• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
• /
• pp.312-319
• /
• 2003

In late 90s, organizations recognized the information technology as an key enabler of the business strategic accomplishment which lead them heavy increment on IT investment. These organizations tried to hold the competitive advantage by focusing on their core competency. And these acts raise their interests on IT outsourcing. Recent trends of the organizations concern on evaluating the effectiveness of the previous IT investment and the reasonable selection on IT investment type. Also, the objective evaluation of the service level and continuous improvement are major concern of the outsourcer. Consequently, interests on Service Level Agreement (SLA), an immanence operating tool for managing the level of the information system service objectively and qualitatively, were raised among IT outsourcing service providers, outsourcers, and operating departments. Yet, only a few domestic conglomerates adopted the SLA, and exact usage of the SLA is currently unknown. Because of the importance of the SLA between a service provider and an outsourcer, the agreement is treated with high confidentiality. This raised the problems to both the private and public organizations, are considering the SLA, with absence of concrete guide line to internalize SLA management process. This study provides the organizational and environmental factors of the adopting and applying the Service Level Agreement (SLA) by conducting multiple case research. The sampled companies are currently implementing the SLA over 1 year of usage period. Factors were used to provide the operational contribution for implementing the SLA. The study also provides the effects on IT performance through the SLA. For this, in depth interview was conducted for each sampled company. As a result, if SLA between outsourcer and service provider can be used as an immanence operation tool and actively implemented, SLA will be an strategic tool for various decision making in IT management practice with long term relationship, better shared partnership, and continuous service improvement.

• 한국산학기술학회논문지
• /
• 제10권3호
• /
• pp.684-694
• /
• 2009

본 연구에서는 지적재조사사업의 추진이 지연되고 있는 원인을 사업의 홍보부족에 의한 국민공감대 형성미흡에 있다고 판단하였다. 그래서 이러한 문제를 해결하고자 허들의 PR모델을 이용하여 지적재조사사업의 홍보 방안을 제시하여 보고자 하였다. 연구의 성과로서, 3차원의 6개 PR 실무 모델을 기초로 하여 각각의 홍보 실무에 적합하도록 총 31가지의 홍보수단에 따른 방법이 제시되었다. 그런데 일부 허들의 PR모델이 지적재조사사업의 성격과 부합되지 않는 부분이 도출되어 이를 재조사사업의 성격에 부합하도록 새로이 모델을 재정립하여 제시하였다. 본 연구의 성과는 향후 지적재조사사업의 조속한 시행을 위한 대국민 공감대 형성에 기반을 마련하는데 일조 할 수 있을 것으로 기대된다.

• 정보보호학회논문지
• /
• 제19권3호
• /
• pp.73-82
• /
• 2009

본 논문에서는 SIP UA와 서버 사이에서 HTTP Digest 인증과 TLS를 대신하여 효율적이고 안전한 사용자 인증 및 키 교환 기술을 제안한다. 기존에 다양한 SIP 인증 및 키 교환 기술들이 연구되었지만, 이동 단말과 같이 자원 활용이 한정적인 SIP UA에서 암호학적 연산량에 대한 부담이 여전히 존재한다. 제안 기술은 HTTP Digest 인증 기법의 사전 공격 문제를 해결하고 홉 간 보안을 위하여 Diffie-Hellman 키 교환 알고리즘을 사용하여 보안성을 강화하였다. 또한 자원이 충분하지 않은 SIP UA에서 수행해야 하는 Diffie-Hellman 알고리즘의 지수 모듈러 연산을 SIP 서버에게 위임하는 방법을 사용하여 보안성을 강화하였다. 또한 SIP 서버에게 위임하는 방법을 사용하여 제안 기뎁이 기존 기법틀보다 암호학적 연산량에 대한 에너지 소모량이 적다. 제안 기술은 SIP 포준 인증 절차를 크게 수정하지 않고 필요한 인증 파라미터만을 추가하여 간단하게 구현할 수 있기 때문에 이미 널리 사용되고 있는 SIP 환경에 쉽게 적용할 수 있다.

• 정보보호학회논문지
• /
• 제12권3호
• /
• pp.103-118
• /
• 2002

네트워크 상에 전송되는 메시지에 대한 기밀성을 제공하기 위해 암호 시스템의 사용이 점차 증가하고 있으며, 키분배 프로토콜은 안전한 암호 시스템을 구현하는데 가장 필수적인 요소이다. 최근 들어 국내·외에서는 암호화 기능을 제공하는 정보 보안 제품들이 많이 개발되고 있으나, 각 제품에서 사용되는 키 분배 프로토콜의 안전성에 대한 정화한 증명없이 산발적으로 제안되고 있는 실정이다. 따라서, 본 논문에서는 최근에 발표된 표준 키 분배 프로토콜 중 타원 곡선 암호 시스템을 이용하는 ANSI X9.63의 키 분배 프로토콜들에 대해 세션키 설정 과정과 특징을 자세히 분석하고, 이를 기반으로 하여 여러 공격자 모델에 대한 각 프로토콜의 안전성을 분석하고자 한다. 또한, 키 분배 프로토콜의 주요 응용분야의 요구사항을 분석하고 각 분야에 가장 적합한 프로토콜을 제안한다.

