• 제목/요약/키워드: Processing Trade

검색결과 313건 처리시간 0.024초

DYMO 라우팅 프로토콜의 이동 속도와 트래픽 부하에 따른 경로 축적의 효율성 (Efficiency of Path Accumulation with DYMO Routing Protocol in Mobility and Load Environment)

  • 나권문
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2007년도 추계학술발표대회
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    • pp.1069-1072
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    • 2007
  • MANET에서의 전통적인 라우팅 프로토콜은 일반적으로 두 종류로 나눠지는데 proactive 라우팅 프로토콜과 on-demand 라우팅 프로토콜이다. 라우팅 정보의 proactive 전파와 reactive 발견 사이에는 필수적인 trade-off 가 존재한다. 모든 시나리오들을 충족하는 라우팅 프로토콜이 존재하지 않는 것은 분명하다. 그래서 최적의 라우팅 프로토콜을 발견하기 위한 연구가 계속되고 있으며 IETF의 MANET 워킹그룹은 여러 다른 프로토콜을 제안 중에 있고 그 중에 하나가 on-demand 라우팅 프로토콜의 AODV를 계승한 DYMO(Dynamic MANET On-demand)이다. DYMO는 경로 축적 메커니즘을 채택하였다. 경로 발견 과정에서 노드들은 라우팅 메시지를 포워딩하기 전에 그들 자신의 라우팅 정보도 패킷에 추가할 수 있다. 결국 소스와 목적지 사이의 모든 노드들의 라우팅 정보가 교환되는 것이다. 이 논문에서는 이 경로 축적 메커니즘의 사용 유무에 따라 다양한 속도와 트래픽 부하에서 DYMO의 성능이 어떻게 변하고 최적의 환경은 무엇인지 연구해보고자 한다.

순시신호 대 잡음비 알고리즘을 이용한 적응 잡음 제거기의 DSP 구현 (An Implementation of Adaptive Noise Canceller using Instantaneous Signal to Noise Ratio with DSP Processor)

  • 이재균;류부식;김춘식;이채욱
    • 융합신호처리학회논문지
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    • 제10권3호
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    • pp.158-163
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    • 2009
  • LMS(Least Mean Square) 알고리즘은 식이 간단하고 계산량이 비교적 적기 때문에 널리 사용되고 있다. 그러나 LMS 알고리즘은 수렴속도를 높이게 되면 주위 환경이 급격하게 변하는 경우 발산하게 되고, 안정성을 높이게 되면 수렴속도가 떨어지는 수렴속도와 안정성 사이에 trade-off가 발생한다. 이러한 LMS 알고리즘의 단점을 개선하기 위해 VSSLMS(Variable Step Size LMS) 알고리즘이 개발되었다. VSSLMS 알고리즘은 에러 신호를 이용하여 스텝사이즈를 조절하여 수렴속도와 성능을 동시에 향상시킨다. 본 논문에서는 실시간 환경에서 적응잡음 제거기의 성능을 개선시키기 위해 I-VSSLMS(Instantaneous Signal to Noise Radio VSSLMS)을 제안한다. 제안한 I-VSSLMS을 TMS320C6713 DSP 보드를 이용하여 적응 잡음 제거기에 적용하여, 실시간으로 시뮬레이션을 하였고, 각 알고리즘의 성능을 비교 분석하여 제안한 알고리즘의 성능이 우수함을 입증하였다.

