• 한국컴퓨터정보학회논문지
• /
• 제25권9호
• /
• pp.63-69
• /
• 2020

이미지-이미지 변환은 입력 이미지를 통해서 목적 이미지를 만들어내는 기술로 최근 비지도 학습 구조인 GAN을 활용하여 더 실제와 같은 이미지를 만들어내는 높은 성과를 보였다. 이에 따라 GAN을 활용한 이미지-이미지 변환 연구는 다양하게 진행되고 있다. 이때 일반적으로 이미지-이미지 변환은 하나의 속성 변환을 목표한다. 그러나 실제 생활에서 사용되고 얻을 수 있는 자료들은 한 가지 특징으로 설명하기 힘든 다양한 특징으로 이루어진다. 그래서 다양한 속성을 활용하기 위하여 속성별로 이미지 생성 과정을 나누어 학습할 수 있도록 하는 다중 속성 변화를 목표로 한다면 더 이미지-이미지 변환의 역할을 잘 수행할 수 있을 것이다. 본 논문에서는 GAN을 활용한 이미지-이미지 변환 구조 중 높은 성과를 보인 CycleGAN을 활용해 이중 속성 변환 구조인 Multi CycleGAN을 제안한다. 이 구조는 입력 도메인을 두 가지의 속성에 대하여 학습하기 위하여 3개의 도메인이 양방향 학습을 진행하는 이중 변환 구조를 구현하였다. 새로운 구조를 통해 생성된 이미지와 기존 이미지-이미지 변환 구조들을 통해 생성된 이미지를 비교할 수 있도록 실험을 진행하였다. 실험 결과 새로운 구조를 통한 이미지는 입력 도메인의 속성을 유지하며 목표한 속성이 적용되는 높은 성능을 보였다. 이 구조를 활용한다면 앞으로 더 다양한 이미지를 생성하는 일이 가능지기 때문에 더 다양한 분야에서의 이미지 생성의 활용을 기대할 수 있다.

• 한국주조공학회지
• /
• 제9권6호
• /
• pp.463-473
• /
• 1989

This study is aimed to investigate the effect of cyclic heat treatment which is special heat treatment on the strength and toughness in Multi-phase(Ferrite-Bainite-Martensite) Ductile cast Irons. Spceimens were austenitized at eutectoid transformation temperature range(${\alpha}+{\gamma}$) for 30min and austempered at $300^{\circ}C$ and $400^{\circ}C$ for different holding times, and then quenched in ice water to obtain the multi-phase(Ferrite-Bainite-Martensite) structure from various prior structures, which was obtained by various cyclic heat treatments. As the number of cycle in cyclic heat treatment increased, volume fraction of pearlite increased and the its morphology was refined. As the number of cycle in cyclic heat treatment increased, the multi-phase(Ferrite-Bainite-Martensite) was dispersed in whole matrix as refined island phase. Particularly, martensite among the multi-phase gradually became a spherical shape. Good combination in impact energy and tensile strength was detained in $840^{\circ}C-300^{\circ}C-15min$ condition after 10 cycles in cyclic heat treatment, and its multi-phase volume fraction is Ferrite(50%)-Martensite(l3%)-Bainite(37%).

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
• /
• pp.507-510
• /
• 1988

The main subject of this paper is the development of new ROBOT CONTROLLER, which can support MULTI-TASKING and MULTI-ROBOT functions. The system consists of various kinds of CPU modules according to their independent jobs. Acceleration and Deceleration profile is given in order to achieve the smooth robot motion and high cycle time. Further the communication capacity should be upgraded to meet the various kinds of peripheral PA devices.

• 전력전자학회논문지
• /
• 제17권5호
• /
• pp.393-400
• /
• 2012

The modularized equalizers normally use additional components among the modules in the long series-connected lithium-ion battery string. In these approaches, the overall systems are heavy, bulky, and high-priced. Furthermore, the losses related to additional components decrease the system efficiency. To avoid these problems, a modularized equalizer, which has no additional components among the modules, is required. This paper proposes a novel control scheme using the magnetizing energy of the multi-winding transformer for the module equalization. In this scheme, the high duty cycle is applied to the module where the voltage is higher than the reference voltage and the low duty cycle is applied to the module where the voltage is lower than the reference voltage. Due to the different duty cycle, more electric charges are transferred from high voltage module to the low voltage module during the turn-off switching interval. Using the proposed control scheme, the equalizer system does not suffer from the size, cost, and loss related to the modularization. The experimental results are provided to verify the effectiveness of the proposed modularized equalizer.

