• Title/Summary/Keyword: Commercial complex

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Study on the design optimization of injection-molded DVD-Tray parts using CAE Simulation (플라스틱 DVD-Tray의 박막 사출성형을 위한 최적화 설계 Simulation에 관한 연구)

  • Chung, Jae-Youp;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1726-1732
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    • 2008
  • Injection molding is one of plastic forming technology which can easily mass-produce plastic parts with various and even complex shape. The technology has lots of difficulties in making a good part due to phase change of material, high applied pressure, and fast melt flow speed in the cavity. To overcome the problems, they had to make trial and error method until the CAE(Computer Aided Engineering) could be a tool for concurrent engineering. In this paper, we investigate the optimal design for a plastic DVD tray part by systematic approach of the commercial CAE program. In design, we should consider two objectives which are both dimensional stability and cost-down. The dimension of the part is crucial because the tray should carry a DVD correctly, but the part is too thin to injection-mold easily. In order to improve the moldability, the mold is designed in the form of stack mold which is a kind of 4 hot runner system. In first, we changed the stack-mold system with one hot-runner to cost down, and decided the optimal position of the gate. After that, we investigate the effect of both the layout of cooling channels and the cooling temperature on the shrinkage of the DVD tray. A optimal simulation approach, the gate design is 2Gate#3 and the layout is Case2 cooling line as the optimal temperature of $70^{\circ}C$. The Moldflow and PC+ABS are used for the CAE program and material respectively.

The extension of the IDEA Methodology for a multilevel secure schema design (다단계 보안 스키마 설계를 위한 IDEA 방법론의 확장)

  • Kim, Jung-Jong;Park, Woon-Jae;Sim, Gab-Sig
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.3
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    • pp.879-890
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    • 2000
  • Designing a multilevel database application is a complex process, and the entities and their associated security levels must be represented using an appropriate model unambiguously. It is also important to capture the semantics of a multilevel databse application as accurate and complete as possible. Owing to the focus of the IDEA Methodology for designing the non-secure database applications on the data-intensive systems, the Object Model describes the static structure of the objects in an application and their relationships. That is, the Object Model in the IDEA Methodology is an extended Entity-Relationship model giving a static description of objects. The IDEA Methodology has not been developed the multilevel secure database applications, but by using an existing methodology we could take advantage of the various techniques that have already been developed for that methodology. That is, this way is easier to design the multilevel secure schema than to develop a new model from scratch. This paper adds the security features 새? Object Model in the IDEA Methodology, and presents the transformation from this model to a multilevel secure object oriented schema. This schema will be the preliminary work which can be the general scheme for the automatic mapping to the various commercial multilevel secure database management system such as Informix-Online/Secure, Trusted ORACLE, and Sybase Secure SQL Server.

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Hybrid Mobile IP Protocol for Service Session Continuity between WiBro and HSDPA (WiBro와 HSDPA 망간 서비스 연속성을 제공하기 위한 Hybrid Mobil IP 프로토콜)

  • Kim, Sung-Jin;Choi, Woo-Jin
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.223-228
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    • 2008
  • Recently, various types of wireless access networks, such as WLAN, WiBro and HSDPA, etc, have been successfully deployed by commercial service providers (i.e., KT, KTF). In this situation, there are many efforts to provide high quality of services to guarantee seamless mobility between heterogeneous networks. The IP layer mobility protocols are efficient mechanisms to provide seamless mobility between IP based heterogeneous networks as well as homogeneous networks. However, to apply IP mobility protocols in real heterogeneous networks (i.e., WiBro and HSDPA), we must consider not only the basic features of techniques of wireless access networks (i.e., Data rate, Coverage, Quality of Service) but also the problem of real environment of service provider (i.e., Expanse cost to change the access network). Due to this reason, it is difficult to satisfy required conditions by using only one IP mobility protocol in real heterogeneous networks. Therefore, in this paper, we propose an efficient mobility protocol to solve the complex problems that are occurred in real heterogeneous networks. The proposed protocol, so-called, "Hybrid Mobile IP" tries to provide a synergy effect by integrating Client Mobile IPv4 (CMIPv4) and Proxy Mobile IPv4 (PMIPv4), and using the two mobility protocols selectively according to the situation of real heterogeneous networks.

