• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1434-1437
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• 2010

본 논문은 철강공정을 위한 미들웨어 구조를 제시하였다. 제안된 미들웨어는 커널 코어, 철강공정에 필요한 각 서비스 기능, 응용 소프트웨어와의 연결을 유지하는 채널 매니저, 응용 소프트웨어의 서비스 요구를 처리하는 API 핸들러, 미들웨어 사용 API로 구성된다. 제안된 미들웨어는 분산환경을 지원하며, 산업체에서 주로 사용되는 운영체제들을 지원하도록 구현하였다. 제안된 미들웨어에 대해 각 서비스의 성능이 측정되었으나, 지면상 본 논문에는 동기 메시지 서비스, 타이머 서비스의 성능만을 제시하였다. 또한 제안된 미들웨어를 철강공정 중 하나인 열간압연공정에 적용한 결과, 기존 상용 미들웨어를 사용한 환경에 비해 응답시간 성능이 30-35% 향상하였음을 보였다.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.8
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• pp.432-444
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• 2004

In this paper, we construct the TMO-based object group model on distributed environment, and analyze and evaluate the executability for distributed real-time service of our object group model by developing the distributed real-time application simulator applying the model. The Time-triggered Message-triggered Object(TMO) is a real-time server object having real-time property itself. The TMO-based object group is defined as a set of objects which logically reconfigured the physically distributed one or more TMOs on network by a given distributed application. For supporting group management of the server objects, the TMO-based object group we suggested provides the functions which register and withdraw the solver objects as a group member to an arbitrary object group, and also provides the functions which insert and delete the access rights of server objects from clients. Also, our model was designed and implemented to support the appropriate object selection and dynamic binding service for a single TMO as well as the duplicated TMOs, and to support the real-time scheduling service for the clients which are requesting the service. Finally, we developed the Defence System against Invading Enemy Planes(DSIEP) simulator as a practical example of distributed real-time application by applying our model, and evaluated the adaptability of distributed service strategies for the group components and the executability of real-time services that the TMO-based object group model provides.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2481-2490
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• 2015

The issue of PHR is maintained on the server will be in the hospital. PHR information stored on the server, such as a patient's illness and treatment is very sensitive information. Therefore, patients should be guaranteed the protection of privacy. In addition, the PHR should be allowed to group access of it's approach. Therefore, in this paper the proposed group signature using hierarchical identity-based encryption schemes into can guarantee the PHR data privacy. The session key generated by group signature, it is use a tiered approach. The generated session keys safe PHR data transmission is possible. The proposed method is average 80% than the PKI encryption and ID-based encryption rather than average 50% the algorithm processing is more efficient

• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.245-263
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• 2010

Today, large enterprises are changing their team organization to group organization. These trends have brought work flexibility of project and manpower usage. However, communication among group members has become more complicated, and it has been found that ERP was not efficient enough to solve this communication problem. The main purpose of this study was to design a quick and systematic communication system for group project management, and Web-based Information Reporting System (hence forth WIRS) has been proposed. The main topics covered in this paper are design of functions and system architecture, process model design, database design, and implementation of the prototype. Focus group interview was conducted and user feedback was positive about main functions for WIRS and its overall impact on the enhancement of productivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1B
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• pp.1-7
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• 2008

In group location management, when a transportation system(TS) with multiple mobile subscribers(MSs) changes location area(LA), location management is performed by group location registration by TS, instead of individual location registrations by MSs. In previous works, although it is assumed that LA in group location management is the same as that in individual location management, it is not appropriate to assume the same sized LAs since MSs in a TS have different characteristics from MSs which are not in a TS from the aspect of the speed and aggregate call arrival rates. Thus, in this paper, we propose an efficient location management scheme based on individual and group location managements with different sized LAs, and the performance of the proposed scheme is analyzed from the aspect of signaling cost at the wireless interface. Results reveal that the proposed scheme outperforms the conventional scheme by selecting an appropriate sized LA for group location management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2623-2631
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• 2010

