• Title/Summary/Keyword: Critical section

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A Study on the Alliance Partner Selection Criteria and Performance in Korean Venture Companies (벤처기업의 기술제휴 파트너 선정기준 및 성과에 관한 연구)

  • Kim, Hwan-Jin
    • Journal of Korea Technology Innovation Society
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    • v.17 no.3
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    • pp.540-562
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    • 2014
  • Although the impact of technological partner selection on the success of technological alliance is critical, little attention has been paid to the area of technological alliance partner selection criteria and the relationship between partner selection criteria and success factors of alliance. This study bridges this gap by understanding previous studies of general alliance partner selection criteria such as marketing, international, logistics and production alliances. I drew technological alliance partner selection criteria using AHP method with 12 experts who are currently in charge of technological alliance activities at Korean Venture Companies. This study found 4 criteria such as 'task-related', 'partner-related', 'learning-related', 'risk-related' criteria with 14 items and the relative importance of technological alliance partner selection showed as follows: 'risk-related', 'learning-related', 'partner-related', 'task-related' criteria. In order to test the relationship between technological partner selection criteria and performance, I used 215 survey data of Korean Venture Companies. The results showed that 'partner-related' and 'task-related' criteria had strong positive impacts on the success of technological alliance. Further, I put 4 moderating variables into the study model in order to see their moderating effects. However, no moderating variable showed significant effects. In conclusion section, I discussed the findings and implications of this study and directions for future studies.

CT Number Measurement of Residual Foreign Bodies in Face (안면부에 잔류된 다양한 이물질을 측정한 CT 계수)

  • Wee, Syeo Young;Choi, Hwan Jun;Kim, Mi Sun;Choi, Chang Yong
    • Archives of Plastic Surgery
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    • v.35 no.4
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    • pp.423-430
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    • 2008
  • Purpose: Computed tomography theoretically should improve detection of foreign bodies and provide more information of adjacent soft tissues. And the CT scanner and PACS program proved to be an excellent instrument for detection and localization of most facial foreign bodies above certain minimum levels of detectability. The severity of injury in penetrating trauma to the face, it is often underestimated by physical examination. Diagnosis of a retained foreign object is always critical. Methods: From March, 2005 to February 2008 a study was done with 200 patients who had facial trauma. Axial and coronal CT images were obtained with a General Electric(Milwaukee, Wis) 9800 CT scanner at 130 kV, 90 mA, with a 2-mm section thickness and a $512{\times}512$ matrix. Results: Axial and coronal CT images at various window widths should be used as the first imaging modality to detect facial foreign bodies. The attenuation coefficients for the metallic and nonmetallic foreign bodies ranged from -437 to +3071 HU. As a general rule, metallic foreign bodies produced more Hounsfield artifacts than nonmetallic foreign bodies, thus providing a clue to their composition. All of the metallic foreign bodies were represented by a single peak and had a maximum attenuation coefficient of +3071 HU. Of the nonmetallic foreign bodies, glass had an attenuation coefficient that ranged from +105 to +2039, while plastic had a much lower coefficient that ranged from -62 to -35. wood had the lowest range of attenuation coefficients: -491 to -437. Conclusion: The PACS program allows one to distinguish metallic from nonmetallic foreign bodies and to individually identify the specific composition of many nonmetallic foreign bodies. This program does not, however, allow identification of the specific composition of a metallic foreign body. We recommend this type of software program for CT scanning of any patient with an injury to the face in which a foreign body is suspected.

A Study of the Analysis on the Accident Reduction Effect of the Median (중앙분리대의 사고감소효과 분석에 관한 연구)

  • 김경석;강승림
    • Journal of Korean Society of Transportation
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    • v.21 no.2
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    • pp.45-60
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    • 2003
  • A median is a safety feature most commonly used to separate opposing traffic on a divided highway. In designing highways, the selection and installation of a median can be a critical part from a safety viewpoint because road crossing accidents are definitely more serious than other accidents. In regard to the important function of the median. the proper countermeasure ought to have been provided and thorough study should have been carried out. In this paper, traffic accident data are analyzed to examine the accident reduction effect of the median, which are gathered from all over 4-lane national roads in Korea. The traffic accident data were categorized into two groups by the existence of a median. For more effective analysis, the data have been classified by accident type, severity. and occurrence time. To compare the effectiveness of median installation, not only the accident frequency but also the accident severity, EPDO. and the occupancy rate of specific accidents have been used as a mode of effectiveness. The analysis of the effectiveness of medians shows that both the accident frequency and the accident severity could decrease by providing a median. Also the section where a median was supplied showed the improvement of overall safety through fewer serious and fatal crashes as well as fewer head-on crashes. Therefore, conclusions can be drawn from results of this study that the median installation is an important means to increase the safety of over 4-lane national roads. This study is expected to provide the reasonability of the median installation by identifying the reduction of traffic accident after the median installation and to play a major role in selecting sections where the median is to be offered.

