In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the “Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges.” Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

In this analysis, the analytical model was verified through the normal mode analysis of the piston for the 2.9 liter IDI (indirect injection) engine. Heat transfer analysis was carried out by selecting two cases of applied temperature using the validated model. The first case was a condition of 350℃ on the piston upper surface and 100℃ on the piston body and inner wall. In the second case, the conditions were set to give a temperature of 400℃ on the upper surface of the piston and 100℃ on the piston body and the inner wall. In addition, the temperature distribution due to heat transfer was obtained for the pistons with boundary conditions of two cases, and then the thermal stress distribution due to thermal expansion was obtained using the input. Using this analysis result, the thermal stress caused by thermal expansion due to the thermal conduction of the piston is examined and used as the basic data for design.

Statistical analysis for the 703 air purifiers certified by Korea Air Cleaning Association from 2003 to 2019 was performed. Sixty-one percent of the products had an area coverage of 15 m2~30 m2 and the median value of the total products was 37.6 m2. The number of certified products by the top five manufacturers was 325, which corresponds to 46.2% of the total products. The median value of the clean air delivery rate (CADR) of the 703 products was 4.8 m3/min but the number of air purifiers over the value increased to 62.5%~66.3% since 2018. The odor removal ratio showed a median of 86.0% which was higher than the certification criteria but had large differences in efficacy in the five test compounds. Removal efficiencies of each compound in terms of the median and ratio to the average value showed acetate > formaldehyde > toluene > ammonia > acetaldehyde in descending order with large variances. The median noise level average value from five positions of air purifiers was 47.7 dB(A). However the medians of the top position and the front, where purified air was vented out, were relatively higher in 49.8 dB(A) and 48.2 dB(A), respectively. Noise level ratio to noise criteria had a median value of 96.4%, which showed that most of the noise levels were distributed near the criteria limit. The probability of the noise level at 100% of the criteria was calculated ton 0.232, which indicated excess noise levels.

PURPOSES : Pavement growth (PG) of concrete pavement has been recognized as a major concern to highway and airport engineers as well as to road users for many years. PG is caused by the pressure generation in the concrete pavement as a result of a rise of the concrete temperature and moisture. PG could result in concrete pavement blowup and damage the adjacent or the nearby structures such as bridge structures. The amount of the PG is affected by the complicated interactions of numerous factors such as climatic condition, amounts of incompressible particles (IP) infiltration into the joints, pavement structure, and materials. Trigger temperature for pavement growth (TTPG) is defined as the concrete temperature when all transverse cracks or joints within the expansion joints completely close and generating a pressure in the pavement section. It is one of the most critical parameters to evaluate the potential of PG occurring in the pavement. Unfortunately, there are no available methods or guidelines for estimating TTPG. Therefore, this study aims to provide a methodology to predict TTPG of a concrete pavement section. METHODS : In this study, a method to evaluate the TTPG and its influencing factors using the field measured data of concrete pavement expansions is proposed. The data of the concrete pavement expansions obtained from the long-term monitoring of three concrete pavement sections, which are I-70, I-70N, and Md.458, in Maryland of United Stated, were used. The AASHTO equation to estimate the joint movement in concrete pavement was used and modified for the back-calculation of the TTPG value. A series of the analytical and numerical solutions presented in the literatures were utilized to predict the friction coefficient between the concrete slab-base and to estimate the maximum concrete temperature of these three pavement sections. RESULTS : The estimated maximum concrete temperature of these three pavement sections yearly exhibited relatively constant values, which range from 40 to 45 °C. The results of the back-calculation revealed that the TTPG of the I-70 and Md.58 sections decreased with time. However, the TTPG of the I-70N section tended to be relatively constant from the first year of the pavement age. CONCLUSIONS : The estimation of the TTPG for the three concrete pavement sections showed that the values of the TTPG gradually decreased although the yearly maximum concrete pavement temperature did not change significantly.

피노체트 군사정부가 고안한 칠레의 2석선거구 제도는 비례대표제이 지만 의석배분방식이 매우 독특한 선거제도이다. 민주화 이후에도 우파 의 영향력을 이어가고자 만들어낸 선거제도로 비민주성, 불비례성, 지 역대표성, 소수정당의 의회진입 어려움이라는 문제를 지적받아왔다. 2015년 미첼 바첼렛 정부는 2석선거구 제도를 폐지하고 새 선거법을 도입했다. 선거구를 조정하고, 의원 정수를 확대하였으며, 의석 배분 방식을 바꾸었다. 선거법 개정 이후 첫 선거인 2017년 선거 결과 농촌 지역의 과다대표성은 도시지역의 과다대표로 전환되었고, 중대선거구제 도입으로 소수정당과 여성의 의회진출이 다소 늘어났다. 양당체계는 다 당체계로 전환되었고, 동트 방식으로 의석배분을 하여 차순위 당선자가 낙선할 수도 있는 2석선거구 제도의 비민주성을 해소하였으나, 불비례 성에 있어서는 2석선거구제도와 비교했을 때 나아지지 않았다. 일반적 인 중대선거구보다 선출 의원 수가 많고, 개방형 명부를 제출하지만 정 당득표율에 따라 의석을 배분하기 때문에 대정당의 의석확보율이 득표 율보다 높게 나타났고, 특히 우파연합의 의석전환율은 2석선거구 제도 보다 높았다.