In this paper, we propose a new interference cancellation(IC) receiver for multirate Multicarrier DS/CDMA(MC DS/CDMA) system based on orthogonal variable spreading factor(OVSF) code. The users are assigned different lengths of OVSF codes as a spreading code according to their data rates and the active users having same representative code split into a group for effective cancellation. The code grouping interference cancellation(IC) receiver performs cancellation between the groups first and cancellation within group. This proposed IC receiver can cancel the interferences using desired user's code information and then desired signals are detected. The results show that the large improvement in performance can be attained by group-wise IC scheme and we can make the effective systems compare to conventional ones. The bit error rate of the system is analytically derived in frequency selective Rayleigh fading channel and we also compare the system performance with that of multirate DS/CDMA system. We also analyze the performance of the proposed system with same bandwidth and processing gain. The results show the large improvement in performance that can be attained by cancellation scheme.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.219-225
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• 2022

In this paper, we propose a CAC exploring a RA based dynamic spectrum hole grouping for secondary users' QoS enhancement in multi-classes cognitive radio networks. The RA based dynamic spectrum hole grouping uses SU multi-classes overlaying spectrum structure suggested here. Multiclass SUs are divided into real and non real, and real SUs have a priority for resource utilization against non real. The amount of resource required by real SUs is supported by Wiener prediction and the dynamic spectrum hole grouping, and that required by non real SU is supported by the remained available amount without prediction. In the simulations, we compare the proposed CAC performances using the dynamic spectrum hole grouping in terms of SU connection's blocking(dropping) rate and resource utilization efficiency according to multi-classes traffic characteristics, and then we show the proposed CAC can guarantee the desired QoS of multi-classes secondary users.

• Journal of Internet Computing and Services
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• v.11 no.5
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• pp.105-117
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• 2010

In recent years, dynamic collaboration (DC) among cloud providers (CPs) is becoming an inevitable approach for the widely use of cloud computing and to realize the greatest value of it. In our previous paper, we proposed a combinatorial auction (CA) based cloud market model called CACM that enables a DC platform among different CPs. The CACM model allows any CP to dynamically collaborate with suitable partner CPs to form a group before joining an auction and thus addresses the issue of conflicts minimization that may occur when negotiating among providers. But how to determine optimal group bidding prices, how to obtain the stability condition of the group and how to distribute the winning prices/profits among the group members in the CACM model have not been studied thoroughly. In this paper, we propose to formulate the above problems of cooperative negotiation in the CACM model as a bankruptcy game which is a special type of N-person cooperative game. The stability of the group is analyzed by using the concept of the core and the amount of allocationsto each member of the group is obtained by using Shapley value. Numerical results are presented to demonstrate the behaviors of the proposed approaches.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.629-636
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• 2013

There is no safety evaluation index with marine accidents and information of ship's safety management result for good grasp of safety management level of shipping company and effective monitoring. In this paper, we proposed a SMEI(Safety Management Evaluation Index) for evaluation of shipping companies. The SMEI is consist of MAR(marine accidents ratio), SSMR(ship safety management ratio) and SAP(safety advantage point) through brainstorming of the expert group and AHP(analysis hierarchy process)in previous study. And weights of SMEI are calculated using experts's opinions through the Delphi method. We also verified the validity of proposed SMEI to 119 Korean shipping companies with 916 ocean-going ships of Korean flag, which grouped three part (small, mid and big) by number of ship and gross tonnage. And we found out 19 shipping companies, 8 companies in group1 & group2 respectively and 3 companies in group 3, with score below 1.0 by SMEI. In these companies, there are no marine accidents in recent 3 years and appeared low frequency remarkably in the detention and mojor non-conformity by data analysis.

• Korean small business review
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• v.43 no.4
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• pp.173-209
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• 2021

Start-up accelerators are a new type of investor that provide mentoring, education and seed capital to start-ups for a fixed duration and receive a certain stake in them in return. They help start-ups achieve successful commercialization. With increase in performance visibility, the number of private and public sector accelerators rose across domestic and international markets. Private sector accelerators are established and operated by private entities while public sector accelerators are established and operated by the government. Both play complementary roles that are becoming increasingly important to start-ups. Therefore, this study aims to examine the differences in major operational goals and investment determinants between private and public sectors and to understand their implications. The results show that the private sector prioritizes profit generation through the investment, while the public sector aims to contribute to the development of high-growth start-ups, and create region-specific and technology-specific start-up ecosystems. Additionally, both groups consider customer needs the most important determinant. Public groups are more conservative in investments and tend to place importance on objective indicators such as patents, partners, mentors, and co-founders. Conversely, private groups value the capabilities of founders and their ease of collaboration with accelerators. These findings can help start-ups get support from public or private accelerators more easily. It will also help public and private accelerators refine the criteria for selecting start-ups.