• 한국농공학회논문집
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• 제53권6호
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• pp.153-163
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• 2011

This research describe improved algorithm that is able to decide terminal criterion of Evolutionary Structural Optimization (ESO), reducing load of calculation to search load path of concrete beam, and apply to agricultural facilities. The ESO method is that make to discrete structure, structural analyze each element stress through FEM. And repeat generation with next material condition to become for most suitable composing. Individual element introduces concept of zero stiffness, but zero stiffness decisions are gone to direction of exclusion. In this stduy, improve algorithm to be convergence by 'Rule of Alive or Die' in arrival because is most suitable. Also, existing terminal criterion lack consistency because that used depend on experience of researcher. This research procedure is fellowed. First, all modulus of elasticity assume a half of elasticity modulus of material, Second, structural analysis by FEM, Third, apply to the remove ratio and restoration ratio for the 'rule of alive or die'. Forth, reconstruct the element and material conditions. And repeat the first to forth process. The terminal time of evolutional procedure is the all elastic modulus of element changed to blank value or elasticity modulus value of original. Therefore, in this study, consist the algorithm for programming, and apply to the agricultural facilities with concrete.

• International Journal of Aeronautical and Space Sciences
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• 제15권3호
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• pp.281-292
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• 2014

We propose a novel cooperative guidance law design method based on the finite time disturbance observer (FTDO) for multiple near space interceptors (NSIs) with impact time control. Initially, we construct a cooperative guidance model with head pursuit, and employ the FTDO to estimate the system disturbance caused by target maneuvering. We subsequently separate the cooperative guidance process into two stages, and develop the normal acceleration command based on the super-twisting algorithm (STA) and disturbance estimated value, to ensure the convergence of the relative distance. Then, we also design the acceleration command along the line-of-sight (LOS), based on the nonsingular fast terminal sliding mode (NFTSM) control, to ensure that all the NSIs simultaneously hit the target. Furthermore, we prove the stability of the closed-loop guidance system, based on the Lyapunov theory. Finally, our simulation results of a three-to-one interception scenario show that the proposed cooperative guidance scheme makes all the NSIs hit the target at the same time.

• 한국도로학회논문집
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• 제19권2호
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• pp.143-152
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• 2017

PURPOSES : This study intends to estimate the tangible benefits derived from the integration of operations of an Express Intercity Bus Terminal and a Highway Service Area. METHODS: For the study, a highway service area was chosen to function as a bus terminal, integrating its services with that of a nearby bus terminal plagued by operating losses. The exercise also helped improve mobility owing to the introduction of local buses between the terminals and utilization of the existing infrastructure such as rest areas. Thus, a terminal that was not being utilized for its intended functionality was integrated with an existing facility to improve the utilization of both and subsequently aid local development. The impact of the exercise was then measured by evaluating the variation in utilization efficiency, operating costs, travel time between two regions (Seoul-Jeomchon and Seoul-Geumsan), and the social costs before and after the integration of the two facilities. RESULTS :The impact of the integration was an increase in utilization efficiency, a decrease in operating cost, a decrease in travel time, and a decrease in social cost in both the regions. The benefits of improved utilization and cost saving can be passed on to the citizens in the form of discounts. A local power generation facility will eventually replace the bus terminal, which can revitalize the local economy. CONCLUSIONS :The integration of the highway service area with the bus terminal is expected to have a win-win effect on the passengers as well as the operators. The study also proposes a sustainable strategic plan for existing terminals and rest areas to implement a method to compete with KTX transportation.

• 전기전자학회논문지
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• 제25권1호
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• pp.201-205
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• 2021

본 논문에서는 push-pull 감지 회로 구조로 인해 load transient 특성을 개선시킨 LDO를 제안하였다. LDO 레귤레이터 패스 트랜지스터의 입력단과 내부 오차증폭기의 출력단 사이에 제안된 push-pull 감지 회로 구조로 인한 전압 델타 값의 응답 특성을 개선시켜 종래의 LDO 레귤레이터보다 load transient 특성에서 우수한 효과를 가진다. 기존의 LDO 레귤레이터보다 rising time에서는 약 244 ns, falling time에서는 약 90 ns 만큼의 향상된 응답속도를 가진다. 제안된 회로는 Cadence사의 Spectre, Virtuoso 시뮬레이션 tool을 사용하여 samsung 0.13um 공정으로 특성 및 결과를 시뮬레이션 하였다.

• 한국항해항만학회지
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• 제28권1호
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• pp.69-74
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• 2004

Container Freight Station(CFS)은 터미널의 내부 또는 외부에 배치되어 여러 화주의 소량(Less than Container Load ; LCL) 화물을 컨테이너화시키거나, 수입된 컨테이너에서 내품을 인출하여 여러 화주에게 분산시키는 기능을 담당하고 있다. 하지만 CFS가 터미널 내부에 배치될 경우에는 LCL화물을 운송하기 위한 일반차량의 운행이 증가하여 터미널 주변의 교통 혼잡, 높은 사회 비용 및 물류비용의 발생, 장치장의 장치 여건 악화 등과 같은 문제를 초래한다. 본 연구는 현재 개발 중인 부산신항만을 대상으로 CFS를 각 터미널 내부에 개별적으로 배치하는 경우와 북측 컨테이너 부두 배후지에 거점화할 경우에 대해 총 비용 관점(사회적 비용과 물류비용)에서 경제성을 평가하는 것을 그 목적으로 한다.

