• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.301-304
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• 2006

본 논문에서는 종전의 고정식 카메라 방식과 다르게 영상내에 두개의 라인을 적용함으로서 차량의 속도와 차량의 대수를 측정할 수 있는 방법을 제안하였다. 제안된 방법은 50km/h, 80km/h, 90km/h의 속도로 달리는 차량을 녹화하여 시작점과 도착점의 시간을 추출하고, 추출된 시간차와 거리에 의해서 47.57km/h, 81.20km/h, 90.00km/h속도를 계산하였으며 매우 양호하게 일치함을 보였다.

• 분석과학
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• 제26권3호
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• pp.199-204
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• 2013

본 연구에서는 음주 후 시간경과에 따른 혈중알코올농도 변화의 재현성을 실험하였다. 5명의 한국인 자원자에게 22%(v/v) 소주 한병(ethyl alcohol로 환산했을 경우 55.5 g)을 30분 안에 나눠 마시게 하는 실험을 5회 반복하였다. 자원자들에게는 안주로 회와 탕수육을 교대로 제공하였다. 알코올 섭취량과 섭취시간을 일정하게 유지했음에도 불구하고 혈중알코올농도가 최고에 이르는 시간과 그 때의 농도 및 시간경과에 따른 혈중알코올농도의 감소율은 사람에 따라 큰 차이를 보였다. 또한 안주에 따라서도 시간 변화에 따른 혈중알코올농도 변화곡선이 달라지는 것을 확인할 수 있었다. 동일인에게 5회에 걸쳐 각기 다른 날 동일한 조건으로 음주하게 한 후 혈중알코올농도 변화곡선을 관찰한 결과, 시간경과에 따른 혈중알코올농도변화는 재현성이 없이 나타나는 것을 확인하였다. 또한 특정 시간대의 혈중알코올농도를 정확하게 역추정하는 것은 불가능하다는 것을 알 수 있었다.

• 한국어병학회지
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• 제24권2호
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• pp.53-64
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• 2011

Megalocytivirus 감염 시 나타나는 임상적 증상의 정량적인 분석을 위하여, 돌돔에서 분리된 megalocytivirus IVS-1을 돌돔성어와 치어에 인위 감염시켰다. 그 결과 spleen index가 각각 $4.49{\pm}1.13$와 $4.85{\pm}1.06$로 나타 났으며, 이것은 정상배에 비해 3배 이상 증가한 값이었다. 폐사율은 돌돔성어와 치어에서 모두 100% 폐사한 반면 참돔치어는 30일이 지나도 60%의 폐사만 나타나 돌돔폐사율에 비해 낮은 폐사율을 나타냈다. 또한 IVS-1을 감염시킨 빈사상태의 참돔치어는 spleen index가 동일 크기의 돌돔치어 보다 낮은 $1.47{\pm}0.87$을 보였다. Real-time PCR을 이용하여 감염의 진행에 따른 바이러스 농도를 측정한 결과, 돌돔 치어와 성어의 감염 조직 내 바이러스 최고 농도는 각각 $2.03{\times}10^7$ copies/mg과 $2.40{\times}10^7$ copies/mg으로 비슷하였으나 돌돔성어에서 먼저 최고치에 도달하였다. 더구나 비장의 비정형비대세포의 수 역시 돌돔치어의 경우 지속적으로 증가한 반면 돌돔성어의 경우 최고치에 도달 후 오히려 감소히는 경향을 보였다. 본 연구에서는 megalocytivirus 감염 시 조직의 형태적 변화와 조직 내의 바이러스 농도와 같은 임상적인 증상을 정량적인 분석을 통해 나타내었고 이러한 정량적인 수치와 megalocytivirus 감염의 진행 정도와의 상관관계에 대해 조사하였다.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.94-101
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• 2009