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"무역상무(貿易商務)에의 역사적(歷史的) 어프로치와 무역취인(貿易取引)의 전자화(電子化)" (E-Commerce in the Historical Approach to Usage and Practice of International Trade)

  • 춘홍차
    • 무역상무연구
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    • 제19권
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    • pp.224-242
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    • 2003
  • The author believes that the main task of study in international trade usage and practice is the management of transactional risks involved in international sale of goods. They are foreign exchange risks, transportation risks, credit risk, risk of miscommunication, etc. In most cases, these risks are more serious and enormous than those involved in domestic sales. Historically, the merchant adventurers organized the voyage abroad, secured trade finance, and went around the ocean with their own or consigned cargo until around the $mid-19^{th}$ century. They did business faceto-face at the trade fair or the open port where they maintained the local offices, so-called "Trading House"(商館). Thererfore, the transactional risks might have been one-sided either with the seller or the buyer. The bottomry seemed a typical arrangement for risk sharing among the interested parties to the adventure. In this way, such organizational arrangements coped with or bore the transactional risks. With the advent of ocean liner services and wireless communication across the national border in the $19^{th}$ century, the business of merchant adventurers developed toward the clear division of labor; sales by mercantile agents, and ocean transportation by the steam ship companies. The international banking helped the process to be accelerated. Then, bills of lading backed up by the statute made it possible to conduct documentary sales with a foreign partner in different country. Thus, FOB terms including ocean freight and CIF terms emerged gradually as standard trade terms in which transactional risks were allocated through negotiation between the seller and the buyer located in different countries. Both of them did not have to go abroad with their cargo. Instead, documentation in compliance with the terms of the contract(plus an L/C in some cases) must by 'strictly' fulfilled. In other words, the set of contractual documents must be tendered in advance of the arrival of the goods at port of discharge. Trust or reliance is placed on such contractual paper documents. However, the container transport services introduced as international intermodal transport since the late 1960s frequently caused the earlier arrival of the goods at the destination before the presentation of the set of paper documents, which may take 5 to 10% of the amount of transaction. In addition, the size of the container vessel required the speedy transport documentation before sailing from the port of loading. In these circumstances, computerized processing of transport related documents became essential for inexpensive transaction cost and uninterrupted distribution of the goods. Such computerization does not stop at the phase of transportation but extends to cover the whole process of international trade, transforming the documentary sales into less-paper trade and further into paperless trade, i.e., EDI or E-Commerce. Now we face the other side of the coin, which is data security and paperless transfer of legal rights and obligations. Unfortunately, these issues are not effectively covered by a set of contracts only. Obviously, EDI or E-Commerce is based on the common business process and harmonized system of various data codes as well as the standard message formats. This essential feature of E-Commerce needs effective coordination of different divisions of business and tight control over credit arrangements in addition to the standard contract of sales. In a few word, information does not alway invite "trust". Credit flows from people, or close organizational tie-ups. It is our common understanding that, without well-orchestrated organizational arrangements made by leading companies, E-Commerce does not work well for paperless trade. With such arrangements well in place, participating E-business members do not need to seriously care for credit risk. Finally, it is also clear that E-International Commerce must be linked up with a set of government EDIs such as NACCS, Port EDI, JETRAS, etc, in Japan. Therefore, there is still a long way before us to go for E-Commerce in practice, not on the top of information manager's desk.

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An Empirical Assessment of Organizational Commitment and Job Performance: Vietnam Small and Medium-Sized Enterprises

  • VUONG, Bui Nhat;TUNG, Dao Duy;HOA, Nguyen Dinh;CHAU, Nguyen Thi Ngoc;TUSHAR, Hasanuzzaman
    • The Journal of Asian Finance, Economics and Business
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    • 제7권6호
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    • pp.277-286
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    • 2020
  • Research on employee commitment to the organization is necessary for human resource management, and the result is applied in practice to improve organizational effectiveness. The aim of the present study is to explore factors affecting organizational commitment at the small and medium-sized enterprises (SMEs) in Vietnam. Besides, the relationship between organizational commitment and job performance is examined as well. The research was conducted on a sample consisting of 67 white-collar workers and 260 blue-collar workers at SMEs. A total of 327 valid complete questionnaires were input into SPSS 20 database for processing to provide evidence. The research model and hypotheses were tested using the technique of the hierarchical multiple regression analysis. The research resultsrevealed that income, reward and welfare, direct manager, working environment, coworker, and promotion opportunity tended to associate positively with organizational commitment. Besides, the finding also showed that, when the employee has a high organizational commitment, it would lead to high job performance. The main findings of this study provided some managerial implications for SMEs, in general, and managers, in particular. It implies that Vietnam's small and medium-sized enterprises should improve these six factors to retain employees as well as enhance their job performance.

