• Title/Summary/Keyword: Model following control systems

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A Study on the Development Strategy of Logistics System in E-Commerce in China

  • OH, Moon-Kap;YOUN, Myoung-Kil
    • The Journal of Economics, Marketing and Management
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    • v.7 no.4
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    • pp.1-5
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    • 2019
  • Purpose - Along with the rapid growth of the economics and IT industry, E-commerce appears as the next potential area of world economics. For this no-entity shops commerce style, logistics is crucial for the success of E-commerce. Research design, data and methodology - In this paper, Dangdang.com, the largest online marketplace in China, is studied and a conceptual model is present, to develop a practical way to develop the logistics system in E-commerce situation. Results - This research finds that following 4 factors are critical success factors for E-commerce logistics: 1) logistics centres are very important to control the inventory management; 2) keep good cooperation with third-party logistics (3PL) can guarantee good quality shipping service and also can reduce delivery costs; 3) build strong information system; 4) quick response system also needed for an efficient logistics system. When E-commerce firms are developing their logistics systems, they should pay more attention to these 4 critical success factors. Conclusions - In summary, successful 3PL management is vital for competing regionally and globally throughout the logistics value chain. We see information system as an enabler in logistics management to get the right products to the right place in the right quantity at the right time and to provide quality services to satisfy the customer's needs.

Oil Leak Analysis using Simulation Model of Hydraulic System for Dental Chair (치과용 유니트체어 유압구동 시스템 해석모델을 활용한 누유량 분석)

  • Dae Kyung Noh;Dong Won Lee;Jae Yong Kim;Joo Sup Jang
    • Journal of Drive and Control
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    • v.20 no.4
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    • pp.35-44
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    • 2023
  • This study aimed to analyze the performance of hydraulic systems for dental chair when long working hours makes the temperature of hydraulic fluid rise. The study was carried out in the following manner. First, 'cylinder's clearance' was reflected in the three kinds of hydraulic circuits, which were developed through the preceding study, in order to analyze oil leak. Second, 12 cases of simulations comprised of the up and down of cylinders were carried out. Third, it was determined whether the cylinder velocity of dental chair surpasses 1cm/s required in the development even in the hydraulic fluid temperature of 60℃. In conclusion, this study used SimulationX to verify the performance stability at high temperatures using three types of hydraulic circuits designed to develop a Korean unit chair.

Scene Generation of CNC Tools Utilizing Instant NGP and Rendering Performance Evaluation (Instant NGP를 활용한 CNC Tool의 장면 생성 및 렌더링 성능 평가)

  • Taeyeong Jung;Youngjun Yoo
    • IEMEK Journal of Embedded Systems and Applications
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    • v.19 no.2
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    • pp.83-90
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    • 2024
  • CNC tools contribute to the production of high-precision and consistent results. However, employing damaged CNC tools or utilizing compromised numerical control can lead to significant issues, including equipment damage, overheating, and system-wide errors. Typically, the assessment of external damage to CNC tools involves capturing a single viewpoint through a camera to evaluate tool wear. This study aims to enhance existing methods by using only a single manually focused Microscope camera to enable comprehensive external analysis from multiple perspectives. Applying the NeRF (Neural Radiance Fields) algorithm to images captured with a single manual focus microscope camera, we construct a 3D rendering system. Through this system, it is possible to generate scenes of areas that cannot be captured even with a fixed camera setup, thereby assisting in the analysis of exterior features. However, the NeRF model requires considerable training time, ranging from several hours to over two days. To overcome these limitations of NeRF, various subsequent models have been developed. Therefore, this study aims to compare and apply the performance of Instant NGP, Mip-NeRF, and DS-NeRF, which have garnered attention following NeRF.

Two-Stage Evolutionary Algorithm for Path-Controllable Virtual Creatures (경로 제어가 가능한 가상생명체를 위한 2단계 진화 알고리즘)

  • Shim Yoon-Sik;Kim Chang-Hun
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.11_12
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    • pp.682-691
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    • 2005
  • We present a two-step evolution system that produces controllable virtual creatures in physically simulated 3D environment. Previous evolutionary methods for virtual creatures did not allow any user intervention during evolution process, because they generated a creature's shape, locomotion, and high-level behaviors such as target-following and obstacle avoidance simultaneously by one-time evolution process. In this work, we divide a single system into manageable two sub-systems, and this more likely allowsuser interaction. In the first stage, a body structure and low-level motor controllers of a creature for straight movement are generated by an evolutionary algorithm. Next, a high-level control to follow a given path is achieved by a neural network. The connection weights of the neural network are optimized by a genetic algorithm. The evolved controller could follow any given path fairly well. Moreover, users can choose or abort creatures according to their taste before the entire evolution process is finished. This paper also presents a new sinusoidal controller and a simplified hydrodynamics model for a capped-cylinder, which is the basic body primitive of a creature.

