• 인지과학
• /
• 제17권3호
• /
• pp.231-253
• /
• 2006

시각형과 언어형이라는 인지양식이 멀티미디어 학습에 영향을 미치는지 알아보기 위해 언어정보와 그림정보의 제시순서를 달리해서 실험을 실시하였다. 시각형에서는 그림정보를 먼저 제시한 경우에 더 잘 학습하였으나, 언어형은 언어정보를 먼저 제시한 경우에 수행이 좋았다. 이 결과는 인지 양식에 따라 정보의 효과적인 제시 순서가 달라질 수 있다는 것을 보여주는 것으로, 학습자의 인지양식에 따라 학습교재의 인지 부하가 달라질 수 있다는 것을 시사하였다.

• 한국통신학회논문지
• /
• 제27권8A호
• /
• pp.753-762
• /
• 2002

Blind equalization of transmission channel is important in communication areas and signal processing applications because it does not need training sequences, nor dose it require a priori channel information. In this paper, an adaptive blind MMSE channel equalization technique based on second-order statistics in investigated. We present an adaptive blind MMSE channel equalization using multichannel linear prediction error method for estimating cross-correlation vector. They can be implemented as RLS or LMS algorithms to recursively update the cross-correlation vector. Once cross-correlation vector is available, it can be used for MMSE channel equalization. Unlike many known subspace methods, our proposed algorithms do not require channel order estimation. Therefore, our algorithms are robust to channel order mismatch. Performance of our algorithms and comparisons with existing algorithms are shown for real measured digital microwave channel.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2013년도 추계학술발표대회
• /
• pp.287-289
• /
• 2013

Fast Handover for Proxy Mobile IPv6 (FPMIPv6), a protocol described in RFC 5949, is used to reduce handover latency and minimize packet loss problem occuring in the Proxy Mobile IPv6 (PMIPv6) protocol. However, during the study of implementing FPMIPv6, we found the Out-of-Order Packet (OoOP) problem that occurs in the experiment of FPMIPv6. Since the OoOP is an issue that affects significantly to QoS of the network, in this paper, we analyze the OoOP problem by using network model. The analysis conducts the cause of occurring OoOP problem due to there exist two paths for data transmitted from Correspondent Node (CN) to MN in FPMIPv6.

• 한국정보시스템학회지:정보시스템연구
• /
• 제18권1호
• /
• pp.77-95
• /
• 2009

In customer-oriented make-to-order manufacturing environments, the works of BOM changes due to the changes of product specification and engineering are closely connected with almost all departments such as sales, engineering, production, procurement, cost, after service, etc within an enterprise. So, the contents of BOM changes must be instantly reflected on the related works among the departments. To effectively process these complex works of BOM changes, types of changes on product specification and engineering and types of BOM changes linked with those must be systematically defined, classified and managed by information systems. Thus, it is necessary to introduce solutions such as BPM and SOA in order to efficiently deal with complex business processes like BOM change management. This paper proposes a methodology of constructing information systems based on BPM and SOA. The proposed methodology defines the relationship between processes of BPM for definition, execution, monitoring, etc of business processes and services of SOA for connection among information systems within an enterprise, and presents a scheme of practically applying BPM and SOA solutions to actual business works. To show an utilization of the proposed methodology, the prototype system for product BOM management is implemented in order to efficiently deal with the works of BOM changes due to the changes of product specification and engineering.

• 한국통신학회논문지
• /
• 제39B권6호
• /
• pp.350-359
• /
• 2014

최근 급격한 인터넷의 발전으로 효율적인 네트워크관리를 위해 응용 트래픽 데이터 분석의 중요성이 강조되고 있다. 네트워크 관리를 위해 관리자는 트래픽 데이터를 각각 어떠한 응용에서 발생 하였는지 탐지할 수 있어야 한다. 응용을 탐지하기 위한 방법들 중 하나인 통계정보 트래픽 분류방법을 사용하여 트래픽을 분류할 수 있지만, 이러한 통계정보를 그대로 사용하여 분류하기에는 트래픽 수집지점에서 발생하는 패킷 역전, 재전송에 의한 패킷 중복과 같은 문제점들이 있다. 본 논문에서는 응용에서 발생된 트래픽의 탐지 및 분석률 향상을 위해 패킷 역전 문제와 재전송에 의한 패킷 중복 문제를 탐지하고 개선하는 방법론을 제안하였다. 이렇게 제안한 개선 방법론을 실제 트래픽 분석 시스템에 적용시킴으로써 응용별 바이트 기준 최대 4%의 탐지 및 분석률 향상을 보였다. 이는 제안한 방법론이 실제 트래픽 망에 부담을 줄 수 있는 heavy 플로우의 분석에 기여함을 확인하였다.

