• 벤처창업연구
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• 제15권1호
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• pp.125-141
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• 2020

본 연구는 창업자의 전략적 지향성과 사회적 자본이 창업기업의 성과에 미치는 영향을 분석하였다. 전략적 지향성은 기업가적 지향성, 시장 지향성, 기술 지향성으로 구분하고 사회적 자본은 외부 네트워크의 지원과 창업팀에 대한 신뢰 및 응집력으로 정의하여 그 효과를 실증하였다. 또 사회적 자본이 전략적 지향성의 효과를 조절하는 조절효과가 있는지도 살펴보았다. 설립 5년 미만의 79개 스타트업을 대상으로한 실증분석에서, 기술 지향성만이 창업성과에 유의한 영향을 미치는 것으로 나타났다. 사회적 자본은 모두 창업성과에 유의한 효과를 미치는 것으로 나타났으며 그 조절효과는 부분적으로 검증되었다. 본 연구결과는 증거 중심의 스타트업 지원책을 수립하는데 공헌할 것으로 기대된다.

• 동력기계공학회지
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• 제10권2호
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• pp.22-28
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• 2006

Computer simulation of the air flow over an automotive vehicle is now becoming a routine process in automotive industry to assess the aerodynamic characteristics of a medium-size vehicle such as $C_d\;and\;C_1$ and aslo to investigate the possibility of improving aerodynamic performance of the vehicle as a preliminary design for the production line. Mainly due to its contribution in saving time and cost in the development of new cars, computer simulation of the air flow over a vehicle is usually done well before a production car is introduced to the market and in gaining more and more attention as powerful computer resources are getting readily available nowadays. To aerodynamically design a car is mainly related with reducing a drag coefficient of car. A well designed car usually has a $C_d$ value in the range of $0.3{\sim}0.4$. It is understandable that automotive industry is rushing to reduce a drag coefficient as reducing even a small fraction of the $C_d$ value can have an enormous overall impact on many areas. Actually, the present research model was able to achieve a $C_d$ value in the range of $0.3{\sim}0.36$ for flow velocities of $60km/h{\sim}100km/h$ by strategically removing the possible factor hazardous to lower $C_d$ value. Prediction of the medium-size vehicle aerodynamics using CFD was performed when an actual car model was in the development stage and three-dimensional modeling was also performed to optimize it as the best model in terms of the best aerodynamic performance.

• 인터넷정보학회논문지
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• 제21권2호
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• pp.19-26
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• 2020

This paper analyses the feasibility of using implantable antennas to detect and monitor tumors. We analyze this setting according to the wireless propagation loss and signal fading produced by human bodies and their environment in an indoor scenario. The study is based on the ITU-R propagation recommendations and prediction models for the planning of indoor radio communication systems and radio local area networks in the frequency range of 300 MHz to 100 GHz. We conduct primary estimations on 915 MHz and 2.4 GHz operating frequencies. The path loss presented in most short-range wireless implant devices does not take into account the human body as a channel itself, which causes additional losses to wireless designs. In this paper, we examine the propagation through the human body, including losses taken from bones, muscles, fat, and clothes, which results in a more accurate characterization and estimation of the channel. The results obtained from our simulation indicates a variation of the return loss of the spiral antenna when a tumor is located near the implant. This knowledge can be applied in medical detection, and monitoring of early tumors, by analyzing the electromagnetic field behavior of the implant. The tumor was modeled under CST Microwave Studio, using Wisconsin Diagnosis Breast Cancer Dataset. Features like the radius, texture, perimeter, area, and smoothness of the tumor are included along with their label data to determine whether the external shape has malignant or benign physiognomies. An explanation of the feasibility of the system deployment and technical recommendations to avoid interference is also described.

• Smart Structures and Systems
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• 제22권2호
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• pp.133-137
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• 2018

Increasing interest in prognostics and health management has heightened the need for wireless sensor networks (WSN) with efficient power sources. Piezoelectric energy harvesters using Pb(Zr,Ti)O3 (PZT) are one of the candidate power sources for WSNs as they efficiently convert mechanical vibration energy into electrical energy. These types of devices are resonated at a specific frequency, which has a significant impact on the amount of energy harvested, by external vibration. Hence, precise prediction of mechanical deformation including modal analysis of piezoelectric devices is crucial for estimating the energy generated under specific conditions. In this study, an experimental vibrational system capable of controlling a wide range of frequencies and accelerations was designed to generate mechanical vibration for piezoelectric energy harvesters. In conjunction with MATLAB, the system automatically finds the resonance frequency of harvesters. A small accelerometer and non-contact laser displacement sensor are employed to investigate the mechanical deformation of harvesters. Mechanical deformation under various frequencies and accelerations were investigated and analyzed based on data from two types of sensors. The results verify that the proposed system can be employed to carry out vibration experiments for piezoelectric harvesters and measurement of their mechanical deformation.