• 방사성폐기물학회지
• /
• 제17권1호
• /
• pp.47-58
• /
• 2019

The paper presents the results of a multi-criteria comparative evaluation of 12 feasible Russian nuclear energy deployment scenarios with thermal and fast reactors in a closed nuclear fuel cycle. The comparative evaluation was performed based on 6 performance indicators and 5 different MCDA methods (Simple Scoring Model, MAVT / MAUT, AHP, TOPSIS, PROMETHEE) in accordance with the recommendations elaborated by the IAEA/INPRO section. It is shown that the use of different MCDA methods to compare the nuclear energy deployment scenarios, despite some differences in the rankings, leads to well-coordinated and similar results. Taking into account the uncertainties in the weights within a multi-attribute model, it was possible to rank the scenarios in the absence of information regarding the relative importance of performance indicators and determine the preference probability for a certain nuclear energy deployment scenario. Based on the results of the uncertainty/sensitivity analysis and additional analysis of alternatives as well as the whole set of graphical and attribute data, it was possible to identify the most promising nuclear energy deployment scenario under the assumptions made.

• 한국기계가공학회지
• /
• 제15권1호
• /
• pp.103-109
• /
• 2016

The performance of a multi-head, computerized combination scaling system to automatically identify a group of agricultural products having a total weight within the target range has been optimized to reduce the package cycle time of the merchandise. First, the structure of the scale was modified to enable faster measurement by enhancing the dynamic stability during the process. Second, the high frequency noise in the measured signal was eliminated by a high frequency filter to provide more accurate weight data. Finally, the algorithm to identify a group of products with a total weight within the target range was modified to enable a user to select an optimal number of scales. According to the experimental verifications, this modified system reduced the package cycle time significantly and also was accurate in measuring the total weight of the selected products.

• 전력전자학회논문지
• /
• 제19권5호
• /
• pp.415-421
• /
• 2014

This study proposes a model-based predictive control for interleaved multi-phase DC/DC converters. The power values necessary to adjust the output voltage in the succeeding are predicted using a converter model. The output power is controlled by selecting the optimal duty cycle. The proposed method does not require controller loops and modulators for converter switching. This method can control the converter by calculating the optimal duty cycle, which minimizes the error between the reference and actual output voltage. The effectiveness of the proposed method is verified through simulations and experiments.

• International Journal of Automotive Technology
• /
• 제5권3호
• /
• pp.165-172
• /
• 2004

Phenomenological models for direct injection diesel engine emissions including NO, soot, and HC were implemented into a full engine cycle simulation and validated with experimental data obtained from representative heavy-duty DI diesel engines. The cycle simulation developed earlier by Jung and Assanis (2001) features a quasi-dimensional, multi-zone, spray combustion model to account for transient spray evolution, fuel-air mixing, ignition and combustion. In this study, additional models for HC emissions were newly implemented and the models for NO, soot, and HC emissions were validated against experimental data. It is shown that the models can predict the emissions with reasonable accuracy. However, additional effort may be required to enhance the fidelity of models across a wide range of operating conditions and engine types.

• 대한기계학회논문집A
• /
• 제27권4호
• /
• pp.499-506
• /
• 2003

The design cycle associated with large engineering systems requires an initial decomposition of the complex system into design processes which are coupled through the transference of output data. Some of these design processes may be grouped into iterative subcycles. In analyzing or optimizing such a coupled system, it is essential to determine the best order of the processes within these subcycles to reduce design cycle time and cost. This is accomplished by decomposing large multidisciplinary problems into several sub design structure matrices (DSMs) and processing them in parallel This paper proposes a new method for parallel decomposition of multidisciplinary problems to improve design efficiency by using the multi-objective genetic algorithm and two sample test cases are presented to show the effect of the suggested decomposition method.

• 대한기계학회논문집A
• /
• 제32권8호
• /
• pp.642-653
• /
• 2008

In this paper, we propose a 3-D finite element (FE) analysis model with combined physical behavior and kinematical impact factors for evaluation of residual stress in multi-impact shot peening. The FE model considers both physical behavior of material and characteristics of kinematical impact. The physical parameters include elastic-plastic FE modeling of shot ball, material damping coefficient, dynamic friction coefficient. The kinematical parameters include impact velocity and diameter of shot ball. Multi-impact FE model consists of 3-D symmetry-cell. We can describe a certain repeated area of peened specimen under equibiaxial residual stress by the cell. With the cell model, we investigate the FE peening coverage, dependency on the impact sequence, effect of repeated cycle. The proposed FE model provides converged and unique solution of surface stress, maximum compressive residual stress and deformation depth at four impact positions. Further, in contrast to the rigid and elastic shots, plastically deformable shot produces residual stresses closer to experimental solutions by X-ray diffraction. Consequently, it is confirmed that the FE model with peening factors and plastic shot is valid for multi-shot peening analyses.