• 대한수학회보
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• 제53권3호
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• pp.793-819
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• 2016

In this paper, we establish the existence and uniqueness of the solution for a class of reflected backward stochastic differential equations with time delayed generator (RBSDEs with time delayed generator, in short) in the case when the terminal value and the obstacle process are $L^p$-integrable with p ${\in}$]1, 2[ for a sufficiently small Lipschitz constant of the generator and the time horizon T.

• 대한치과보철학회지
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• 제45권2호
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• pp.250-262
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• 2007

Statement of problem: It was reported high success rate of implant-supported fixed prostheses using with $5{\sim}6$ implants on anterior mandible. Recently, immediate loading protocol was focused to overcome disadvantages of classic 2-stage delayed loading protocol. Purpose: This clinical study was to evaluate stability changes with time of immediately loaded and delayed loaded implants in edentulous mandible and to compare stability changes with time according to implantation sites. Materials and methods: Five or six implants were placed on anterior mandible depending on the arch shape. The immediately loading group was consisted of 8 patients received their prostheses within $24{\sim}48$ hours after implantation. The delayed loading group was consisted of 8 patients received their definitive prostheses following classical prosthetic procedures after a healing period of 3 months. All patients were recalled every 6 months for check-up. The evaluations of radiographic examination, ISQ value measurement and recording of complication were done. To evaluate marginal bone level, intraoral periapical radiographs were taken with long cone paralleling technique. At every evaluation recall, all prostheses were removed and ISQ values were measured with OsstellTM on individual implants. Results: 1. None of implants was failed. All implants showed stable marginal bone levels and ISQ values. 2. Marginal bone level changes with time showed statistically significant difference between immediately loading group and delayed loading group (P<0.001). 3. ISQ value changes with time did not show statistically significant difference between immediately loading group and delayed loading group (P=0.079). ISQ value decreased with time in both groups, however, all implants showed stable ISQ value at 30 months-recall evaluation. 4. Marginal bone level changes with time did not show statistically significant differences among implantation sites (P=0.604). 5. ISQ value changes with time showed statistically significant differences among implantation sites (P=0.047). ISQ values of most posterior implants decreased with time comparing to other implants. Conclusion: Although the marginal bone level of the terminal abutment didn't different with the other implants, ISQ value of the terminal abutment was lower than that of the other implants. Therefore, further clinical evaluation would be needed in this point of view.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.195-198
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• 1997

This paper proposes the effective compensation method of the rotor time constant of induction motor. An indirect vector control method is highly dependent on the motor parameters. To solve the problem of performance degradation due to parameter variation in an indirect vector control of induction motor, we compensate the rotor time constant by current error feedback. The proposed method is a simple on-line rotor time constant compensation method using the information from terminal voltages and currents. As the current error, difference between current command and estimated current, approaches to zero, the value of rotor time constant in an indirect vector controller follows the real value of induction motor. This scheme is valid transient region as well as steady state region regardless of low or high speed. This method is verified by computer simulation. For this, we constructed the simulation model of induction motor, indirect vector controller and current regulated PWM (CRPWM) voltage source inverter (VSI) using SIMULINK in MATLAB.

• 산업경영시스템학회지
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• 제28권3호
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• pp.75-86
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• 2005

To investigate the fatigue characteristic of upper limbs, this study analyzed RMS(root mean square) and MPF(mean power frequency) value between initial and terminal stages of each experiment condition. And the effect of intermittent endurance time was evaluated using the Borg's CR10 value that was measured for the parts of upper limb. According to the results of ANOVA on RMS value, there were significant difference on the %MVC about push, pull, and down force exertion. Particularly the ANOVA of up force exertion was significant difference on shoulder flexion, elbow flexion and rest time as well as %MVC. The results of ANOVA for MPF value were significant difference on the %MVC in regard of the push and up force exertion. In case of up force exertion, MPF value tended to shift low frequency at all of the experiment conditions. According to the analysis of duty cycle, RMS value considerably increased over 50% duty cycle and as the %MVC increased, the duty cycle affected the increase of RMS value. MPF value for up and down force exertion decreased at 33%, 50% and 67% duty cycle for all of %MVC. Borg CR10 value of hand and forearm were below the 3-point to the 40% of endurance time at 30%MVC and to the 20% of endurance time at 50%MVC with the exception of up force exertion. But Borg CR10 values of upper arm and shoulder at up force exertion were more than 3-point to the 20% of endurance time at 30%MVC and in the start point of endurance time at 50%MVC.

• 대한방사선기술학회지:방사선기술과학
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• 제36권1호
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• pp.19-24
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• 2013

요골 말단 부위의 측정은 한국 사람들이 주로 오른손을 자주 사용한다는 근거로 왼쪽 요골 말단 부위를 주로 측정하는데 이로 인한 잘못된 결과가 나오기도 한다. 본 연구에서는 이러한 측정부위 오차가 가지는 상관관계를 알아보고 잘못된 측정 오차를 줄이고자 한다. 2012년 3월부터 일정기간 정형외과를 방문한 성인 50대 이상 남녀 환자를 대상으로 전완부의 단순촬영 자세와 같이 중립위를 기준으로 왼쪽 원위요골말단부위를 포함한 오른쪽 원위요골말단부위도 함께 측정하여 양쪽 T-score를 통해 비교 분석하였다. 그 결과 왼쪽 손목 수치가 더 낮은 그룹은 전체 75명 중 45명으로 약 60%를 차지하였고 반면 오른쪽 손목 수치가 더 낮은 그룹은 전체 75명 중 30명으로 약 40%를 차지하였다.