cycleability as well as high capacity. To improve the cycle performance of Si, Suzuki et al. prepared two components active (Si)-active(Sn, like Ge) elements film by vacuum deposition, where Sn particles dispersed homogeneously in the Si matrix. This film showed excellent rate capability than pure Si thin film. In this work, second element, Ge shows also high capacity (about 2500mAhg-1 for Li21Ge5) and has good cyclability although it undergoes a large volume change likewise Si. But only Ge does not use the anode due to its costs. Therefore, the electrode should be consisted of moderately Ge contents. Third element, Mo is an element that does not alloys with Li such as Co, Cr, Fe, Mn, Ni, V, Zr. In our previous research work, we have fabricated Si-Mo (active-inactive elements) composite negative electrodes by using RF/DC magnetron sputtering method. The electrodes showed excellent cycle characteristics. The Mo-silicide (inert matrix) dispersed homogeneously in the Si matrix and prevents the active material from aggregating. However, the thicker film than $3\;{\mu}m$ with high Mo contents showed poor cycling performance, which was attributed to the internal stress related to thickness. In order to deal with the large volume expansion of Si anode, great efforts were paid on material design. One of the effective ways is to find suitably three-elements (Si-Ge-Mo) contents. In this study, the Si based composites of 45~65 Si at.% and 23~43 Ge at.%, and 12~32 Mo at.% are evaluated the electrochemical characteristics and cycle performances as an anode. Results from six different compositions of Si-Ge-Mo are presented compared to only the Si and Ge negative electrodes.

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대리변수를 이용한 한반도 수질 및 수생태계 부문의 기후변화 취약성 평가 (Vulnerability Assessment of Water Quality and Aquatic Ecosystem to Climate Change in Korea using Proxy Variables)

  • 이건행;정유진;김경현;유정아;이은정
    • 한국물환경학회지
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    • 제28권3호
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    • pp.444-452
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    • 2012
  • This study aims at assessing vulnerability of water quality and aquatic ecosystem to climate change by using proxy variables. Vulnerability to climate change is defined as a function of exposure to climate, sensitivity, and adaptive capacity. Detailed proxy variables were selected considering availability and then standardized by re-scaling concept. After adequate weights were assigned to standardized proxy variables by Delphi technique, vulnerability index was calculated. As results, vulnerability of adjacent regions to coastal areas include water quality and aquatic ecosystem is relatively higher than that of inland areas, and especially adjacent region to the western and southeast seas, and Jeju show high vulnerabilities. Vulnerability in the future was performed based on A1B scenario (IPCC, 2000). Temporally, the increase of vulnerability from 2050s to 2100s may be larger than the increase from 2000s to 2050s. Because vulnerability index was estimated through the relationship among various proxy variables, it is important to consider characteristics of local region with measurements and policies for reduction of sensitivity and enhancement of adaptive capacity on climate change. This study is expected to be useful in planning adaptation measures and selecting priority to the policy on climate change.

부산지역 미세먼지에 대한 건강 취약성 평가 (Health Vulnerability Assessment for PM10 in Busan)

  • 이원정;황미경;김유근
    • 한국환경보건학회지
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    • 제40권5호
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    • pp.355-366
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    • 2014
  • Objectives: This study seeks to evaluate the vulnerability assessment of the human health sector for $PM_{10}$, which is reflected in the regional characteristics and related disease mortality rates for $PM_{10}$ in Busan over the period of 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), vulnerability to $PM_{10}$ is comprised of the categories of exposure, sensitivity, and adaptive capacity. The indexes of the exposure and sensitivity categories indicate positive effects, while the adaptive capacity index indicates a negative effect on vulnerability to $PM_{10}$. Variables of each category were standardized by the rescaling method, and each regional relative vulnerability was computed through the vulnerability index calculation formula. Results: The regions with a high exposure index are Jung-Gu (transportation region) and Saha-Gu (industrial region). Major factors determining the exposure index are the $PM_{10}$ concentration, days of $PM_{10}{\geq}50$, ${\mu}g/m^3$, and $PM_{10}$ emissions. The regions that show a high sensitivity index are urban and rural regions; these commonly have a high mortality rate for related disease and vulnerable populations. The regions that have a high adaptive capacity index are Jung-Gu, Gangseo-Gu, and Busanjin-Gu, all of which have a high level of economic/welfare/health care factors. The high-vulnerability synthesis of the exposure, sensitivity, and adaptive capacity indexes show that Dong-Gu and Seo-Gu have a risk for $PM_{10}$ potential effects and a low adaptive capacity. Conclusions: This study presents the vulnerability index to $PM_{10}$ through a relative comparison using quantitative evaluation to draw regional priorities. Therefore, it provides basic data to reflect environmental health influences in favor of an adaptive policy limiting damage to human health caused by vulnerability to $PM_{10}$.