본 연구는 훼손된 하천 수생태계의 훼손원인을 식별하고 그 전이 과정을 규명하기 위해 수생태계 훼손원인 진단체계를 구축하고 정책적 활용 가능성을 보고자 하였다. 수생태계 현황 조사 및 건강성 평가결과는 하천의 훼손에 대한 전반적인 상황을 알 수 있어 하천 복원 및 관리의 판단 근거로 사용된다. 그러나 하천이 훼손된 원인이나 훼손이 발생하게 된 전이 과정을 고려하지 못한다는 한계를 가진다. 따라서 본 연구에서는 과학적이고 체계적인 진단체계를 제안하여 훼손원인과 그 전이 과정을 규명하였다. 미국, 호주, 유럽의 사례를 분석하여 우리나라에 맞는 진단체계를 제안하였다. 총 8단계로 구성되며, 기초자료 조사, 하천 수생태계 훼손 판단, 훼손 구간 설정, 훼손 유형화 및 잠재적 훼손원인 도출, 본 조사, 주 훼손원인 진단 및 최적 훼손 모델 도출, 종합분석 및 하천 복원방안으로 이루어져 있다. 이러한 진단체계는 하천 생태계의 복잡하고 다양한 특성을 고려하여 훼손원인을 파악할 수 있으며 하천 복원 및 관리 방안을 제시하여 효율적인 의사결정을 지원할 수 있다.

Innovation activities represented by Six Sigma (6σ) led to improvements not only in manufacturing industries but also in various business fields. In the aviation industry, Six Sigma has been used as a tool of innovation since the beginning of 2000, and it has developed into a comprehensive form of innovation activity that includes various improvement tools. In this study, the innovation activities in K company that is a representative company of aviation industry are summarized in the last 10 years, and the effectiveness of the innovation tools and the performance of the tasks are also analyzed. The results of 2,091 projects over the past decade have been analyzed from various perspectives. First, we found out the tools that were used frequently at each DMAIC step, showed their frequency, and analyzed the evaluation results for the project. The project was evaluated from grade 1 (highest level) to grade 7 (lowest level) with an average grade of 4.1 for the overall project. The evaluation grades of the projects were compared and analyzed in terms of the qualifications of the leader, the roadmap for the implementation of the project, the financial effect, the size of the financial effect, the business classification, and the project execution period. These results may suggest new perspectives for companies considering or adopting innovation programs.

지금까지 진성 리더십 연구들은 한정된 맥락 속(예: 영리 조직)에서만 진행되었으며, 진성 리더십의 개 발 가능성과 선행요인을 확인한 연구는 미흡한 편이다. 따라서 본 연구는 군 조직에서 리더의 자아존중감, 자아 성찰(빈도, 초점, 시간), 인생의미(존재, 탐색)가 리더 자신의 진성 리더십에 미치는 영향과 리더의 진성 리더십이 부하들의 리더에 대한 신뢰, 리더 지향 조직시민행동에 미치는 영향을 실증하는데 목적을 두고 있다. 이를 검증하기 위해 리더 양성 프로그램으로 수양록(일기)을 작성하고 있는 사관학교에서 사관생도 719명(소대장 생도 32명, 분대장 생도 93명, 분대원 생도 594명)을 대상으로 설문조사를 실시하여 실증 분석하였다. 분석결과 자아존중감이 높은 리더, 자아에 대한 반복적인 성찰(수양록 작성의 빈도)을 하는 리더, 현재 자신의 모습을 원인 중심으로 성찰(수양록 작성의 초점)하는 리더가 진성 리더십이 높게 나타났으며, 인생의 의미를 발견한(인생의미 존재) 리더 역시 진성 리더로써 개발될 가능성이 컸다. 또한, 진성 리더십은 분대 수준에서 리더에 대한 신뢰, 리더 지향 조직시민행동과 긍정적인 관계를 갖는 것으로 나타났다. 이러한 분석결과를 통해 본 연구는 기존 진성 리더십 연구들에서 밝혀지지 않은 진성 리더십의 선행요인을 확인하였으며, 군 조직에서 진성 리더십이 부하들의 리더에 대한 신뢰, 조직시민행동에 중요한 역할을 한다는 것을 밝혔다.