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Analysis of Network Traffic with Urban Area Characteristics for Mobile Network Traffic Model (이동통신 네트워크 트래픽 모델을 위한 도시 지역 이동통신 트래픽 특성 분석)

  • Yoon, Young-Hyun
    • The KIPS Transactions:PartC
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    • v.10C no.4
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    • pp.471-478
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    • 2003
  • Traditionally,, analysis, simulation and measurement have all been used to evaluate the performance of network protocols and functional entities that support mobile wireless service. Simulation methods are useful for testing the complex systems which have the very complicate interactions between components. To develop a mobile call simulator which is used to examine, validate, and predict the performance of mobile wireless call procedures must have the teletraffic model, which is to describe the mobile communication environments. Mobile teletraffic model is consists of 2 sub-models, traffic source and network traffic model. In this paper, we analyzed the network traffic data which are gathered from selected Base Stations (BSs) to define the mobile teletraffic model. We defined 4 types of cell location-Residential, Commercial, Industrial, and Afforest zone. We selected some Base Stations (BSs) which are represented cell location types in Seoul city, and gathered real data from them And then, we present the call rate per hour, cail distribution pattern per day, busy hours, loose hours, the maximum number of call, and the minimum number of calls based on defined cell location types. Those parameters are very important to test the mobile communication system´s performance and reliability and are very useful for defining the mobile network traffic model or for working the existed mobile simulation programs as input parameters.

Correlation between Microstructure and Mechanical Properties of the Additive Manufactured H13 Tool Steel (적층 제조된 H13 공구강의 미세조직과 기계적 특성간의 상관관계)

  • An, Woojin;Park, Junhyeok;Lee, Jungsub;Choe, Jungho;Jung, Im Doo;Yu, Ji-Hun;Kim, Sangshik;Sung, Hyokyung
    • Korean Journal of Materials Research
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    • v.28 no.11
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    • pp.663-670
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    • 2018
  • H13 tool steels are widely used as metallic mold materials due to their high hardness and thermal stability. Recently, many studies are undertaken to satisfy the demands for manufacturing the complex shape of the mold using a 3D printing technique. It is reported that the mechanical properties of 3D printed materials are lower than those of commercial forged alloys owing to micropores. In this study, we investigate the effect of microstructures and defects on mechanical properties in the 3D printed H13 tool steels. H13 tool steel is fabricated using a selective laser melting(SLM) process with a scan speed of 200 mm/s and a layer thickness of $25{\mu}m$. Microstructures are observed and porosities are measured by optical and scanning electron microscopy in the X-, Y-, and Z-directions with various the build heights. Tiny keyhole type pores are observed with a porosity of 0.4 %, which shows the lowest porosity in the center region. The measured Vickers hardness is around 550 HV and the yield and tensile strength are 1400 and 1700 MPa, respectively. The tensile properties are predicted using two empirical equations through the measured values of the Vickers hardness. The prediction of tensile strength has high accuracy with the experimental data of the 3D printed H13 tool steel. The effects of porosities and unmelted powders on mechanical properties are also elucidated by the metallic fractography analysis to understand tensile and fracture behavior.

A Study on the Current Status and Challenge of Core Project in Urban Regeneration -Focused on the Type of Central Commercial District- (도시재생사업에서 핵심사업의 추진 현황과 과제 -중심시가지형 사업 추진 사례를 중심으로-)

  • Kim, Young-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.819-828
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    • 2021
  • In urban regeneration projects, the core projects define the characteristics of the project site and contribute to the highest project cost and drive the project forward. The purpose of this study was to identify the current status and characteristics of the project as a priming project for urban regeneration and to seek desirable alternatives in the future project process. For this purpose, the case of urban regeneration projects in the Chungcheong region was targeted. The results showed that the core projects for each case consisted mainly of projects to develop physical facilities on a relatively large scale. Securing large-scale complex base space and constructing public parking lots are planned as key projects. In addition, based on the cost composition of the priming project, the core project accounted for approximately 80 % of the total project, and the project cost between linked projects does not appear to be relatively well linked in both public and private investment sectors. These findings are expected to help promote substantial urban regeneration projects and enhance efficiency by using them as basic data for urban regeneration projects in the future.