어촌특화 역량강화사업의 성과 및 주민의식 변화분석 (Analysis of the Performance and Change of Resident Consciousness of the Fishing Village Specialization Capacity Enhancement Project through Surveys - Focusing on the Comparative Analysis of Consciousness of Inland Water and Coastal Residents -)

  • 양민호;김기성;고진영
    • 한국농공학회논문집
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    • 제63권2호
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    • pp.19-31
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    • 2021
  • The Ministry of Maritime Affairs and Fisheries has been promoting the 'Fishing Village Specialization Capacity Enhancement Project' to pursue sustainable development of villages such as income generation by using local tangible and intangible resources led by local residents at the village level since 2013. For the fishing village-Specialization capacity enhancement project, six training sessions (mainly in the village unit) are selected by the public offering method, and the project (income generating business, village development project, etc.) is developed for the selected village residents. It has a process of establishing a village project plan (a preliminary plan for village development or a sixth preliminary industrialization plan) based on the training of experts 5 times, practice or excursion 1 time). In this study, four villages in Gangwon-do fishing villages (two coastal villages and two inland water villages) were surveyed on the perception and satisfaction of fishing village development projects before and after training. The survey analysis was conducted by dividing the analysis of resident capacity and satisfaction into personal, interpersonal, and social dimensions. The survey was conducted by distributing a survey before and after training, and a 1:1 survey was conducted according to the residents' cognitive status. Based on the survey, factor analysis, reliability analysis, and analysis using the corresponding sample t-test showed an increase of 0.02 for Yangyang Mulchi fishing village, 0.11 for Samcheok Jangho fishing village, and 0.36 for Hongcheon River fishing industry, but Yanggu Jinmok fishing industry was -0.29, unlike other regions. As a result of this analysis, it has been empirically proven that provision of training projects through resident participation is a very important factor for the success of the fishing village project. Therefore, rather than fostering local leaders, training and community activities to strengthen personal capacities of residents participating in the project, it is necessary to operate the software business with a focus.

Grooved butterfly valve의 형상 변화에 따른 용량계수 평가에 관한 연구 (A study on flow coefficient evaluation by shape change of butterfly valve)

  • 이정원;신봉철;조용규;조명우;이강희
    • 한국산학기술학회논문지
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    • 제13권11호
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    • pp.4937-4943
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    • 2012
  • 버터플라이 밸브는 다른 밸브에 비해 작동의 용이성으로 각종 산업에서 유량 조절을 목적으로 많이 활용되고 있다. 버터플라이 밸브를 통과하는 유량을 제어하기 위해서는 디스크 각에 따른 용량계수에 따라 유량을 제어하게 된다. 본 논문에서는 고품질 밸브 제작을 위해 성능 지표 중에 하나인 용량계수를 기존의 제품의 3D 모델을 이용하여 유동 해석 및 분석을 수행하였고 이를 검증하기 위해 용량계수 측정 장비 측정을 통해 해석의 신뢰성을 확인하였다.

피복된 미립 상변화물질 슬러리를 이용한 대류 열전달의 향상에 관한 연구 (Enhancement of Convective Heat Transfer by Using a Micro-Encapsulated Phase-Change-Material Slurry)

  • 정동주;최은수
    • 대한기계학회논문집B
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    • 제24권9호
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    • pp.1277-1284
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    • 2000
  • To enhance heat transfer characteristics of water, micro-encapsulated octadecane of about $10{\mu}m$ diameter was added to water. Viscosity of the slurry was measured by using a capillary tube viscometer. The measured viscosity decreased as the temperature of the slurry increased, and it increased as the fraction of the capsules in the slurry increased. Thermal characteristics of the octadecane were studied by using a differential scanning calorimeter. The melting temperature and the melting energy of the octadecane were found to be $28.6^{\circ}$ and 34.4kcal/kg, respectively. The convective heat transfer characteristics of the slurry were investigated in a flow loop with a constant heat flux test section. Friction factor of the slurry flow was found to be similar to the expected curve by Petukhov. The Nusselt number of the slurry flow was highest when the octadecane melted. Effective thermal capacity of the 14.2% slurry was found to have 1.67 times of the thermal capacity of water.