• 문화기술의 융합
• /
• 제7권4호
• /
• pp.879-892
• /
• 2021

수주생산 환경에서 제조업체의 견적정보는 다양한 고객요구에 대응하여, 프로젝트의 입찰, 수주, 그리고 생산할 제품의 기초정보로 사용하는 중요한 정보이다. 이 견적정보는 고객요구, 제품생산 환경의 변화, 기술제휴사의 도면정보 변경, 그리고 제품의 기술 개선 등의 여러 요인에 의해 변경된다. 이러한 변경으로 인하여, 제조사가 고객의 요구사항을 반영하여 작성중인 견적정보에 다양한 변경이 발생한다. 이러한 다양한 변경요인에 따른 견적정보의 변경은 수주생산 기업의 입장에서 견적관리업무에 많은 부담을 주고 있다. 특히, 견적의 변경요인으로 인한 견적정보 변경은 고객중심의 주문생산 환경에서 고객의 요구사항에 의해 불가피하고 빈번하게 발생한다. 본 논문에서는 견적생성 프로세스를 기준으로 견적변경 프로세스를 제시하고, 일관적이고 효율적인 견적변경처리 방안을 제시하고자 한다. 이를 위하여, 견적의 변경이 발생하는 요인을 정의하고, 각 요인에 대한 변경유형을 정의하였다. 그리고 견적변경에 대한 발생 요인별 사례를 통하여 견적변경 프로세스가 견적관리시스템에 적용되는 과정을 보여준다. 또한 제안된 견적변경 요인, 견적변경 유형, 견적변경 프로세스, 그리고 견적체계 관리의 유용성을 보여주기 위하여, 고객 중심의 수주생산기업인 'H'사의 선박엔진 부문의 통합 견적관리시스템에서의 견적변경처리 기능 및 절차에 적용하였다. 그 결과, 견적변경 요인에 따른 견적변경 처리 및 관리가 효율적으로 수행됨을 확인하였다.

• 복식
• /
• 제38권
• /
• pp.289-304
• /
• 1998

In Korean clothing industry, most of the manufactures produce garments by subcon-tractors partially or entirely. It is very often that the design part is remote from production part and there is miscommunication between these two parts resulting dissatisfaction to both. Therefore it is very important to communicate the manufacturing information clearly and quickly to produce garments exactly the design part intended. Also to automate the clothing out how to produce and use the information objectively and efficiently. As a first step of moving to automation, the purpose of the research is to find out how manufacturing information and data are communicated in clothing manufacturing at present. In order to follow the information flow of a cer-tain manufacturer, the case study method was used. The case study samples were 12 clothing firms of 13 brands. The results and suggestions are as follows :- 1. A manufacturing information is communicated through paper documents such as“Production Order”, sample and patterns. At present, a production order sheet is the most efficient communication media, which comprises most of the information being communicated. 2. A manufacturing information comprises control information on the product, design in-formation, pattern information, cutting information, material information, sewing information, production schedule information, quality control information, costing information and information about the subcontractors. 3. A manufacturing is not quite objective except pattern information and cutting information which is presented by CAD systems. The communication of design information and sewing information should be somehow more objective. 4. There is not much information from a subcontractor. Considering that a subcontractor is the other partener of the communication, more information from the subcontractor is required for both benefit. 5. A designer produce most of the manufacturing information, but the information is communicated through a production manager to the subcontractor. The difference between the information maker and information communicator can cause any miscommunication. In future automated manufacturing, it will be possible for the designer to communicate to the manufacturer directly from the early stage of designing.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1007-1011
• /
• 2003

In this paper, a design of I-PDA controller by CDM to control a flow process whose structure is first order lag plus a dead time is introduced. The factor of dead time of the process is approximated by second order Pade approximation in order to get a third order system. The simulations show that both of the transient and steady state specifications can be fulfilled. However, the transient response of the I-PDA control system still has long rise time. Then, a feedforward controller (FFC) with two adjustable parameters and one derivative time is introduced into I-PDA control system for improving the speed of the system response. It is shown, from the simulation results, that the performance of the I-PDA control system with suitable FFC has shorter rise time and no overshoot, while settling time remains almost the same. The performance comparison of the proposed control system with the PI control system with and without FFC is also made.

• Journal of Computing Science and Engineering
• /
• 제8권2호
• /
• pp.94-106
• /
• 2014

Schema matching is widely used in many applications, such as data integration, ontology merging, data warehouse and dataspaces. In this paper, we propose a novel matching technique that is based on the order of attributes appearing in the schema structure of query results. The appearance order embodies the extent of the importance of an attribute for the user examining the query results. The core idea of our approach is to collect statistics about the appearance order of attributes from the query logs, to find correspondences between attributes in the schemas to be matched. As a first step, we employ a matrix to structure the statistics around the appearance order of attributes. Then, two scoring functions are considered to measure the similarity of the collected statistics. Finally, a traditional algorithm is employed to find the mapping with the highest score. Furthermore, our approach can be seen as a complementary member to the family of the existing matchers, and can also be combined with them to obtain more accurate results. We validate our approach with an experimental study, the results of which demonstrate that our approach is effective, and has good performance.

• Journal of Information Processing Systems
• /
• 제14권5호
• /
• pp.1087-1101
• /
• 2018

As cloud computing has become a widespread technology, malicious attackers can obtain the private information of users that has leaked from the service provider in the outsourced databases. To resolve the problem, it is necessary to encrypt the database prior to outsourcing it to the service provider. However, the most existing data encryption schemes cannot process a query without decrypting the encrypted databases. Moreover, because the amount of the data is large, it takes too much time to decrypt all the data. For this, Programmable Order-Preserving Secure Index Scheme (POPIS) was proposed to hide the original data while performing query processing without decryption. However, POPIS is weak to both order matching attacks and data count attacks. To overcome the limitations, we propose a group order-preserving data encryption scheme (GOPES) that can support efficient query processing over the encrypted data. Since GOPES can preserve the order of each data group by generating the signatures of the encrypted data, it can provide a high degree of data privacy protection. Finally, it is shown that GOPES is better than the existing POPIS, with respect to both order matching attacks and data count attacks.