• 항공우주정책ㆍ법학회지
• /
• 제17권
• /
• pp.111-132
• /
• 2003

항공운송산업은 그 성격상 국가간 인적 교류의 수단으로서의 중요성이 가장 높다. 항공에 의한 국가간 교류가 이루어지면 이에 따르는 파급효과 및 그 지속성이 타 산업에 비해 월등하기 때문에 항공운송산업에 대한 연구는 국제협력 또는 통합과 관련한 국가 정책은 물론 관련 산업분야의 측면에서 매우 중요하고 가치가 있다. 특히 최근 북한과의 경제교류가 활발해 짐에 따라 북한과의 연결교통망으로서 항공운송의 역할이 더욱 중요해지고 있다. 남북 정상회담이후 급격하게 증가되고 있는 남북간 항공기 운항이 정상적이 아닌 임시 직항로를 설정하여 운영하고 있고, 그 운항회수도 매년 증가하고 있는 점을 고려할때, 남북한 임시 직항로의 운영상 과제를 국제적으로 정한 기준으로 해결하지 아니한 상태에서 지속적으로 운영하는 것은 바람직하지 않다고 본다. 따라서, 본 연구는 남북한 민간항공의 협력이라는 큰 틀위에서 국가적 과업과 효과적인 항공정책의 수립을 위한 기초자료의 제공을 위해 군이통제하는 북한의 민항공에 대한 현황을 분석해 보고, 현재 남북 양국간에 진행중인 "남 북한간 민간항공기에 의한 협력 방안"으로서 "정부의 협력방안과 항공사간 협력방안"을 제시하였고 남북한간에 설정운영중인 "임시 직항로의 운영상 과제"에 대한 개선 대안으로서 임시직항로의 안전확보를 위해서 양국간에 항공관제협정을 체결하여 운영할 것을 제시하였고, 낙후된 기술 요원과 시설에 대한 지원도 하여줄 것을 제시하였다.

• Tribology and Lubricants
• /
• 제33권1호
• /
• pp.9-14
• /
• 2017

This paper presents a rotordynamic analysis and the operation of a power turbine applied to a 250 kW super-critical $CO_2$ cycle. The power turbine consists of a turbine wheel and a shaft supported by two fluid film bearings. We use a tilting pad bearing for the power turbine owing to the high speed operation, and employ copper backing pads to improve the thermal management of the bearing. We conduct a rotordynamic analysis based on the design parameters of the power turbine. The dynamic coefficients of the tilting pad bearings were calculated based on the iso-thermal lubrication theory and turbine wheel was modeled as equivalent inertia. The predicted Cambell diagram showed that there are two critical speeds, namely the conical and bending critical speeds under the rated speed. However, the unbalance response prediction showed that vibration levels are controlled within 10 mm for all speed ranges owing to the high damping ratio of the modes. Additionally, the predicted logarithmic decrement indicates that there is no unstable mode. The power turbine uses compressed air at a temperature of $250^{\circ}C$ in its operation, and we monitor the shaft vibration and temperature of the lubricant during the test. In the steady state, we record a temperature rise of $40^{\circ}C$ between the inlet and outlet lubricant and the measured shaft vibration shows good agreement with the prediction.

