• 기술혁신연구
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• 제6권2호
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• pp.101-121
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• 1998

Recent entrepreneurship studies emphasize the importance of entrepreneurial activities of entrepreneurs. This study focuses entrepreneurial behaviors, especially entrepreneurial networking activities of Korean high-tech ventures. Networking activities can utilize external resources which are critical to success, with less resource commitment. This study examines the relationship between characteristics of entrepreneurial networking and performance, and analyses influencing factors of entrepreneurial networking activities. Based on the data from 55 new high-tech ventures in Korea, hypotheses that the characteristics of entrepreneurial networking are related to the performance of new high-tech ventures are tested using regression analysis and t-test. Major findings of this study are as follows: (1) entrepreneurial networking are related to the performance of new high-tech ventures, (2) significant differences are found in the characteristics of entrepreneurial networking between high- and low-performance firms, (3) characteristics of entrepreneurs and firm' technological capabilities are related to the degree of entrepreneurial networking activities. Finally, managerial and policy implications of the study are presented and future research directions are also suggested.

• 한국수학교육학회지시리즈A:수학교육
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• 제59권4호
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• pp.295-312
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• 2020

본 연구는 중등학교 수학교사의 평가에 대한 인식을 조사하고 비교하기 위하여 진행되었다. 이를 위해 인천지역에 근무하는 중학교 188명, 고등학교 125명의 수학교사로부터 평가에 관한 6가지 영역과 과정 중심 평가에 대한 일반적인 인식에 대하여 설문조사를 실시하였다. 연구 자료는 중요도-수행도 분석기법(IPA)을 사용하여 학교급별, 경력별, 학교규모별로 비교 분석하였다. 주요 연구 결과로 대부분의 영역에서 중학교 수학교사들이 고등학교에 비해 중요도와 수행도 모두 높게 나타났다. 경력별로는 경력이 높을수록 높은 중요도-높은 수행도, 낮은 중요도-낮은 수행도가 많이 나타나고. 학교규모가 클수록 낮은 중요도-높은 수행도에 다양한 의견이 나타났다.

• 복합신소재구조학회 논문집
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• 제4권3호
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• pp.22-29
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• 2013

In recent years, the construction of high-rise buildings are promoted. According to these, there are many needs about new technologies to strengthen the building performance and high-strength steel is regarded as one of these for promoting building performance. In Korea, high-strength steels which stress are over 600MPa are on market and in aborad, super high-strength steels over 1000MPa are developing and they expected to promote the building performance. But there are still doubts about applying high-strength steel members because of size effect and worry of brittle fracture. In this reports, we propose results of performance and analysis tests for use with general steel. We propose the characteristic of high-strength steels first and next the results of performance test to show they satisfy the performance that designers expect. And last, we compare the results of test and analysis for acquire the alanysis reliability in non-linear analysis with high-strength steels.

• 노동경제논집
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• 제32권2호
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• pp.27-60
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• 2009

"사업체패널조사" 자료에 근거하여 노동자참여적 고성과작업관행들이 경영성과를 높이고 노동자들의 임금을 높이는 쪽으로 보상도 증가시켜 왔는지 여부를 분석한 결과 (1) 기업의 경영성과에 대체로 긍정적인 효과를 주었으나 몇몇을 제외하고는 그 효과가 뚜렷하지 않았으며, (2) 임금상승 효과는 좀 더 뚜렷하게 나타났다. 노동조합이 조직된 사업체는 고성과작업관행들의 임금효과가 좀 더 강화 된다는 점이 발견되는데, 이는 노동조합이 없는 기업들의 경우 고성과작업관행들의 지속을 위해서는 그 도입 설계 단계에서부터 노동자대표들의 참여를 유도하고 그 성과가 노동자들에게도 적절하게 배분될 수 있도록 특별한 노력을 경주할 필요가 있다는 함의를 제시하는 것이다.