A Study on the Method of Manufacturing Lactic Acid from Seaweed Biomass (해조류 바이오매스로부터 Lactic acid를 제조하는 방법에 관한 연구)

  • Lee, Hakrae;Ko, Euisuk;Shim, Woncheol;Kim, Jongseo;Kim, Jaineung
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.1
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    • pp.1-8
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    • 2022
  • With the spread of COVID-19 worldwide, non-face-to-face services have grown rapidly, but at the same time, the problem of plastic waste is getting worse. Accordingly, eco-friendly policies such as carbon neutrality and sustainable circular economy are being promoted worldwide. Due to the high demand for eco-friendly products, the packaging industry is trying to develop eco-friendly packaging materials using PLA and PBAT and create new business models. On the other hand, Ulva australis occurs in large quantities in the southern seas of Korea and off the coast of Jeju Island, causing marine environmental problems. In this study, lactic acid was produced through dilute acid pretreatment, enzymatic saccharification, and fermentation processes to utilize Ulva australis as a new alternative energy raw material. In general, seaweeds vary in carbohydrate content and sugar composition depending on the species, harvest location, and time. Seaweed is mainly composed of polysaccharides such as cellulose, alginate, mannan, and xylan, but does not contain lignin. It is difficult to expect high extraction yield of the complex polysaccharide constituting Ulva australis with only one process. However, the fusion process of dilute acid and enzymatic saccharification presented in this study can extract most of the sugars contained in Ulva australis. Therefore, the fusion process is considered to be able to expect high lactic acid production yield when a commercial-scale production process is established.

BEEF MEAT TRACEABILITY. CAN NIRS COULD HELP\ulcorner

  • Cozzolino, D.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1246-1246
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    • 2001
  • The quality of meat is highly variable in many properties. This variability originates from both animal production and meat processing. At the pre-slaughter stage, animal factors such as breed, sex, age contribute to this variability. Environmental factors include feeding, rearing, transport and conditions just before slaughter (Hildrum et al., 1995). Meat can be presented in a variety of forms, each offering different opportunities for adulteration and contamination. This has imposed great pressure on the food manufacturing industry to guarantee the safety of meat. Tissue and muscle speciation of flesh foods, as well as speciation of animal derived by-products fed to all classes of domestic animals, are now perhaps the most important uncertainty which the food industry must resolve to allay consumer concern. Recently, there is a demand for rapid and low cost methods of direct quality measurements in both food and food ingredients (including high performance liquid chromatography (HPLC), thin layer chromatography (TLC), enzymatic and inmunological tests (e.g. ELISA test) and physical tests) to establish their authenticity and hence guarantee the quality of products manufactured for consumers (Holland et al., 1998). The use of Near Infrared Reflectance Spectroscopy (NIRS) for the rapid, precise and non-destructive analysis of a wide range of organic materials has been comprehensively documented (Osborne et at., 1993). Most of the established methods have involved the development of NIRS calibrations for the quantitative prediction of composition in meat (Ben-Gera and Norris, 1968; Lanza, 1983; Clark and Short, 1994). This was a rational strategy to pursue during the initial stages of its application, given the type of equipment available, the state of development of the emerging discipline of chemometrics and the overwhelming commercial interest in solving such problems (Downey, 1994). One of the advantages of NIRS technology is not only to assess chemical structures through the analysis of the molecular bonds in the near infrared spectrum, but also to build an optical model characteristic of the sample which behaves like the “finger print” of the sample. This opens the possibility of using spectra to determine complex attributes of organic structures, which are related to molecular chromophores, organoleptic scores and sensory characteristics (Hildrum et al., 1994, 1995; Park et al., 1998). In addition, the application of statistical packages like principal component or discriminant analysis provides the possibility to understand the optical properties of the sample and make a classification without the chemical information. The objectives of this present work were: (1) to examine two methods of sample presentation to the instrument (intact and minced) and (2) to explore the use of principal component analysis (PCA) and Soft Independent Modelling of class Analogy (SIMCA) to classify muscles by quality attributes. Seventy-eight (n: 78) beef muscles (m. longissimus dorsi) from Hereford breed of cattle were used. The samples were scanned in a NIRS monochromator instrument (NIR Systems 6500, Silver Spring, MD, USA) in reflectance mode (log 1/R). Both intact and minced presentation to the instrument were explored. Qualitative analysis of optical information through PCA and SIMCA analysis showed differences in muscles resulting from two different feeding systems.