A Study on the Value Expression of the Multinational Corporation Advertisements advanced into Korea - especially on newspaper advertisements - (국내 진출 다국적기업 광고물의 가치표현연구 - 신문광고를 중심으로 -)

  • 정창준
    • Archives of design research
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    • v.16 no.1
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    • pp.103-116
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    • 2003
  • As the globalization become the main stream in our world, there is no exception also on the cultural section. And we are En the midst of this rapid transition. In the case of advertising market, we opened to those agencies in abroad in the early year of 1990 and now completely opened. On this thesis, the multinational corporation advertising was studied and researched by empirical case study. The main topic is the value expression in the advertising creativity viewed on the cultural level. The multinational corporations that have an eminent, powerful brands produces much of goods wend widely with their powerful brands and extend their marketing activities to abroad. For example, those non-alcoholic beverages, pharmaceutical products, cosmetics, electronic appliances, vehicles, sports shoes, clothes are their main exports, and they broaden the product category, market size to the global market. They also use an expert marketing skill accumulated for a long time. The advertising activities is one of the useful method to extend their global market abroad enhacing continuously brand value. And much of the multinational corporation's advertising are suspected of negative effects that advertisements works on a tool which curies so called uniformed ideology - various ruling ideology - with commercial messages. These advertising affect an developing country's moral value, life style, social value, and others. And they weaken those developing country's unique tradition, culture by putting their own ideology. Those who have a critical position on the advertising activities have been careful in judging it's effects. The result of this study which of the value system is expressed in the multinational corporation's advertisements are; First, the self - esteem value is classified by western value, and it was founded out much more in the domestic corporation's advertisements then multinational ones. Second, the security value system is classified by western value system, and it's outcome was much the same as former one. Consequently, the multinational corporation's advertisements have less of an western value expression relative to korean advertisements. Those outcomes may infer that the multinational corporations prefer to an compromise creative strategy in korea for avoiding cultural conflicts.

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The Maintenance Process Model using BPMN Method in Public Rental Housing (BPMN 방식을 이용한 공공임대주택 유지관리 업무 프로세스 모델)

  • Park, Kyung-Mo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.743-751
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    • 2016
  • It is critical to effectively change the measures of prevention from the breakdown maintenance proceeding an apartment housing maintenance task scope. It is necessary that systematization be performed for a series of tasks, such as facility inspection, diagnosis and replacement. In addition, it is preceded by establishing a standardization for maintenance work scope. Therefore, this study examined the problems related to public rental housing maintenance work scope to manage it more systematically. In addition, the study suggests a work process section for facility repairs, long term replacement and general maintenance using one on one interviews with experts to classify the occupants, management office and head office. This study's standard work system is expected to provide fairness and transparency in addition to improving the productivity in public rental housing maintenance via an efficiency promotion plan. In addition, it is used as the basic reference for developing a system of public rental housing maintenance costs and diagnosis actions. Finally, it is necessary to create improvements that provide a more objective work system standardization throughout the analysis of the productivity data according to the work flow and the review of the occupants, management office and head office in the future applications of the pilot site.

The Deformation and Breaking Load of the Fishing Hook by the Tensile Test (인장시험에 의한 낚시의 변형과 파단하중)

  • KO Kwan-Soh;KIM Yong-Hae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.269-275
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    • 1981
  • The fishing hooks were tested for breaking and unbending due to plastic deformation of the material. Study of tensile test is not complicated, but has not even worked out fully enough, especially when the test specimen is subjected to plastic deformation. The fishing hook is subjected to unbending stress and the critical section is a Point which is furthest from the line of action of the forces. The dynamic force of fish during jerks depends on their speed of movement and body weight, the kinetic energy corresponding to it and also on the rlastic displacement of the rigging which absorb the energy. Six kinds of hook were tested by the dynamometer under tensile speed 290mm/min (subscript s) and 780mm/min (subscript f). According to their results, the breaking load(B: kg) can be induced with the formula $B={\alpha}wd^2+\beta$ where w(mm) is the distance between the barb base and the lower shank and d(mm) is diameter. The coefficients of the formula for the round hooks(R) and the angular hooks(A) are approximately as follows: $$R:\;\alpha_{s}=0.5,\;\beta_{s}=1.6,\;\alpha_{f}=0.4,\;\beta_{f}=1.4$$ $$A:\;\alpha_{s}=1.1,\;\beta_{s}=2.0,\;\alpha_{f}=1.0,\;\beta_{f}=0.9$$ The ratio of $B_{f}\;to\;B_{s}$ is corresponding to 0.8. The ratio of deformation(X) that is moved distance of barb base at break to the distance(H) between head base and barb base is about $50\%$. Further study should be carried out on the subject of impact and fatigue test under the same condition which is exerted force by the hooked fish.