This study which is the fundamental work to investigate the property of urban climate compared the property of thermal environment in the downtown location and the outskirt site based on the field observation in the summer. We analysed thermal environment in the downtown location mainly by distributional characteristics during day and night with changes and correlation analysis of the air temperature, the globe temperature and the surface temperature through the simultaneous observation of the property of thermal environment at two places in real time. The summary of finding in this study is as follows. (1)It is observed on the day chosen by sample that diurnal air temperature range in the downtown location is $22.3{\sim}34.9^{\circ}C$, and diurnal air temperature range in the Outskirt site is $20.0{\sim}34.3^{\circ}C$, so, we found that the diurnal air temperature range in the outskirt site is $1.7^{\circ}C$ higher than in the downtown location. (2)In comparison of the globe temperature after sunset, we found the change of more sudden temperature drops in the outskirt site than in the downtown location. (3)It is observed on the days chosen by sample that the average of globe temperature range is $1.1^{\circ}C$, the average of surface temperature range is $1.0^{\circ}C$, and air temperature range is $2.0^{\circ}C$, thus, the we found that the average of air temperature is $1.0^{\circ}C$ higher than globe temperature and the surface temperature. (4)After the consideration of air temperature and globe temperature distribution, the highest temperature reaching time of globe temperature is one hour earlier than air temperature in the downtown location, on the other hand, although the highest temperature reaching time of globe temperature in the outskirt sites is one hour later than in the downtown location, the timelag found in the downtown location was not found in the outskirt site.

• 한국환경과학회지
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• 제6권3호
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• pp.267-276
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• 1997

It has been studded that combustion and the production of air pollution of anthracite - bituminous coal blend In a fluidized bed coal combustor, The objects of thIns study were to investigate mixing characteristics of the particles as well as the combustibility of the low grade domestic anthracite coal and Imported h19h calorific bltununous coal in the fluidized bed coal combustor. They were used as coal samples ; the domestic low grade anthracite coal with heating value of 2,010kca1/kg and the Imported high grade bituminous coal with beating value of 6,520kca1/kg. Also, the effects of air flow rate and anthracite fraction on the reaching time of steady state condition have been studied. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 300sc1h which was the fastest. It has been found that $O^2$ and $CO^2$ concentration were reached steady state at about 100 minute. It has been found that $O^2$ concentration decreased and $CO^2$ concentration increased as the height of fluidlzed bed Increased. It was found that splash zone was mainly located from 25cm to 35cm above distributor. Also, as anthracite traction Increased, the mass of elutrlatlon particles Increased, and $CO^2$ concentration decreased. As gk flow rate Increased,$O^2$ concentration decreased and $CO^2$ concentration increased. Regardless of anthracite fraction and flow rate, the uncombustible weight percentage according to average diameter of elutriation particles were approldmately high In the case of One Particles. As anthracite traction and k now rate Increased, elutriation ratio Increased. As anthracite fraction was increased, exit combustible content over feeding combustible content was Increased. Regardless of anthracite fraction, size distribution of Ued material from discharge was almost constant. Over bed temperature 85$0^{\circ}C$ and excess air 20% , the difference of combution efficiencies were little. It is estimate that the combustion condition In anthracite-bituminous coal blend combustion is suitable at the velocity 0.3m/s, bed temperature 85$0^{\circ}C$, the excess air 20%.

• 제어로봇시스템학회논문지
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• 제5권8호
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• pp.889-897
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• 1999

This paper deals with a problem searching a target transfer function to meet the time-domain specifications for feedback system with given plant transfer function. For the Type I system, we first define three forms of transient response to unit step input, which are named by F, M, S-type. These are charaacterized as follows ; F-type has fast initial response and slow approach to the steady sate after reaching at 90% of the steady state value, S-type has slow initial response but fast approach to the steady state, and M-type is denoted by highly smooth response between F-type and S-type. Three prototypes corresponding to each form are proposed, time. For the order $n{\geq}4$, after determining admissible root structures of target characteristic polynomials empirically and expressing such polynomial coefficients by using special parameters ${\gamma}_i$ and $\epsilon$, the optimal prototypes that minimize the integral of the squared of the modified errors(ISME) have been obtained. Since the step responses of these prototypes have almost same wave forms irrespective to the order, the desired settling time or the rise time can be converted into the equibalent time constant $\tau$ and thus it is easy to obtain a target transfer function. It is shown through a design example that the present prototype is very useful for meeting the time-domain specifications and has been compared with different methods with a viewpoint of pertinence.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2002년도 학술대회지
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• pp.316-322
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• 2002