Gait Training Strategy Focusing on Perceptual Learning for Improved Gait Capacity in Stroke Survivors

  • Jung, Jee Woon
    • The Journal of Korean Physical Therapy
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    • 제32권5호
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    • pp.283-289
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    • 2020
  • Objective: The purpose of this study was to determine the force of lower extremities, the change in walking ability on the ground by applying a walking training program based on perceptual learning to improve gait capacity of chronic stroke patients. Method: This study included Twenty-four patients with chronic stroke. Using a perceptual-based gait training, the experimental group trained twice a day for 30 minutes each time, 5 times a week, for a total of 8 weeks. The control group underwent ground gait training that excluded the element of a perceptual training for 30 minutes, 5 times a week for 8 weeks. Results: In the two groups, the maximum forefoot pressure after intervention was significantly different in both the LEPGT and GGT (p<0.05). The maximum midfoot pressure was significantly different in LEPGT (p<0.05). There was a significant difference in the maximum heel pressure after intervention between the two groups (p<0.05). As a result of comparing the change in step length and stride length after intervention in the two groups, there was a significant difference between the two groups (p<0.05). Conclusion: Both gait training programs was found that gait training based on perceptual learning and ground gait training were the training for improving the functional gait of stroke patient. Perceptual learning gait training utilizing intensive perceptual awareness was the training for improving gait capacity within the period than ground gait training.

Behavior of polygonal concrete-filled steel tubular stub columns under axial loading

  • Zhang, Tao;Ding, Fa-xing;Wang, Liping;Liu, Xue-mei;Jiang, Guo-shuai
    • Steel and Composite Structures
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    • 제28권5호
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    • pp.573-588
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    • 2018
  • The objective of this paper is to investigate the mechanical performances of polygonal concrete-filled circular steel tubular (CFT) stub columns under axial loading through combined experimental and numerical study. A total of 32 specimens were designed to investigate the effect of the concrete strength and steel ratio on the compressive behavior of polygonal CFT stub columns. The ultimate bearing capacity, ductility and confinement effect were analyzed based on the experimental results and the failure modes were discussed in detail. Besides, ABAQUS was adopted to establish the three dimensional FE model. The composite action between the core concrete and steel tube was further discussed and clarified. It was found that the behavior of CFT stub column changes with the change of the cross-section, and the change is continuous. Finally, based on both experimental and numerical results, a unified formula was developed to estimate the ultimate bearing capacity of polygonal CFT stub columns according to the superposition principle with rational simplification. The predicted results showed satisfactory agreement with both experimental and FE results.

투수성 포장체 쇄석 보조기층 지오그리드 보강효과 확인에 대한 연구 (A Study on Effect of Geogrid Reinforced- Crushed stone Sub-base in Permeable Pavement System)

  • 권혁민;오정호;한신인
    • 복합신소재구조학회 논문집
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    • 제6권4호
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    • pp.64-70
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    • 2015
  • A rapid urbanization has increased the portion of paved layer that results in the change of water circulation system. This change leads to frequent events of flooding, drought, and urban heat island. To resolve these issues, permeable pavement system based on Low Impact Development (LID) concept is being applied to international urban areas. Therefore it is necessary to establish a rational design procedure for the permeable pavement system that reflects our environmental conditions. iDue to inherent characteristics of permeable pavement system, water infiltrates thorough the layers so it may reduce the bearing capacity of sub-layers. In this study, an effort was made to investigate the effectiveness of geogrid reinforced crushed stone subbase layer based on field experimental program along with a limited numerical analysis. It reveals that geogrid reinforced sections improve the bearing capacity by close to 20%. In addition, a light weight deflectomenter (LWDT) appears to be promising for the compaction quality control of crushed stone subbase layer in order to construct qualified permeable pavement systems.