고속 EFEM의 성능평가시스템 개발 (Development of Performance Evaluation System for the High Speed EFEM)

  • 조정환;노희정
    • 조명전기설비학회논문지
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    • 제24권2호
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    • pp.27-32
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    • 2010
  • 본 논문은 반도체 공정에 사용되는 고속 EFEM(Equipment Front End Module) 장치의 새로운 성능평가시스템을 제안한다. 다관절 로봇으로 구성된 EFEM은 실리콘 웨이퍼 또는 포토마스크를 클린 스토리지 캐리어와 각종 계측 및 테스팅 시스템 사이를 이동시키는 반도체 자동화의 핵심장치이다. 성능평가 시스템 개발을 위한 이론과 실험적인 연구가 수행되었고, 그 결과는 고속 EFEM 장치의 성능 평가시스템이 적합함을 입증한다. 특히, WTO/TBT(Technical Barhers to Trade) 협정 및 PL(Product Liability)법에 대처하는데 매우 효과적이다.

UMTS의 DSCH를 위한 개선된 패킷 스케줄링 알고리즘 (An Improved Packet Scheduling Algorithm for DSCH of UMTS)

  • 조현준
    • 정보처리학회논문지C
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    • 제11C권6호
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    • pp.863-870
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    • 2004
  • 최근들어 UMTS(Universal Mobile Telecommunication System)는 3세대 무선망의 표준으로 인식되고 있고 DSCH(Down-link Shared Chanel)는 UMTS에서 매우 효율적인 다중화 방안으로 고려되고 있다. 그러므로 UMTS에서의 DSCH를 위한 효과적인 패킷스케줄링 알고리즘 개발에 대한 연구가 필수적이다. 본 논문은 UMTS의 DSCH를 위한 개선된 패킷스케줄링 알고리즘에 대하여 기술한다. 이 알고리즘은 최대 링크 이용율을 위하여 이동호스트채널상태를 고려하며, 동시에 장기적으로 공정성을 얻기 위해 3등급 트래픽에서의 지연 한계치와 4등급 트래픽의 처리율을 함께 이용한다. 알고리즘의 타당성을 보이기 위하여 PARSEC을 이용한 모의실험을 수행하였다. 모의실험 결과는 이 알고리즘이 무선링크 이용율과 공정성 두 가지 측면에서 적적한 타협(trade-off)을 통하여 개선된 결과를 얻을 수 있음을 보여준다.

Efficient Hardware Implementation of Real-time Rectification using Adaptively Compressed LUT

  • Kim, Jong-hak;Kim, Jae-gon;Oh, Jung-kyun;Kang, Seong-muk;Cho, Jun-Dong
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권1호
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    • pp.44-57
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    • 2016
  • Rectification is used as a preprocessing to reduce the computation complexity of disparity estimation. However, rectification also requires a complex computation. To minimize the computing complexity, rectification using a lookup-table (R-LUT) has been introduced. However, since, the R-LUT consumes large amount of memory, rectification with compressed LUT (R-CLUT) has been introduced. However, the more we reduce the memory consumption, the more we need decoding overhead. Therefore, we need to attain an acceptable trade-off between the size of LUT and decoding overhead. In this paper, we present such a trade-off by adaptively combining simple coding methods, such as differential coding, modified run-length coding (MRLE), and Huffman coding. Differential coding is applied to transform coordinate data into a differential form in order to further improve the coding efficiency along with Huffman coding for better stability and MRLE for better performance. Our experimental results verified that our coding scheme yields high performance with maintaining robustness. Our method showed about ranging from 1 % to 16 % lower average inverse of compression ratio than the existing methods. Moreover, we maintained low latency with tolerable hardware overhead for real-time implementation.