Development of the Standard Worksheet System for the Quality Risk Management of Apparel Products (패션의류제품의 품질 리스크 관리를 위한 표준작업지시서 시스템 개발)

  • 이원자;유지선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.9_10
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    • pp.1160-1171
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    • 2003
  • This study is intended to examine the current situation and the problems of the "worksheets, regarding various factors that exert influences onto the quality-risk management, which is one of the most significant factors specifying an apparel product. This paper advances according to the following sequences: 1. Literature survey 2. Field research on actual "apparel vendors" and production factories 3. Investigating the requirements relating to the worksheet 4. Developing standard format of the worksheet 5. Effectiveness analysis on the standard worksheet 6. Proposal of an intelligent model applying standard worksheet system. This study is performed with the following research methods; those are questionnaire surveys, statistical analysis, interviews, collecting & analyzing worksheets, product sample quality experiment, functional analysis of the system, and materialization of the prototype system. The significance of this research is that it suggests the possible effective use of worksheet, which reflects the customers' needs in terms of the product quality, at the stage of the product planning process. Despite its importance, the current work structure does not visibly reflect these components. Therefore, with the result of this research, it is considered that the worksheet systems will meet more useful improvements in risk management process. The limitations of this research are as follows. Although it is evident that the standard worksheets bring effective results in quality improvements of products, considerations must be made onto some additional payoffs arising from the additional cost of necessary labor forces with expert knowledge and cost of the effort and time inputting correct information for running the system.

Dual Codec Based Joint Bit Rate Control Scheme for Terrestrial Stereoscopic 3DTV Broadcast (지상파 스테레오스코픽 3DTV 방송을 위한 이종 부호화기 기반 합동 비트율 제어 연구)

  • Chang, Yong-Jun;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.216-225
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    • 2011
  • Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

A Study on the Establishment of Priority for IT Project Management Using AHP (AHP 기법을 이용한 IT 프로젝트 관리 우선순위 수립에 대한 연구)

  • Kyung, Tae-Won;Kim, Sang-Kuk
    • Information Systems Review
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    • v.9 no.3
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    • pp.157-181
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    • 2007
  • Main concerns of IT project managements are concentrated on the output control and process management. IT project, however, is difficult to measure the quality of achievement, because it produces invisible and intangible outputs. Many studies have been carried on to quantify the intangible aspects of process management. However, most of them have been focused on the technological aspects. This study measures the priority of factors to manage IT project by applying the IT-BSC and PMBOK method. Established indexes include the factors of managerial, social and future-oriented perspectives to check the different aspects of project management over the technical factors. This study uses AHP method for quantitative measurement. This study can be meaningful because of following reasons. First, this study re-arranges IT project management evaluation indexes by balanced scorecard. Second, this model includes human factors of developers and users who are directly related to the project development and operation. Third, important items of each stakeholder have been separated, and the weights of each item have been quantified to have fixed values.

Effect of Ginseng on Calretinin Expression in Mouse Hippocampus Following Exposure to 835 MHz Radiofrequency

  • Aryal, Bijay;Maskey, Dhiraj;Kim, Myeung-Ju;Yang, Jae-Won;Kim, Hyung-Gun
    • Journal of Ginseng Research
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    • v.35 no.2
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    • pp.138-148
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    • 2011
  • Exponential rise in the use of mobile communication devices has generated health concerns due to radiofrequency (RF) exposure due to its close proximity to the head. Calcium binding proteins like calretinin regulate the levels of calcium ($Ca^{2+}$) which plays an important role in biological systems. Ginseng is known for maintaining equilibrium in the human body and may play a beneficial radioprotectant role against electromagnetic field (EMF) exposure. In the present study, we evaluated the radioprotective effects of red ginseng (RG) extract in a mouse model. Calretinin (CR) expression was measured using a free-floating immunohistochemical method in the hippocampus of mice after 835 MHz EMF exposure for 5 h/d for 5 d at specific absorption rate=1.6 W/kg for the different experimental groups. The control animals were treated with NaCl while the experimental animals received 10 mg/kg ginseng, or 30 mg/kg; EMF exposed mice were also treated with NaCl, 10 mg/kg ginseng (E10), or 30 mg/kg (E30). Decreases in CR immunoreactivity (IR) along with loss of CA1 and CA3 interneurons and infragranular cells were observed in the ENaCl group while such losses were not observed in the E10 and E30 groups. CR IR significantly increased in the RG-treated group compared to control and EMF-exposed groups treated with NaCl. The study demonstrates that RG extract can serve as a radioprotective agent that maintains $Ca^{2+}$ homeostasis and prevents neuronal loss in the brain hippocampal region caused by RF exposure.

