• 전자공학회논문지A
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• 제32A권9호
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• pp.142-151
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• 1995

The trend of compact size, light weight, low power consumption in the portable telecommunication equipments demands large scale integration and low voltage operation of chips and the minimization of the number of the components in the telecommunication terminal. According to the trend, existing chip components are modulized and are integrated as a part into a bigger chip. This paper is about the development of the peripheral units of micro-controller for mobile telecommunication terminal. Peripherals consist of DMA controller, Interrupt controller, timer, watchdog timer, clock generator, and power management unit. They are designed to be integrated with EU(Execution Unit) and BIU(Bus Interface Unit) into a 16 bit micro-controller which will be used as a core of an ASIC for next generation digital mobile telecommunication terminal. At first, whole block of the micro-controller was described by VHDL behavioral model and simulated to verify its overall operation. Then, watchdog timer, clock generator and power management unit were directly synthesized by using VHDL synthesis tool. Rest of the pheriperal units were designed and simulated by using Compass Design Tool.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.2302-2316
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• 2015

We propose an efficient method of extracting targets within a region of interest in non-homogeneous infrared images by using a principal component analysis (PCA) plane and adaptive Gaussian kernel. Existing approaches for extracting targets have been limited to using only the intensity values of the pixels in a target region. However, it is difficult to extract the target regions effectively because the intensity values of the target region are mixed with the background intensity values. To overcome this problem, we propose a novel PCA based approach consisting of three steps. In the first step, we apply a PCA technique minimizing the total least-square errors of an IR image. In the second step, we generate a binary image that consists of pixels with higher values than the plane, and then calculate the second derivative of the sum of the square errors (SDSSE). In the final step, an iteration is performed until the convergence criteria is met, including the SDSSE, angle and labeling value. Therefore, a Gaussian kernel is weighted in addition to the PCA plane with the non-removed data from the previous step. Experimental results show that the proposed method achieves better segmentation performance than the existing method.

• 한국항해학회지
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• 제5권1호
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• pp.1-23
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• 1981

As far as transportation problems are concerned, the minimization of transportation cost is the most prevailing object. But in some cases, the cargo delivery time is the utter problem rather than the cost. For instance, we may imagine the case that the delivery of the construction materials is delayed behind the schedule and this makes the construction cost increased because of idle time of other materials and man power, in addition to the indemnity. Therefore the allocation of ships, in marine transportation which is now the main route of overseas trade, to the needed area on the required time is to be appropriately performed. However, there are several restrictions for cargo delivery to meet the demand, such as ship's size, number to be employed and cargo handling capacity of the ports, etc. And there are some other factors to be considered, that is, the degree of necessities of commodities, on their kinds, amount, and the time of arrival, etc. This paper deals with the problem of optimum allocation of ships emphasizing the cargo delivery time adopting Linear Programming technique with those cargo delivery restrictions and factors transformed by introducing the multi-speed conception, the conversion of multi-commodity to a single commodity, allowable delivery time, weight penalty number and nominating priority. This paper presents a case of optimum allocation of ships in the light of cargo delivery time for a construction company which has two different construction places and analyzes the result. This study will give a planner a good tool for optimum planning of maring transportation and be used for decision of schemes.

• 한국산업융합학회 논문집
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• 제11권3호
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• pp.127-134
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• 2008

This study is to develop the structure analysis and optimization algorithm of the strut supported temporary structure for underground constructions. Developed algorithm performs the analysis and the optimization of each strut, wale, and H pile of temporary structures separately. The design variables of nonlinear optimization consist of the cross-sections of temporary structures such as strut, wale, and H pile and the solution of the nonlinear programming is searched using for the method of successive unconstranint minimization technique. The weight of the structure is used for the object function of nonlinear programming. the constraints are derived from the specification of the temporary structures as compressive axial, bending, shear, composite stress and serviceability. The structural analysis is performed based on the elastoplastic beam theory. This developed program can be used to evaluate the applicability, convergence, and effectiveness of the temporary structures.

• 대한기계학회논문집
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• 제14권3호
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• pp.594-602
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• 1990

본 연구에서는 동력전달용 인벌류우트 원통치차(스퍼어 및 헬리컬 기어)의 강 도 및 각종 영향인자를 충분히 고려하면서 크기를 최소로 하는 치차장치의 설계법을 개발하고, 이 설계법을 기본으로 하여 퍼스널 컴퓨터 상에서 누구나 손쉽게 설계에 이 용할 수 있는 설계 시스템을 개발하여 그 평가를 수행한다.