• 한국철도학회논문집
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• 제6권2호
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• pp.100-107
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• 2003

This paper presents development of train performance simulation(TPS) program to analyze traction performance, braking performance and energy consumption for Korea high speed railway system. The conventional TPS program have some inconveniences such as DOS-based platform, user interface and limited function. The simulation technique model using scenario menu, various analysis function and object-oriented design/programming is presented. This simulation result have been compared with Alstom's for the Seoul-Pusan High Speed Rail Project.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.35-36
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• 2016

Recently, with the increasing demand of high performance of concrete, the mix design of concrete mixture has became low water-to-binder ratio with high binder content. To compensate these trend of mix design, high range water reducer, or superplascizier has been invented to achieve high flowable concrete. Although this superplasticizer provides favorable workability based on its dispersing action on the components of concrete mixture, it has an limitation of decreasing viscosity of the mixture, and thus it is difficult to secure sufficient workability for high performance concrete mixtures with high binder content. To improve the workability of concrete with high viscosity, recently, low-viscosity type superplasticizer was introduced, and in this research, a fundamental properties of low-viscosity type superplasticizer is evaluated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.461-464
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• 2006

Recently, as structures become bigger and higher, it is needed that high strength, high flow and high durability concrete. Demanding of High performance concrete that equality is maintained without material separation while flow, strength is increased by using low W/C rate and admixture, carbonation does not occur because of dense filling and has high durability is increasing rapidly. Because this high performance concrete is superior to general concrete in workability and durability, it is widely used in many construction and engineering works fields. However, it is reported that when it was exposed in fire, violent explosive spalling would be happened. Therefore, the purpose of this study evaluates explosive spalling properties of fire damaged high performance concrete according to the heating time.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.94-95
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• 2020

This paper introduces the mix design and performance evaluation of Ultra-High Performance Concrete (UHPC). The concrete mixture is designed to achieve a densely compacted cementitious matrix via the modified Andreasen & Andersen particle packing model. The compressive strengths of UHPC designed by this method reached 154MPa. The relationship between packing theory and compressive strength of UHPC is discussed in this paper.

• Journal of Communications and Networks
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• 제17권4호
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• pp.370-383
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• 2015

Effective link quality estimation is a vital issue for reliable routing in wireless networks. This paper studies the performance of expected transmission count (ETX) under different traffic loads. Although ETX shows good performance under light load, its performance gets significantly worse when the traffic load is high. A broadcast packet storm due to new route discoveries severely affects the link ETX values under high traffic load, which makes it difficult to find a good path. This paper presents the design and implementation of a variation of ETX called high load - ETX (HETX), which reduces the impact of route request broadcast packets to link metric values under high load. We also propose a reliable routing protocol using link quality metrics, which is called link quality distance vector (LQDV). We conducted the evaluation of the performance of three metrics - HETX, ETX and minimum hop-count. The simulation results show that HETX improves the average route throughput by up to 25% over ETX under high traffic load. Minimum hop-count has poor performance compared with both HETX and ETX at all of the different traffic loads. Under light load, HETX and ETX show the same performance.

• Computers and Concrete
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• 제33권3호
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• pp.309-324
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• 2024

Internal curing, a widely used method for mitigating early-age shrinkage in concrete, also offers notable advantages for concrete durability. This paper explores the potential of internal curing by partial replacement of sand with fine lightweight aggregate for enhancing the behavior of high-performance concrete at elevated temperatures. Such a technique may prove economical and safe for the construction of skyscrapers, where explosive spalling of high-performance concrete in fire is a potential hazard. To reach this aim, the physico-mechanical features of internally cured high-strength concrete specimens, including mass loss, compressive strength, strain at peak stress, modulus of elasticity, stress-strain curve, toughness, and flexural strength, were investigated under different temperature exposures; and to predict some of these mechanical properties, a number of equations were proposed. Based on the experimental results, an advanced stress-strain model was proposed for internally cured high-performance concrete at different temperature levels, the results of which agreed well with the test data. It was observed that the replacement of 10% of sand with pre-wetted fine lightweight expanded clay aggregate (LECA) not only did not reduce the compressive strength at ambient temperature, but also prevented explosive spalling and could retain 20% of its ambient compressive strength after heating up to 800℃. It was then concluded that internal curing is an excellent method to enhance the performance of high-strength concrete at elevated temperatures.