한국의 통관서비스 효율성 분석에 관한 연구 (Efficiency Analysis on Customs Clearance Service of Korea)

  • 이기웅
    • 무역상무연구
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    • 제53권
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    • pp.315-336
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    • 2012
  • In year 2011 export volume of South Korea surpassed 500billion USD and overall trade volume has exceeded one trillion USD. South Korea is ranked at 7th in the world by its export volume. Such an expansion of the trade volume leads to growth in customs clearance service demand. However, there are only handfuls of studies on the efficiency of customs clearance service which customs broker provide. If the efficiency in this study is not absolute, it shows relative efficiency to decision making unit. In this research survey was conducted targeting members of Korea Customs Brokers Association. Based on the survey improvement plans to enhance efficiency of customs clearances are as follows. First, rationalize the customs broker fee. Second, setup batch processing system to improve efficiency of the work process. Third, develop new area of task such as FTA and AEO certification. Forth, raise service quality by improving professionalism of customs brokers. Fifth, work efficiency of the office in the capital area will increase. Sixth, when inspecting import export cargo, customs broker should attend at the scene by their choice. Meanwhile, difference analysis on competent customs, type of office, and duration of the business was done but all the aspects were rejected. Such aspects does not influence on its effectiveness.

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실기간 소음제거를 위한 IGC Algorithm의 LabVIEW FPGA 구현 (Labview FPGA Implementation of IGC Algorithm for Real Time Noise Cancelation)

  • 김춘식;이채욱
    • 한국통신학회논문지
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    • 제36권3C호
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    • pp.183-189
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    • 2011
  • LMS알고리즘은 강인성, 높은 추성, 구현의 단순성 때문에 많이 사용되고 있지만, 비균일적 수렴과 EMSE사이에 trade-off를 가진다. 이러한 단점을 극복하기 위해 가변 스텝 사이즈 알고리즘 방식이 사용되는데, 많은 계산량을 필요로 한다. 본 논문에서 제안하는 IGC 알고리즘은 원 신호와 잡음신호의 순시이득값을 사용함으로서, 계산량을 줄이고, 주위 환경변화에도 안정적으로 적용할 수 있다. 실시간 처리를 위하여 IGC 알고리즘에서 log함수를 제거하여, 실제로 자동차 소음제거기에 적용하여 제안한 알고리즘의 성능을 확인하였다. 그리고 Labview FPGA 구현을 하여, 기존의 다른 알고리즘과 비교하여 효율적이라는 것을 입증하였다.

효율적인 글로벌 SCM에 적합한 국가 간 정보 연계를 위한 인터페이스 모델 연구 (A Study on the Interface Model of Information sharing between nations for an efficient global SCM)

  • 박수민;김민식;안경림
    • 디지털산업정보학회논문지
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    • 제8권4호
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    • pp.217-230
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    • 2012
  • To look at Korea trade environment, as increasing the quantity of goods transported in North-East Asia and deepening national competitive, information-oriented logistics environment is needed. That means it is automated work process and can provide value-added service. To do this, logistics business can be efficiently handled through "Electronic Means for the Clearance of Ships" and electronically data processing. Also, by increasing the risk of international terrorism, regulation regarding to logistics security has strengthened around the advanced country, such as USA and EU, etc. or international organization, such as IMO, ISO, etc.. Furthermore, because trade and logistics environment is changing and security becomes more important in logistics area, movement or status information of goods within the port or in entry in/out becomes more and more be needed in real time. In case cross-border logistics activities, international cooperation or agreement between countries is very important. However, different opinions much happened on defining the interface. If to follow one format or type using at a specific country or organization, it was occurred to difficulty in respect of interoperability as well as additional costs or time. Therefore, this paper proposes common interface model to exchange information for the efficient global SCM for using by the output of Korea R&D project, "National Logistics Standardization System Development".