• Journal of Digital Convergence
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• v.20 no.5
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• pp.211-220
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• 2022

This paper proposes a green closed-loop supply chain network (GCSN) for optimizing closed-loop supply chains. The GCSN focuses on the application of the recycling express box in logistics circulation, accelerates the standardization of logistics operations and the use of express packaging in e-commerce companies, and promotes the reduction and greening of recycling express box in the e-commerce industry. The GCSN is represented as a mathematical formulation and implemented using LINGO. Greening, environmental protection, and wisdom are the general trends for promoting the growth of the e-commerce industry. Meanwhile, the price of raw materials has increased owing to a shortage of resources, which emphasizes the need for e-commerce enterprises to develop green packaging. Therefore, this study considers the shared circular packaging launched by e-commerce enterprises as the research object, and integrates the problem of facility positioning and path planning in the logistics system. The conclusion summarizes the significance of this study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1854-1862
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• 2001

In this paper, power flow characteristics of a hydromechanical transmission(HMT) are investigated using network analysis. The HMT used in this study consist of a hydrostatic unit(HSU), planetary gear sets, clutches and brakes providing forward 4 speeds and backward 2 speeds. Since the HMT power flows showing a closed loop and the HSU efficiency varies depending on the pressure and speed, a systematic approach is required to analyze the power transmission characteristics of the HMT. In order to analyze the closed loop power flow and the HSU power loss which changes depending on the pressure and speed, network model is constructed fur each speed range. In addition, an algorithm is proposed to calculate an accurate HSU loss corresponding to the experimental results. It is found from the network analysis that the torque and speed of each transmission element including the HSU can be obtained as well as direction of the power flow by the proposed algorithm. It is expected that the network analysis can be used in the design of relatively complicated transmission system such as HMT.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.519-524
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• 2001

In this paper, power flow characteristics of a hydromechanical transmission(HMT) are investigated using network analysis. The HMT used in this study consist of a hydrostatic unit(HSU), planetary gear sets, clutches and brakes providing forward 4 speeds and backward 2 speeds. Since the HMT power flows showing a closed loop and the HSU efficiency varies depending on the pressure and speed, a systematic approach is required to analyze the power transmission characteristics of the HMT. In order to analyze the closed loop power flow and the HSU power loss which changes depending on the pressure and speed, network model is constructed for each speed range. In addition, an algorithm is proposed to calculate an accurate HSU loss corresponding to the experimental results. It is found from the network analysis that the torque and speed of each transmission element including the HSU can be obtained as well as direction of the power flow by the proposed algorithm. It is expected that the network analysis can be used in the design of relatively complicated transmission system such as HMT.

• Journal of the Korean Professional Engineers Association
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• v.45 no.2
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• pp.33-37
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• 2012

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.74-74
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• 2000

This paper presents a neural network controller for a rigid-link electrically-driven robot. The proposed controller is designed in conjunction with three neural networks approximating for complicated nonlinear functions. Particularly, the fact, different from conventional schemes, is that the neural network based current observer is used. Therefore, no accurate measurement of the actuator driving current is required. In the proposed controller-observer scheme, the derived weight update rule guarantees the stability of closed-loop system in the sense of Lyapunov. The effectiveness and performance of the proposed method are demonstrated through computer simulation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.2
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• pp.181-192
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• 2015

A new communication revolution such as social networking service (SNS) has been transforming the way of interaction between people in both of individual level and organizational level. Recently many people have switched to closed type SNS such as Naver Band and Kakao group due to the several reasons. The purpose of this study is to investigate the usage motivation and satisfaction of SNS based on use and gratifications perspectives. Based on prior studies on use and gratifications of Internet-related media and SNS, information motivation, relationship motivation, pleasure/entertainment motivation, self-expression motivation, work motivation were identified as usage motivation of SNS. This empirical study explores how these motivations vary between open type SNS(facebook and twitter) and closed type SNS(band and kakao group). This study contributes to provide the base of activation strategies and practical implications for companies using SNS as a marketing tool.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.6
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• pp.494-501
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• 2001

In this paper an ANFIS(Adativo Neuro-Fuzzy Inference System)- based fault detection and diagnosis for a closed loop control system is proposed. The proposed diagnostic system contains two ANFIS. One is run as a parallel model within the model in closed loop control(MCL) and the other is run as a series-parallel model within the process in closed loop(PCL) for the generation of relevant symptoms for fault diagnosis. These symptoms are further processed by another classification logic with simple rules and neural network for process and controller fault diagnosis. Experimental results for a DC shunt motor control system illustrate the effectiveness of the proposed diagnostic scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.680-682
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• 2022

The closed-loop supply chain's central enterprises aim to maximize the revenue and reduce the reclaiming channel level to the greatest extent by using blockchain and modern management methods. The traditional recycling network has more links, and there is less communication between enterprises in each link. There is a particular "bullwhip effect" in the channel link, making it difficult for power battery manufacturers to respond to the dynamic market quickly. It is often challenging to obtain scaled waste power batteries, which aggravates how power battery raw materials are expensive and difficult to recycle. Therefore, the closed-loop supply chain design of power batteries adopting blockchain shall minimize channel links and reduce transaction levels to reduce costs.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.1
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• pp.197-207
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• 2015

A new communication revolution such as social networking service (SNS) has been transforming the way of interaction between people in both of individual level and organizational level. Recently many people have switched to closed type SNS such as Naver Band and Kakao group due to the several reasons. The purpose of this study is to investigate the usage motivation and satisfaction of closed type SNS based on use and gratifications perspectives. Based on prior studies on use and gratifications of Internet-related media and SNS, information motivation, relationship motivation, pleasure/entertainment motivation, self-expression motivation, work motivation were identified as usage motivation of closed type SNS. According to the results, relationship motivation and work motivation were found to be significantly related to the satisfaction. But other motivation factors(information motivation, pleasure/entertainment motivation, self-expression motivation) are not significantly related to the satisfaction. Then satisfaction was found to be significantly related to the intention to use. This study contributes to give companies providing closed type SNS and using it as a marketing tool with the base of activation strategies and practical implications.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.29-36
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• 2016

A wireless passive sensor network is a network which, by letting separate RF sources supply energy to sensor nodes, is able to live an eternal life without batteries. Against expectations about an eternal life, however, a wireless passive sensor network still has many problems; scarcity of energy, non-simultaneity of energy reception and data transmission and inefficiency in resource allocation. In this paper, we focus on a wireless passive sensor network providing a packet service which is tolerable to packet losses but requires timely delivery of packets. Perceiving the practical constraints, we then consider a contending-type MAC scheme, rooted in framed and slotted ALOHA, for supporting many sensor nodes to deliver packets to a sink node. Next, we investigate the network-wide throughput achieved by the MAC scheme when the packets transmitted by geographically scattered sensor nodes experience path losses hence capture phenomena. Especially, we derive an exact formula of network-wide throughput in a closed form when 2 sensor nodes reside in the network. By controlling design parameters, we finally optimize the contending-type MAC scheme as to attain the maximum network-wide throughput.