• 한국중재학회지:중재연구
• /
• 제14권1호
• /
• pp.273-314
• /
• 2004

There is a belief in the construction industry that the traditional court system may not be an ideal forum to effectively and efficiently resolve construction disputes due to the protracted proceedings and the three tier appeal system resulting in a long delay in the final and conclusive settlement of the dispute, relatively high costs involved, the lack of requisite knowledge and experience in the relevant industry, etc. Hence, they assert that certain alternative dispute resolution ('ADR') methods, such as mediation, conciliation, arbitration or a new system for dispute settlement in the form of any combination thereof should be developed and employed for construction disputes so as to resolve them more promptly and efficiently to the satisfaction of all the disputants concerned. This paper discusses certain merits of such assertions and the need for additional considerations for effective resolution of the construction disputes in light of the complexity of the case, importance of expert witnesses, parties' relationship and non-level playing field of the construction industry and so on. At the same time, however, given the inherent nature of disputes rendering the parties involved in an adversarial position, it would rather be difficult, if not practically impossible, to satisfy all the parties concerned in the dispute. Accordingly, in this study, it is also purported to address the demerits of such assertions by studying the situation from a more balanced perspective, in particular, in relation to the operation of such ADRs. In fact, most of such ADRs as stipulated by special acts, such as the Construction Industry Basic Act of Korea, in the form of mediation or conciliation, have failed to get support from the industry, and as a result, such ADRs are seldom used in practice. Tn contrast, the court system has been greatly improved by implementing a new concentrated review system and establishing several tribunals designed to specialize in the review and resolution of specific types of disputes, including the construction disputes. These improvements of the court system have been warmly received by the industry. Arbitration is another forum for settlement of construction disputes, which has grown and is expected to grow as the most effective ADR with the support from the construction industry. In this regard, the Korean Commercial Arbitration Board ('KCAB') has established a set of internal rules end procedures in operation to efficiently handle construction disputes. Considering the foregoing, this paper addresses the most important elements of the arbitration, i.e., arbitration agreement and arbitral award, primarily focusing on the domestic arbitrations before the KCAB. However, since this parer is prepared for presentation at the construction disputes seminar for the public audience, it is not intended for academic purposes, nor does it delve into any specific acadcmic issues. Likewise, although this paper addresses certain controversial issues by way of introduction, it mainly purports to facilitate the understanding of the general public, including the prospective arbitrators on the KCAB roster without the relevant legal education and background, concerning the importance of the integrity of the arbitration agreement and the arbitral award. In sum, what is purported in this study is simply to note that there are still many outstanding issues with mediation, conciliation and arbitration, as a matter of system, institutional operation or otherwise, for further study and consideration so as to enhance them as effective means for settlement of construction disputes, in replacement of or in conjunction with the court proceeding. For this purpose, it is essential for all the relevant parties, including lawyers, engineers, owners, contractors and social activists aiming to protect consumers' and subcontractors' interests, to conduct joint efforts to study the complicated nature of construction works and to develop effective means for examination and handling of the disputes of a technical nature, including the accumulation of the relevant industrial data. Based on the foregoing, the parties may be in a better position to select the appropriate dispute resolution mechanism, a court proceeding or in its stead, an effective ADR, considering the relevant factors of the subject construction works or the contract structure, such as the bargaining position of the parties, their financial status, confidentiality requirements, technical or commercial complexity of the case at hand, urgency for settlements, etc.

• 한국중재학회지:중재연구
• /
• 제17권1호
• /
• pp.77-95
• /
• 2007

This article focuses on the history and evolution of the US court's attitude towards unilateral arbitration and dispute resolution clauses, but also considers the practical approach of national courts to theses clauses. It goes on to consider some potential pitfalls in the operation of unilateral clauses, which should be borne in mind when developing a strategy for bringing or defending a claim which falls within the scope of a unilateral clause. There can be few objections to the general validity of unilateral arbitration clauses. The principle of party autonomy is the driving force behind international arbitration and, provided it is tolerably clear that the parties intended the arbitration clause to operate unilaterally, courts should be reluctant to interfere with the parties' agreement. There are also no persuasive public policy reasons why such clauses should not be upheld in commercial agreements. In addition to the issue of whether such unilateral clauses are permissible under certain law, it is important to be aware of how they should properly operate in practice, that is, useful guidance on the subject of the proper operation and effect of such clauses where they are intended to be used to enable a party to decide whether, and in what circumstances, a claim should be referred to court or to arbitration.

• Journal of Advanced Research in Ocean Engineering
• /
• 제1권4호
• /
• pp.198-210
• /
• 2015

This paper presents the damage assessment of a free-fall dropped object on the seabed. The damage to a dropped object totally depends on the relationship between the impact energy and the soil strength at the mudline. In this study, unexpected dropping scenarios were first assumed by varying the relevant range of the impact velocity, structure geometry at the moment of impact, and soil strength profile along the penetration depth. Theoretical damage assessments were then undertaken for a free-fall dropping event with a fixed final embedment depth for the structure. This paper also describes the results of a three-dimensional large deformation finite element analysis undertaken for the purpose of validation. The analyses were carried out using the coupled Eulerian-Lagrangian approach, modifying the simple elastic-perfectly plastic Tresca soil model. The validation exercises for each dropping scenario showed good agreement, and the present numerical approach was capable of predicting the behavior of a free-fall dropped object.

• 한국정밀공학회지
• /
• 제21권2호
• /
• pp.203-209
• /
• 2004

Compliant bi-stable mechanism allows two stable states within its operation range staying at one of the local minimum states of the potential energy. Energy storage characteristics of the bi-stable mechanism offer two distinct and repeatable stable states, which require no power input to maintain it at each stable state. This paper suggests an equivalent model of the chevron-type bi-stable microactuator using the equivalent spring stiffness in the rectilinear and the rotational directions. From this model the range of spring stiffness where the bi-stable mechanism can be operated is analyzed and compared with the results of the FEA (Finite Element Analysis) using ANSYS for the buckling analysis, both of which show a good agreement. Based on the analysis, a newly designed chevron-type bi-stable MEMS actuator using hinges is suggested for the latch-up operation. It is found that the experimental response characteristics of around 36V for the bi-stable actuation for the 60$mu extrm{m}$ stroke correspond very well to the results of the equivalent model analysis after the change in cross-sectional area by the fabrication process is taken into account. Together with the resonance frequency experiment where 1760Hz is measured, it is shown that the chevron-type bi-stable MEMS actuator using hinges is applicable to the optical switch as an actuator.