• 성인간호학회지
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• 제29권1호
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• pp.41-50
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• 2017

Purpose: The purpose of this study was to identify and compare the factors influencing attitude toward one's own aging among Korean middle-aged adults and the elderly. Methods: A cross sectional study was performed with a total sample of 70 middle-aged adults and 64 elderly reside in two metropolitan areas. Data were collected from August 2015 to November 2015 using the Perceived Health Status Scale, the Health Locus of Control Scale and the Attitude Toward own Aging (ATOA) Scale. The statistics used include percentage, t-test, Pearson's correlation coefficient, and multiple regression. Results: Mean age for each age group were about 52 and 76 years old for middle-aged adults and the elderly respectively. A considerable proportion of all participants reported a negative attitude toward aging. Perceived health status was the common factor influencing attitude toward one's own aging in both age groups. Middle-aged adults identified presence of chronic illness and internal health locus of control as important factors. In contrast, the elderly reported that education and others-dependent health locus of control such as powerful others had a significant impact on ATOA. Each regression model explained 31% and 55% of the total variance of ATOA among middle-aged adults and among the elderly. Conclusion: Both middle-aged adults and the elderly with low perceived health status are at risk of negative ATOA's. The type health locus of control need to be identified and utilized based on individuals' tendency to improve positive ATOA. That is, middle-aged adults might need reinforcement of their self-will whereas the elderly might need enhancement of social support and network of family and healthcare providers.

• 디지털융복합연구
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• 제18권5호
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• pp.473-484
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• 2020

패키지관광의 고객이 추구하는 동기와 제약을 검증하여 고객의 욕구에 부흥하는 콘텐츠 개발 및 패키지관광의 장점을 부각시켜 적극적인 홍보 등을 통하여 패키지관광의 활성화하는 방안을 제시하는 것이 연구 목적이다. 본 연구는 패키지관광을 경험 한 19세 이상의 성인 481명을 대상으로 SPSS 25.0을 이용하여 실증분석을 검증하였다. 연구 분석 결과는 다음과 같다. 첫째, 관광동기의 일상탈출, 외부활동, 서비스매력은 모두 태도에 긍정적인 영향관계가 검증되었다. 둘째, 관광제약의 내재적제약은 태도와의 관계에서 부정적인 영향을 가지는 것을 확인하였으나, 구조적제약은 유의적인 영향을 미치지 않은 것으로 규명되었다. 셋째, 태도는 만족도에 긍정적인 영향을 미치는 것으로 나타났다. 이러한 결과를 바탕으로 관광객이 패키지관광상품 참여시 중요하게 느끼는 요인이 무엇인지에 대하여 기술하였으며, 관광객이 요구하는 맞춤형 상품개발을 강구하는데 유용하게 활용되길 기대한다. 향후 패키지관광의 활성화에 필요한 현실성 있는 비교 연구로 확대할 필요가 있을 것이다.

• 수산해양교육연구
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• 제9권2호
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• pp.167-178
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• 1997

It has been expected not only for crew but also for passengers to realize a ship whose rolling and other motions are small as much as possible. Restricting our consideration to the roll reduction, the conventional roll stabilization system, fins or anti-rolling tanks hve been utiized as the actuator. Excessive motions would interfere with the recreational activities of passengers on a cruise ship. Often more than half of the load of a containership is stowed above deck where it is subjected to large acclerations due to rolling. In some situations this may cause some internal damage to the contents of the containers; in more severe situations failure of the lashing can occur and containers may be lost over-board. Underdeck cargo in ordinary cargo ships and bulk commodities in colliers, ore ships and grain ships can shift if the motions become too severe. The purpose of this study is to concentrate on the additions. either internal or external to the hull, that reduce or otherwise improve the motion responses of the hull. It is assumed that the additions are such that their benefit to the motions of the ship outweights any impact on the ability of the ship to perform its assigned task. It is particularly challenging to obtain large improvements in the motion characteristics of existing ships that are being rebuilt or modified for some task not anticipated in their original design. Further the authors will statistically analyze the influence of ruder-roll-yaw coupling motion in the case of application of this advanced control method to various kinds of ship.