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Numerical Simulation of Cavitating Flows on a Foil by Using Bubble Size Distribution Model

  • Ito, Yutaka;Nagasaki, Takao
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.216-227
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    • 2004
  • A new cavitating model by using bubble size distribution based on bubbles-mass has been proposed. Both liquid and vapor phases are treated with Eulerian framework as a mixture containing minute cavitating bubbles. In addition vapor phase consists of various sizes of vapor bubbles, which are distributed to classes based on their mass. The bubble number-density for each class was solved by considering the change of the bubble-mass due to phase change as well as generation of new bubbles due to heterogeneous nucleation. In this method, the bubble-mass is treated as an independent variable, and the other dependent variables are solved in spatial coordinates and bubble-mass coordinate. Firstly, we employed this method to calculate bubble nucleation and growth in stationary super-heated liquid nitrogen, and bubble collapse in stationary sub-cooled one. In the case of bubble growth in super-heated liquid, bubble number-density of the smallest class based on its mass is increased due to the nucleation. These new bubbles grow with time, and the bubbles shift to larger class. Therefore void fraction of each class is increased due to the growth in the whole class. On the other hand, in the case of bubble collapse in sub-cooled liquid, the existing bubbles are contracted, and then they shift to smaller class. It finally becomes extinct at the smallest one. Secondly, the present method is applied to a cavitating flow around NACA00l5 foil. Liquid nitrogen and liquid oxygen are employed as working fluids. Cavitation number, $\sigma$, is fixed at 0.15, inlet velocities are changed at 5, 10, 20 and 50m/s. Inlet temperatures are 90K in case of liquid nitrogen, and 90K and 1l0K in case of liquid oxygen. 110K of oxygen is corresponding to the 90K of nitrogen because of the same relative temperature to the critical one, $T_{r}$=$T/T_c^{+}$. Cavitating flow around the NACA0015 foils was properly analyzed by using bubble size distribution. Finally, the method is applied to a cavitating flow in an inducer of the LE-7A hydrogen turbo-pump. This inducer has 3 spiral foils. However, for simplicity, 2D calculation was carried out in an unrolled channel at 0.9R cross-section. The channel moves against the fluid at a peripheral velocity corresponding to the inducer revolutions. Total inlet pressure, $Pt_{in}$, is set at l00KPa, because cavitation is not generated at a design point, $Pt_{in}$=260KPa. The bubbles occur upstream of the foils and collapse between them. Cavitating flow in the inducer was successfully predicted by using the bubble size distribution.

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Evaluation of Shear Capacity on PC Girder-PC Beam Joint (PC 큰 보-PC 작은 보 접합부의 전단성능 평가)

  • Moon, Jeong Ho;Oh, Young Hun;Lim, Jae Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.166-174
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    • 2011
  • The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.

An Analytical Review on the Inelastic Region of Column Strength Curve Associated with Residual Stress of Steel Member under Axial Force (강 압축 부재의 잔류응력에 따른 기둥강도곡선의 비탄성영역에 대한 해석적 고찰)

  • See, Sang-Kwang
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.2
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    • pp.161-168
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    • 2018
  • This study is the analytical review on the inelastic region of CRC column strength curve. The inelastic region of CRC column strength curve is based on the Bleich theory and the maximum residual stress of $0.5{\sigma}_y$. This is somewhat conservative by considering the fact that the maximum residual stress of $0.3{\sigma}_y$ is well known. This study proposes column strength curve for nonlinear behavior of hot rolled structural steel members under axial force and tangent modulus Et, with the maximum residual stress of $0.3{\sigma}_y$ and compares them with those of CRC. The stress of the inelastic column under axial compression exceeds proportional limits and reaches yielding point before applied load render the column bent. The column strength curve that depends on gradually yielding state of section needs to be reviewed. In this study, it is derived that the critical load formular according to material yielding with the maximum residual stress of $0.5{\sigma}_y$ and compared with CRC column design curve.

The Response Prediction of Flexible Pavements Considering Nonlinear Pavement Foundation Behavior (비선형 포장 하부 거동을 고려한 연성 포장의 해석)

  • Kim, Min-Kwan
    • International Journal of Highway Engineering
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    • v.11 no.1
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    • pp.165-175
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    • 2009
  • With the current move towards adopting mechanistic-empirical concepts in the design of pavement structures, state-of-the-art mechanistic analysis methodologies are needed to determine accurate pavement responses, such as stress, strain, and deformation. Previous laboratory studies of pavement foundation geomaterials, i.e., unbound granular materials used in base/subbase layers and fine-grained soils of a prepared subgrade, have shown that the resilient responses followed by nonlinear, stress-dependent behavior under repeated wheel loading. This nonlinear behavior is commonly characterized by stress-dependent resilient modulus material models that need to be incorporated into finite element (FE) based mechanistic pavement analysis methods to predict more realistically predict pavement responses for a mechanistic pavement analysis. Developed user material subroutine using aforementioned resilient model with nonlinear solution technique and convergence scheme with proven performance were successfully employed in general-purpose FE program, ABAQUS. This numerical analysis was investigated in predicted critical responses and domain selection with specific mesh generation was implemented to evaluate better prediction of pavement responses. Results obtained from both axisymmetric and three-dimensional (3D) nonlinear FE analyses were compared and remarkable findings were described for nonlinear FE analysis. The UMAT subroutine performance was also validated with the instrumented full scale pavement test section study results from the Federal Aviation Administration's National Airport Pavement Test Facility (FAA's NAPTF).

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