근로시간이 단축될 경우 건설산업은 타산업과는 달리 일회성, 옥외성, 계절성 등의 특성으로 인하여 근로시간 단축으로 인한 파급효과를 단순히 작업의 총량개념으로만 접근하여 분석하기에는 어려움이 있다. 법정 근로시간 단축의 영향을 보다 정확하게 예측하기 위해서는 예상되는 비용상승 효과가 실제 건설공사 생산구조에 어떻게 받아들여질 것인가에 대한 조사와 분석이 필수적이다. 이를 위해 건설현장의 근로시간과 근로패턴에 관한 문헌조사와 일본 건설산업의 근로시간 단축 사례 조사를 수행하였으며, 결과적으로 근로시간 단축으로 인한 현장의 근로패턴 변화를 분석${\cdot}$ 예측하였다. 근로 패턴 변화는 실제 생산활동에 참여하는 현장근로자를 대상으로 년 단위 현행 모델과 근로시간 단축 후의 예측 모델을 구축하여 비교${\cdot}$분석하였으며, 현장관리 측면에서의 대처방안을 제시하였다.

• 아태비즈니스연구
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• 제12권1호
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• pp.151-163
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• 2021

Purpose - The break-even point refers to the point where total profit and total cost coincide, and from this point on, the entrepreneur's decision-making takes a different route. Strategic decisions can be made for more efficient operation and eventually for more likelihood for growth and sustainability if a startup figures out when it recoups the investment and switches to a net profit. Design/methodology/approach - 748 creativity and skill-based sole proprietors in manufacturing industry were examined to demonstrate the effect of the entrepreneur's entrepreneurial experience and education level, the business launch preparation time, or the self-financing on the achievement of break-even point. Findings - While the business launch preparation time lowered the likelihood of reaching a break-even point, self-financing increased the likelihood. As a result of further analysis by subdividing into subgroups according to skill level, only the business launch preparation time was statistically significant in the highly skilled industries. In the low skilled industries, in addition to the business launch preparation time, the CEO's education level and the self-financing were statistically significant. Research implications or Originality - The longer the business launch preparation time, the higher the start-up cost, which increases the burden of initial cost recovery, and the agile response to market changes is thereby delayed, resulting in the business idea losing its appeal. Self-financing not only provides stability and strong motivation for the business operation but also promotes careful spending which contributes to the achievement of break-even point. In particular, it is found that practical experience is more useful than theoretical knowledge in low skilled industries. Due to the limitation of secondary data based on the recollection, the time required to reach a break-even point, percentage of financing sources, etc. may include cognitive errors. In addition, variables are not included that explain the characteristics of creativity and skill-based sole proprietorship, so it is necessary to exercise caution with the actual application.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.227-230
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• 1997

In this paper, robot navigation experiments with a new navigation algorithm are carried out in real environments. The authors already proposed a reactive navigation algorithm for mobile robots using optimal via-point selection method. At each sampling time, a number of via-point candidates is constructed with various candidates of heading angles and velocities. The robot detects surrounding obstacles, and the proposed algorithm utilizes fuzzy multi-attribute decision making in selecting the optimal via-point the robot would proceed at next step. Fuzzy decision making allows the robot to choose the most qualified via-point even when the two navigation goals-obstacle avoidance and target point reaching-conflict each other. The experimental result shows the successful navigation can be achieved with the proposed navigation algorithm for real environments.

• 융복합기술연구소 논문집
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• 제10권1호
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• pp.41-45
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• 2020

This paper presents the effects of a virtual mass on the stability boundary of a virtual spring in the haptic system with first-order-hold. The virtual rigid body is modeled as a virtual spring and a virtual mass. When first-order-hold is applied, we analyze the stability boundary of the virtual spring through the simulation according to the virtual mass and the sampling time. As the virtual mass increases, the stability boundary of the virtual spring gradually increases and then decreases after reaching the maximum value. The results are compared with the stability boundary in the haptic system with zero-order-hold. When a virtual mass is small, the stability boundary of a virtual spring in the system with first-order-hold is larger than that in the system with zero-order-hold.