• 한국재난정보학회 논문집
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• 제12권4호
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• pp.329-341
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• 2016

신종 인플루엔자 유행과 같은 사회적 위기는 기업을 비롯한 다양한 조직에 영향을 미치게 되고 이에 대한 활동과 결과는 사회적 위기와 조직의 특성에 따라 다를 것이다. 사회적 위기에 대한 조직의 단기적인 대응을 이해하는데 ser-M 모델을 이용한 메카니즘 기반 관점은 현재까지 사용되지 않았으나, 본 연구를 통해 ser-M 모델을 활용한 연구가 단기간 특정 사건을 대상으로도 가능함을 보이고, 위기나 재난과 관련된 접근 방법의 하나로 활용할 수 있음을 보고자 하였다. 본 연구에서는 신종 인플루엔자를 직접 대응하는 의료기관에서 사회적 위기로서 신종 인플루엔자에 어떻게 대처하였는지를 알아봄과 동시에 그 활동과 운영의 변화를 최신의 ser-M 모델을 적용하여 보고자 하였다. 본 사례로 볼 때 신종 플루 유행과 같은 외부 요인으로 인한 기업의 위기 상황에서 효율적 대응을 위한 준비와 그 과정에 대한 경영학적 접근, 특히 ser-M 모델을 적용한 기업 측면의 구체적 사례 연구가 부족한 데 대한 초기단계 연구로서 의의가 있을 것이며, 메커니즘 이론이 장기적 경영 전략 뿐 아니라 단기적 외부 상황 변화에 따른 기업의 영향을 분석하는 데에도 사용 가능할 것으로 사료된다.

• 한국도로학회논문집
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• 제14권5호
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• pp.93-99
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• 2012

PURPOSES: The purpose of this study is to compare the alkali-silica reactivity for mortar bar and concrete prism specimens using crushed aggregates of 5 types in Korea. And the alkali-silica reactivity for those aggregates are measured by chemical test method. METHODS: The alkali-silica reactivity for those aggregates was measured by chemical test method of KS F 2545, mortar-bar test of KS F 2546, accelerated mortar-bar test method of ASTM C 1260 and concrete prism test method of ASTM C 1293, relatively. RESULTS: The alkali-silica reactivity for those aggregates was verified by chemical test of KS F 2546 and accelerated mortar-bar test of ASTM C 1260. However, it was not by mortar-bar test of KS F 2546 and concrete prism test of ASTM C 1293. CONCLUSIONS: The above results showed that relationship among the four test methods were very low. The results from 3 types of test methods using cement-aggregate combinations appeared to be different. Because the environmental conditions of test methods for measuring the alkali-silica reactivity such as equivalent alkali content(external source), humidity, temperature, and times were different though the aggregates were same. Moreover, alkali-silica reactivity showed the biggest impact when alkalis were supplied form outside and exposed to environmental conditions. The accelerated mortar-bar test method seems to be most appropriate test method for concrete structures exposed to alkali environment.

• 융합보안논문지
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• 제13권3호
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• pp.71-77
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• 2013

우리나라는 보안산업 현장에 적용할 적합한 비즈모델 분석 방법론을 발견하기 어렵고 단편적 이론은 존재하지만 종합적 분석 방법론은 희소한 실정이다. 정보보안 기업 비즈모델 분석은 외부요인과 내부요인에 관해 수집된 정보를 통합하고 포괄적으로 분석하는 정보시스템 개발이 요구된다. 비즈모델 분석을 위한 정보시스템의 소프트웨어 아키텍처는 시스템 설계의 초기 결정사항으로서 초기 결정은 설계, 개발, 테스트, 유지보수에 지속적인 영향을 미친다. 정보보안 비즈모델 분석시 BMO에 기반한 소프트웨어 아키텍쳐는 정보시스템의 목적이나 사명 수행을 지원 한다. 정보보안 비즈모델 분석을 위한 정보시스템은 여러 이해관계자들이 사명과 환경을 결정하며 그 결과가 아키텍처 기술서로 문서화 되어야 활용될 수 있다. 아키텍처 기술서는 소프트웨어 아키텍처를 결정한 근거를 제시하기 때문이다.