• Structural Engineering and Mechanics
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• 제23권1호
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• pp.29-42
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• 2006

This paper describes the design scheme of the three-dimensional structures based on the concept of the cellular automata simulation. The cellular automata simulation is performed according to the local rule. In this paper, the local rule is derived in the mathematical formulation from the optimization problem. The cell density is taken as the design variable. Two objective functions are defined for reducing the total weight of the structure and obtaining the fully stressed structure. The constraint condition is defined for defining the local rule. The penalty function is defined from the objective functions and the constraint condition. Minimization of the penalty function with respect to the design parameter leads to the local rule. The derived rule is applied to the design of the three-dimensional structure first. The final structure can be obtained successfully. However, the computational cost is expensive. So, in order to reduce the computational cost, the material parameters $c_1$ and $c_2$ and the value of the cell rejection criterion (CRC) are changed. The results show that the computational cost depends on the parameters and the CRC value.

• International Journal of Aerospace System Engineering
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• 제2권2호
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• pp.29-33
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• 2015

The multidisciplinary design optimization (MDO) of a launch vehicle (LV) with a hybrid rocket engine (HRE) was carried out to investigate the ability of an HRE for a single-stage LV. The non-dominated sorting genetic algorithm-II (NSGA-II) was employed to solve two design problems. The design problems were formulated as two-objective cases involving maximization of the downrange distance over the target flight altitude and minimization of the gross weight, for two target altitudes: 50.0 km and 100.0 km. Each objective function was empirically estimated. Several non-dominated solutions were obtained using the NSGA-II for each design problem, and in each case, a trade-off was observed between the two objective functions. The results for the two design problem indicate that economical performance of the LV is limited with the HRE in terms of the maximum downrange distances achievable. The LV geometries determined from the non-dominated solutions were examined.

• 한국통신학회논문지
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• 제39A권5호
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• pp.237-243
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• 2014

이 논문에서는, 영확률을 최대화 (maximum zero-error probability, MZEP) 하도록 설계된 알고리듬에서 가중치 갱신에 쓰이는 기존의 블록 처리 방식의 합산 연산을 대신하여, 다음 기울기 계산에 현재 계산된 기울기를 활용할 수 있는 효율적인 가중치 갱신 계산 방식을 제안하였다. 실험 결과로부터, 제안한 방식은 원래의 MZEP 와 동일한 성능을 나타내면서도 오차 버퍼가 불필요하여 시스템의 복잡도를 감소시키며 연산 시간을 현저히 줄일 수 있다. 또한 제안한 알고리듬은 오차 엔트로피 (error-entropy)를 최소화하도록 설계된 알고리듬보다 우수한 수렴 속도를 지닌다.

• 한국산업융합학회 논문집
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• 제13권2호
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• pp.77-84
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• 2010

Recently, the concept of structural design against instability has been proposed in the chassis parts. The design considerations of lower control arm of chassis parts under the buckling and durability strengths are the general. More precisely, this paper considers a specific application and associated optimization problem for two strengths, where the design variables are the physical or geometric dimensions for skins and stiffeners. The objective is the minimization of the total weight, while optimization constrains involve reserve or improve factors for the buckling and durability strengths. The most important features are related to the numerical simulations for the estimation of buckling factor and their sensitivities by means of nonlinear and linear finite element analyses. The bucking and durability strength analyses, and the morping geometries are directly included in the optimization problem and the modified design is formulated. As a result, the optimal structure with stable behavior is obtained or increases the buckling and durability strengths of parts. Most of design problems for structures exposed to elastic instability can be formulated and solved.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.53-63
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• 2022

In the paper, we propose a TSCH-based scheduling scheme for IEEE 802.15.4e, which is able to perform the scheduling of its own network by avoiding collision from interference network cluster (INC). Firstly, we model a bipartite graph structure for presenting the slot-frame (channel-slot assignment) of TSCH. Then, based on the bipartite graph edge weight, we utilize the Hungarian assignment algorithm to implement a scheduling scheme. We have employed two features (maximization and minimization) of the Hungarian-based assignment algorithm, which can perform the assignment in terms of minimizing the throughput of INC and maximizing the throughput of own network. Further, in this work, we called the scheme "dual-stage Hungarian-based assignment algorithm". Furthermore, we also propose deep learning (DL) based deep neural network (DNN)scheme, where the data were generated by the dual-stage Hungarian-based assignment algorithm. The performance of the DNN scheme is evaluated by simulations. The simulation results prove that the proposed DNN scheme providessimilar performance to the dual-stage Hungarian-based assignment algorithm while providing a low execution time.