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A Study on Practical Implications in the Contract for International Transfer of Technology -Focused on Character of the Technology compared with Goods- (국제기술이전계약 체결시 실무상 유의점에 관한 연구 - 물품과 비교하여 기술이 가지는 성격을 중심으로 -)

  • Jeong, Hee-Jin
    • Korea Trade Review
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    • v.42 no.1
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    • pp.27-45
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    • 2017
  • A new phenomenon in recent trade is the rising interest in the trade of product production and manufacturing methods themselves, unlike in the past, when the interest was focused on the trade of tangible goods. That is, technology is considered as the object of trade instead of a simple element of production as "technology itself is commercialized". The broad meaning of technology encompasses all the property of knowledge with economic value. Its narrow meaning refers to technology used to produce and manufacture goods. Technologies have features such as no forms, heterogeneity, accumulation of value and extinction of right. The trade of technology commands different styles and content from that of tangible goods due to their unique characteristics; and accordingly, has various risk factors. In other words, technology can be traded in various ways according to commercial objectives including licensing, technical partnership, and joint investment in addition to general trading. The specific forms of technology transfer strategies depend on the purposes and situations between corporations. In case of technical trade with any form, the parties should be cautious about the following practical aspects: First, the contract should clearly define the scope and transfer method of technology. It is a very important matter how the provider of technology will provide the user of technology with abstract technology with no substantiality. Second, a monopoly on technology recognized as intellectual property rights is granted to their inventors for some periods of time, but anyone can have access to that technology after the term of existence. Thus, it is important to check the terms of existence of a patent as well as the terms of contract. Third, the user of technology should fulfill his confidentiality obligation to prevent the technology of the provider from being leaked to a third party unjustly. Fourth, the provider of technology should make a contribution to the successful implementation of the technology by the user as well as provide the licensed technology. Finally, a model contract is recommended to minimizing the legal hiatus of complex technology transfer trade when concluding a contract.

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Analysis for Circumstance of Maritime Transport in the Chinese northeastern three provinces towards Sustainable New Northern Policy

  • Junghwan Choi;Sangseop Lim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.4
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    • pp.121-131
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    • 2023
  • The Chinese three northeastern three provinces - Heilongjiang, Liaoning, and Jilin - hold significant geographical, geopolitical, and commercial importance due to their location allowing for cross-border trade and transportation with North Korea. These provinces are crucial for establishing a complex Eurasian logistics network in line with South Korea's new northern policy. The Chinese three northeastern three provinces, as this region is known, boasts excellent maritime transportation links between South Korea, China, and North Korea, making it an logistics hub for transporting goods to Eurasia and Europe through multimodal transport. This study highlights the importance of securing a logistics hub area by fostering cooperation and friendly relations with China's three northeastern three provinces, which are crucial to the success of the New Northern Policy. In particular, the study aims to analyze current status of trade with these region and freight volume transported by ships and recommend political advice for securing logistics hub and revitalizing maritime transport. As the policy suggestion, this study is to establish a logistics hub by implementing joint port operations, constructing port infrastructure jointly, and operating shipping companies together. Additionally, we propose ways to revitalize the maritime passenger transport business between Korea and China, which involves expanding cultural exchanges and developing content.