The National Hospice Care Service Development in Korea (한국형 호스피스 케어 개발을 위한 기초 조사 연구)

  • Lee, Soo-Woo;Lee, Eun-Ok;Ahn, Hyo-Seog;Heo, Dae-Seock;Kim, Dal-Sook;Kim, Hyun-Sook;Lee, Hiye-Ja
    • The Korean Nurse
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    • v.36 no.3
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    • pp.49-69
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    • 1997
  • The urgent needs to establish hospice care systems in Korea arise from the following reasons: 0) a drastic increase in chronically ill patients with the increase of aged population: (2) rapid changes in living environment from the traditional habitation (e. g., Many Koreans living in apartment complexes, which is the most popular form of modern residence in recent years, prefer to die in the hospital.): the overall increase in patients with advanced cancer: (4) recent trends in early discharge of terminally ill patients from the limited hospital facilities to accomodate other medical insurance beneficiaries; (5) easy acceptance of euthanasia owing to the recent social atmosphere that belittles the dignity of human life; (6) medical and nursing care of AIDS patient in terminal stage; (7) and the problem associated with inhumane medical care system, overtreatment, and groundless fears against narcotics. Terminally ill patients were used to be treated in the hospital in the past. In these days, however, they are forced to have home cares with little assistance from the qualified medical personnel because of insufficient hospital facilities, which are even short for the need of emergency patients and provide priority cares to medical insurance beneficiaries with other acute problems. And yet, neither are there any administrative organizations nor systematic medical studies that deal with the level of terminally ill patient's need, their family's problems and resources of hospice care systems in Korea. Thus, most patients are not able to get appropriate medical care at the terminal stage of their lives. The objective of this study is to make comprehensive database for various hospice care organization currently in operation, link them through medical information system, and develop an easily accessible hospice care model that meets the need of most Korean people. Our survey results may be summarized as follows: Nationally there are 40 organizations that provide partial or full hospice care. However, these organizations are not linked to any formal medical service network. Furthermore, the objective of hospice care, care principles, personnel with appropriate training, educational programs, standard for care, costs, consulting service to patients' family members, the extent of medical care from professional staff members, status of hospice facility, and management of those institutions are neither clearly defined nor organized compared to the international hospice care standards. The surveys on patients of terminal stage. grouped in hospice and non-hospice care patients. reveal what they want visiting nursing care to help their pain control. psychological. social and spiritual demands. While the more than 90% of hospice care patients want to reduce their pains. the non-hospice care patients. in addition to their desire for pain control. demanded more psychological. social and spiritual helps as well. The results of this research could be utilized to 0) define the standard of hospice care. (2) provide the guidance for hospice medical care costs. (3) establish the database of hospice care systems. (4) develop softwares. (5) build communication network through Medinet. and (6) provide an organized visiting home nursing care system. These information should be a valuable resource to many medical staffs who are involved in cancer therapy. nursing care. and social welfare programs.

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EFFECT OF ANCHORAGE SYSTEMS ON LOAD TRANSFER WITH MANDIBULAR IMPLANT OVERDENTURES : A THREE-DIMENSIONAL PHOTOELASTIC STRESS ANALYSIS (하악 임플란트 overdenture에서 anchorage system이 하중전달에 미치는 영향)

  • Kim Jin-Yeol;Jeon Young-Chan;Jeong Chang-Mo
    • The Journal of Korean Academy of Prosthodontics
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    • v.40 no.5
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    • pp.507-524
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    • 2002
  • Load transfer of implant overdenture varies depending on anchorage systems that are the design of the superstructure and substructure and the choice of attachment. Overload by using improper anchorage system not only will cause fracture of the framework or screw but also may cause failure of osseointegration. Choosing anchorage system in making prosthesis, therefore, can be considered to be one of the most important factors that affect long-term success of implant treatment. In this study, in order to determine the effect of anchorage systems on load transfer in mandibular implant overdenture in which 4 implants were placed in the interforaminal region, patterns of stress distribution in implant supporting bone in case of unilateral vertical loading on mandibular left first molar were compared each other according to various types of anchorage system using three-dimensional photoelastic stress analysis. The five photoelastic overdenture models utilizing Hader bar without cantilever using clips(type 1), cantilevered Hader bar using clips(type 2), cantilevered Hader bar with milled surface using clips(type 3), cantilevered milled-bar using swivel-latchs and frictional pins(type 4), and Hader bar using clip and ERA attachments(type 5), and one cantilevered fixed-detachable prosthesis(type 6) model as control were fabricated. The following conclusions were drawn within the limitations of this study, 1. In all experimental models. the highest stress was concentrated on the most distal implant supporting bone on loaded side. 2. Maximum fringe orders on ipsilateral distal implant supporting bone in a ascending order is as follows: type 5, type 1, type 4, type 2 and type 3, and type 6. 3. Regardless of anchorage systems. more or less stresses were generated on the residual ridge under distal extension base of all overdenture models. To summarize the above mentioned results, in case of the patients with unfavorable biomechanical conditions such as not sufficient number of supporting implants, short length of the implant and unfavorable antero-posterior spread. selecting resilient type attachment or minimizing distal cantilever bar is considered to be appropriate methods to prevent overloading on implants by reducing cantilever effect and gaining more support from the distal residual ridge.