• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.11a
• /
• pp.229-231
• /
• 2012

The supply chain in plant construction project can be defined as a network combined between elements which is engineering, procurement, construction, start-up. For successfully leading construction project, close relation and mutual cooperation should be preceded and Supply Chain Management(SCM) system is needed to improve the relation. In particular, because safety is a top priority for the companies work in the construction of Nuclear Power Plant(NPP), it is necessary to control all parties realated with NPP construction systematically. In this situation, it is important to purchase high-quality equipment in timely manner by developing Integrated cooperative systems. Therefore, this study aimed to propose developing solutions of SCM such as JIT and Envelop Design system, which can reduces difficulties of decision making between the parties involved in the project and will increase the efficiency of the engineering process in NPP.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.9 s.339
• /
• pp.61-72
• /
• 2005

This paper proposes a method which efficiently allocates decoupling capacitance to reduce power supply noise at the floorplan level. We observe problems of previous approach that the decoupling capacitance of each module was overestimated and the power supply noises of modules were changed by inserting additional area for decoupling capacitance, and then suggest a new approach. And, we also present a simple heuristic method which can effectively allocate white space modules for decoupling capacitance area within more faster time instead of LP technique. Experimental results show that our approach can reduce the area of decoupling capacitance to average 7.9 percent compared with Zhao's approach in [4]. Therefore both total area and wire length of nniflm result are decreased. Also, we confirm that our approach solves well the problem caused by inserting additional area. In execution time comparison, our approach shows average 11.6 percent improvement.

• Korean Journal of Construction Engineering and Management
• /
• v.4 no.3 s.15
• /
• pp.85-94
• /
• 2003

The goal of enterprises is to make a profit. They should change and evolve themselves according to various customers' demand and developing information technology. The construction industry has not been used to such a change of business environment, although it has a long history. So it needs a new management system that accepts the various demands of construction participants and keeps pace with the evolving environment where is replaced by high-valued one. In this point, this research's objective is to apply SCM which shows visible outcome in the manufacturing industry, to the construction industry. This study regards the concept of SCM not as a simple management method, but as a comprehensive one. In other words, SCM is composed of three viewpoints; control, organization and information technology. SCM is to improve process by new management method, to benefit each other by strategical cooperation among participants, and to make information delivery and saving system for maintaining the relationship.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2397-2399
• /
• 2004

This paper deals with the messages scheduling of a CAN (Controller Area Network), based on the distributed control scheme to integrate actuators and sensors in a humanoid robot. In order to supply the distributed processing for a humanoid robot, each control unit should have the efficient control method, fast calculation and valid data exchange. The preliminary study has concluded that the performance of CAN is better and easier to implement than other network such as FIP (Factory Instrumentation Protocol), VAN (Vehicle Area Network), etc. Since humanoid robot has to treat the significant control signals from many actuators and sensors, the communication time limitation could be critical according to the transmission speed and data length of CAN specification. In this paper, the CAN message scheduling in humanoid robot was suggested under the presence of Jitter in the message group, the existence of high load of messages over the network and the presence of transmission errors. In addition, the response time under the worst case is compared with the simulation by using the simulation algorithm. As a result, the suggested messages scheduling can guarantee our CAN limitation, and utilized to generate the walking patterns for the humanoid.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.1
• /
• pp.121-131
• /
• 2004

Transportation and logistics of agricultural products have been one of the major interests of many researches. Most of researches have been limited to presuming these as a first dimensional process or considering only economic value of agricultural products at each stage of logistics. However, the particular characteristics of agricultural products, such as quality change during transportation or extensively scattered origins, require examining these problems as a whole system. Network model has been adopted to represent nodes, which stand for spatial location of demand and supply of agricultural products, and communication between these nodes. Based on network theory and advanced marketing potential function, an optimal routes selection model is developed. The model employed network simplex method for routes optimization. The application of the model focused on transportation network organization to reflect different market prices for different locations and resulted in optimum routes and profit improvement of the applied agricultural product.

• Journal of Institute of Control, Robotics and Systems
• /
• v.9 no.4
• /
• pp.304-309
• /
• 2003

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. The maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system. In order to realize these tasks autonomously, the three dimensional position of target object such as electric line and the stand of insulator must be recognized accurately and rapidly. The approaching of an insulator and the wrenching of a nut task is selected as the typical task of the maintenance of active electric power distribution lines in this paper. Image recognition by multilayer neural network and optimal target position calculation method are newly proposed in order to recognize the center 3 dimensional position of the bolt hole in the stand of insulator. By the proposed image recognition method, it is proved that the center 3 dimensional position of the bolt hole can be recognized rapidly and accurately without regard to the pose of the stand of insulator. Finally the approaching and wrenching task is automatically realized using 6-link electro-hydraulic manipulators.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.2
• /
• pp.279-288
• /
• 2017

The Material Transportation Capability Analysis Method in North Korea includes adversary's activities such as destruction of bridge which is one kind of choke points in the road network and surprise attack against resupply march unit. Also, the amount of damage on choke points in the road network and repair time depending on repair unit commitment must be reflected. In this study, a scenario encompassing plausible resupply transportation circumstances while counterattacking into NK will be established. Then, based on such scenario, a simulation model will be established and the result of simulation will be compared to the results of numeric example which has been used in the ROK Army. We demonstrate, through a certain Corps operation area, that the Scenario-based Simulation Model results predict the performance of resupply operation very well. Therefore, it makes sustainment planners and commanders do activities which is suitable for battlefield and should be used in the real situation. It is also a stochastic model.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.169-169
• /
• 2023

Most distributed water is not used effectively due to water loss occurring in pipe networks. These water losses are caused by leakage, typically due to high water pressure to ensure adequate water supply. High water pressure can cause the pipe to burst or develop leaks over time, particularly in an aging network. In order to reduce the amount of leakage and ensure proper water distribution, it is important to apply pressure management. Pressure management aims to maintain a steady and uniform pressure level throughout the network, which can be achieved through various operational schemes. The schemes include: (1) installing a variable speed pump (VSP), (2) introducing district metered area (DMA), and (3) operating pressure-reducing valves (PRV). Applying these approaches requires consideration of various hydraulic, economic, and environmental aspects. Due to the different functions of these approaches and related components, an all-together optimization of these schemes is a complicated task. In order to reduce the optimization complexity, this study recommends a sequential optimization method. With three network operation schemes considered (i.e., VSP, DMA, and PRV), the method explores all the possible combinations of pressure management paths. Through sequential optimization, the best pressure management path can be determined using a multiple-criteria decision analysis (MCDA) to weigh in factors of cost savings, investment, pressure uniformity, and CO₂ emissions. Additionally, the contribution of each scheme to pressure management was also described in the application results.

• International Journal of Computer Science & Network Security
• /
• v.24 no.1
• /
• pp.31-44
• /
• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.1
• /
• pp.8-13
• /
• 2022

This paper investigates the method to implement a RF (Radio Frequency) energy harvesting sensor node and to build a sensor network using a CATV network and a leaky coaxial cable. The power supply of a sensor node is designed with the WPTS (Wireless Power Transfer System) receiver operating at 915MHz. A sensor network has limited coverage by the loss of RF signal at a wireless transmission link. The paper proposes to build a sensor network that the BLE signal of a sensor and the signal of a WPTS power transmitter are transmitted through a coaxial cable of a CATV network by utilizing WOC (WiFi over Coax) technology and radiates at a leaky coaxial cable. The length of a leaky coaxial cable and the total loss of a wire link are allowed to the point that the RSSI of a sensor node is more than the minimum value (-78dBm) and lead to extend wireless coverage.