In this study, we examined dimensional changes in processing carbon fiber composites using a cost-competitive domestic high-speed router. Lacking temperature compensation features found in typical machines, it faces increased defect rates due to temperature fluctuations during processing. To mitigate this, we defined specific processing temperature conditions, established hole positions as distance references for various temperatures, and measured dimensional changes. This enabled us to calculate necessary dimensional corrections, minimizing thermal deformation.

In this experiment, the error according to the measurement method was analyzed for the length, angle, radius of curvature, and diameter of the measurement system analysis using a profile projector device used in the field. One-way analysis was performed on each data tested 30 times using a statistical technique. Through the experiment, it was found that an error occurred in each data when measuring the angle according to the measurement method, and the null hypothesis that no error occurred when measuring the length, inside dia and radius was established.

The present study identified several antecedents that create perceived resistance to supply chain management (SCM) change. This work particularly emphasizes SCM change, which is notable given its central role in reacting market orientation and varied environmental and managerial conditions. A careful case study on a small and medium sized food production company in South Korea leads to the formulation of our framework including one second-order construct of ‘resistance’ as well as eight first-order constructs of ‘implementing the payment terms’, ‘balancing of business process’, ‘fear of responsibility’, ‘business sustainability transparency’, ‘past experience of failure’, ‘competence of work personnel’, ‘cooperation with third parties’ and ‘sharing personnel information with partner’. The hypothesized relation of first- and second-order construct was validated using survey sample data collected from 350 respondents who completed their questionnaire instrument. Results from confirmatory factor analysis revealed that nomological validity was established at statistical significance level by identifying six first order constructs of ‘implementing the payment terms’, ‘fear of responsibility’, ‘business sustainability transparency’, ‘past experience of failure’, a conbined construct of 'competence of work personnel/ cooperation with third parties’ and ‘sharing personnel information with partner’. The findings from our work are expected to provide important insights to the strategy for SCM risk management for small and medium sized company.

Dimensional accuracy is one of the most important issues in the production of sintered parts. The iron-copper-carbon system is commonly used alloys in sintered structural parts production. The dimensional control of these alloys, however, is not easy because of their complex sintering behavior. This study is an effort to clarify the influence of common factors on dimensional change of Fe-Cu-C sintered structural parts. We determined the effect of such various parameters as chemical composition, particle diameter, compact density, sintering temperature and sintering time on dimensional changes. Consequently, we obtained a useful formula to predict the final dimension in function of these parameters. The effect of typical impurities in copper powder on the dimensional change of sintered parts has also been described.

The W-Cu composite powders were synthesized from W and Cu elemental powders by ball-milling process, and their microstructural changes and sintering behaviors were evaluated. The ball milling process was carried out in a 3-dimensional mixer (Turbula mixer) using zirconic () ball and alumina () vial up to 300 hrs. The ball-milled W-Cu powders revealed nearly spherical shape. Microstructure of the composite powders showed onion-like structure which consists of W and Cu shells due to the moving characteristic of Turbula mixer. The W and Cu elements in the composite powders milled for 300 hrs were homogeneously distributed, and W grain size in the ball-milled powder was smaller than 0.5 . Fe impurity introduced during ball milling process was very low as of 0.001 wt%. The relative sintered density of ball-milled W-Cu specimens reached about 94% after sintering at .

본 연구에서는 4대강 살리기 사업 후 퇴적현상이 지배적으로 발생하는 남한강과 섬강 합류부 구간을 대상으로 2차원 수치모형인 CCHE2D 모형을 이용하여 하천의 흐름 및 하상변동에 대한 해석을 수행하였다. 대상지점 합류부는 남한강 본류의 만곡부에 지류 섬강이 유입되는 특성을 갖는다. CCHE2D 모형은 비평형 유사이송을 해석하며 소류사와 부유사 조정거리가 중요한 입력변수로 대상지점에서는 소류사 조정거리가 하상변동에 가장 큰 영향을 주는 것으로 나타났다. 수치모의 결과 유량비(Qr) 변화가 남한강과 섬강 합류부 지점에서 흐름 및 하상변동에 영향을 미쳤으며, Qr≤ 2.5인 경우에는 합류전 본류의 유속이 증가하여 흐름박리구역을 감소시켰으며 이로 인해 합류부 내측의 퇴적이 감소하였다. Qr>2.5이면 합류부 구간에 퇴적이 증가하여 사주가 형성될 가능성이 높은 것으로 나타났다. 수치모의를 통해 2013년에 발생한 유량비 변화에 의해 합류부에 고정사 주가 형성된 것을 알 수 있었다.

The stability of the river in the restored river is an important issue in maintenance and management. Bed elevation change simulation can be an effective way to predict the direction of river restoration by predicting long and short term bed elevation change of river. A 2D numerical model (CCHE2D) was implemented to simulate the long-term bed elevation change. The study area is located in the Cheongmi-Cheon Notap-ri and 1.2 km long. The flow scenario was constructed using the flow data that was measured at the water level observatory located upstream at the Janghowon Bridge. The bed elevation change pattern according to restoration of abandoned channel was analyzed and the stability of river was evaluated.

최근 기후변화로 인하여 재해의 빈도 및 강도가 급격하게 증가하는 등 기후변화 리스크가 증대되고 있다. 뿐만 아니라 사회·경제적 리스크와 중첩되어 매우 극단적인 양상을 보이는 등, 재난관리에 있어 기후변화 리스크를 체계적으로 관리하는 것이 핵심과제로 떠오르고 있다. 이에 따라 호주 및 영국을 비롯한 국가에서 기후변화 리스크 관리프로세스를 마련·제시하고 있다. 기후변화 리스크는 리스크 요인별·적응주체별로 주체가 겪는 리스크 영향이 달라지기 때문에, 기후변화 리스크관리프로세스 상에 기후변화 리스크 요인과 적응주체, 그리고 그 영향을 반영하여 다차원적으로 접근할 필요가 있다. 그러나 기존에 제시된 리스크 관리프로세스는 기후변화에 따른 요인별· 적응주체별· 기후변화영향을 파악하고 평가하는 측면에서 단편적으로 접근하고 있다. 또 리스크 평가와 리스크관리를 위한 정책대안을 평가하고 선택하는 단계와의 연계성이 떨어져 실질적인 역할을 기대하기 어려운 측면이 있다. 따라서 본 연구에서는 본 연구에서는 기후변화에 따른 직·간접적 리스크를 구분하고 리스크 적응주체의 특성을 반영할 수 있는 다차원적 리스크 관리 프레임워크를 구축하였다. 그리고 이를 지자체 단위의 방재부문에 적용하여 실제 적용가능성을 검토하였다.

금강에 위치한 부여취수장 부근에서의 유사이송을 모의하기 위해서 2차원 유한요소모형(RMA)이 적용되었다. 다양한 유량조건하에서 하상변동에 관한 모의수행결과는 과거 이 지역에서의 실측된 값과 잘 일치하였다. 본 연구에서 하도부의 개선과 취수구 부근의 하상저하를 위한 대안으로서 수제공 설치와 밤섬제거가 고려되었다. 수제공의 설치에 다라 좌안쪽으로 주흐름이 변환되었으며, 전 영역에 걸쳐서 비슷한 폭을 가진 하도가 형성되었다. 12,030{{{{ { m}^{3