• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.108-115
• /
• 2011

용수공급 계획의 수립이나 수자원시설물 운영에서 주어진 목적의 달성여부를 판단하는 기준은 사회적 합의를 바탕으로 한 공개념으로 작용하기 때문에 기준 적용은 매우 신중하게 다루어져야 한다. 이런 기준들은 신규용수공급시설 설계나 기존시설의 경우 이행도를 평가하는 척도가 되며 경제성이나 대안을 결정하는데 이용된다. 또한 이런 기준들은 국가 수자원 정책의 지표가 될 뿐만 아니라 물 공급 서비스를 받는 사람들에게 최소 필요로 하는 물을 어느 수준으로 얼마를 어떻게 공급할 것인가를 약속하는 의미를 갖는다. 이를 위해 우선 검토하여야 할 사항은 용수공급신뢰도 조사를 위한 기본체계를 제공하고 현재 신뢰도가 어떻게 정의되었으며 물 공급관리지표에 맞추어 예상되는 물 수요의 증가를 언제 어떻게 맞출 것인가라는 측면에서 신규시설물을 계획하면서 공급신뢰도에 의한 계획공급량(목표공급량)을 정하였다. 물을 공급받는 수요자는 공급에 대한 신뢰도가 높은 상태를 원하며 자신이 원하는 물을 아무런 장애없이 지속적으로 공급될 수 있는 조건을 전제로 물 공급계약을 체결한다. 이와 같은 신뢰도가 늘 엄격히 지켜지는 것은 아니나 현대 사회에서도 수요와 공급관계에서 지켜져야 할 기준으로 인식되고 있다. 아울러 수자원 기술자들에게 는 최적으로 달성해야할 업무목표가 된다. 그러나 제한된 정보를 이용하여 용수공급의 신뢰도를 정하게 되며 설계치를 초과하는 수문사상의 불확실성 및 수리구조물의 불안정 등으로 물 공급의 위험도는 항시 발생할 수 있다. 또한 인구증가나 새로운 산업입지에 의한 물 수요의 증가는 기존 시설물의 용량을 초과하여 물 공급의 신뢰도를 악화시킬 수 있다. 가장 널리 이용되고 있는 공급신뢰도 개념은 목표한 용수공급량 혹은 수요량을 충족시키느냐 못하느냐의 정도를 발생빈도 확률로 나타내는 것이다. 그러나 신뢰도의 적용에 대한 기준은 국내뿐만 아니라 외국에서도 종종 논란거리가 되고 있다. 또한 한 국가 내에서나 수자원을 개발하는 기관 내에서도 동일 목적의 사업별로 적용기준이 천차만별이다. 본 연구에서는 국내 외 이수안전도에 대한 정의와 적용사례를 분석하고 각각의 기준이나 지표의 장단점을 비교 평가하고자한다. 아울러 도출된 문제점을 바탕으로 개선방향을 제시하고자 하며, 궁극적으로 국내의 이수안전도 기준설정에 대한 종합적 의견을 제시 하고자 한다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.304-304
• /
• 2011

열필라멘트 화학 기상 증착 공정(HWCVD, hot wire chemical deposition)은 낮은 기판 온도에서 다결정 실리콘 박막을 빠른 속도로 증착할 수 있는 방법이다. 이는 후처리가 없어도 전기적 특성이 우수한 박막을 저온에서 얻을 수 있기 때문에 녹는점이 낮은 기판에 증착을 할 수 있으며 공정비용 절감 효과가 있다. 이러한 박막 증착 공정 중 기상 핵생성에 의해 나노 입자가 생성되며, 새로운 관점에서는 그 농도와 크기가 박막 성장에 중요한 변수로 작용한다. 따라서 공정조건의 변화에 따라 생성되는 나노 입자의 크기 분포를 실시간으로 분석하여 박막 형성의 최적 조건을 찾는 연구가 필요하다. 하지만 이러한 입자 발생 특성에 관한 연구는 기존에 밝혀진 반응 메커니즘으로 인해 수치해석적 연구는 체계적으로 진행되었으나 실험적 연구의 경우 적합한 측정장비의 부재로 인해 제한이 있었다. 따라서 본 연구에서는 저압에서 실시간으로 나노입자 분포를 측정할 수 있는 PBMS (particle beam mass spectrometer)를 이용하여 열필라멘트 화학 기상 증착 공정 중 발생하는 입자의 존재를 확인하고 특성을 분석하였다. 실리콘 나노 입자의 측정은 PBMS 장비의 전단 부분을 HWCVD 배기 라인에 연결하여 진행하였으며 반응기 내 샘플링 위치, 필라멘트 온도, 챔버 압력, 작동기체의 비율을 변수로 하여 진행하였다. 그 결과 실리콘 나노 입자는 양 또는 음의 극성을 가진 하전된 상태임을 확인 하였고, 측정 조건에 따라 일부 단일 극성으로 존재하였다. 한편, 필라멘트 온도가 증가할수록 하전된 나노입자의 최빈값은 감소하였다. 또한 반응 가스인 SiH4 농도가 증가할수록 최빈값은 농도에 비례하여 증가하였다. 이런 결과는 기존 HWCVD 실험에서 투과 전자 현미경(TEM)을 이용하여 분석한 실리콘 나노 입자의 크기 분포 결과와 경향이 일치함을 확인하였다. 본 연구를 통하여 확인된 하전된 나노 입자의 존재를 실험적으로 확인하였으며 추후 지속적 연구에 의해 이러한 하전된 나노 입자가 박막 형성에 기여 하는 것을 규명하고 박막 형성 조건을 최적화하는데 중요한 역할을 할 것을 기대할 수 있다.

• Journal of Internet Computing and Services
• /
• v.16 no.5
• /
• pp.1-9
• /
• 2015

As attacks in cyber space become advanced and complex, monotonous defense approach of one-one matching manner between attack and defense may be limited to defend them. More efficient defense method is required. This paper proposes multi layers security scheme that can support to defend assets against diverse cyber attacks in systematical and adaptive. We model multi layers security scheme based on Defense Zone including several defense layers and also discuss essential technical elements necessary to realize multi layers security scheme such as cyber threats analysis and automated assignment of defense techniques. Also effects of multi layers security scheme and its applicability are explained. In future, for embodiment of multi layers security scheme, researches about detailed architecture design for Defense Zone, automated method to select the best defense technique against attack and modeling normal state of asset for attack detection are needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.485-488
• /
• 2016

The level of domestic greenhouse complex environmental control technology is a hardware-oriented automation steps that mechanically control the environments of greenhouse, such as temperature, humidity and $CO_2$ through the technology of cultivation and consulting experts. This automation brings simple effects such as labor saving. However, in order to substantially improve the output and quality of agricultural products, it is essential to track the growth and physiological condition of the plant and accordingly control the environments of greenhouse through a software-based complex environmental control technology for controlling the optimum environment in real time. Therefore, this paper is a part of general methods on the greenhouse complex environmental control technology. and presents a horticulture production forecasting methods using artificial neural networks through the analysis of big data systems of smart farm performed in our country and artificial neural network technology trends.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.5D
• /
• pp.477-483
• /
• 2010

The existing mass transport system, with its limited capacity and the saturated road networks, has given cause for a new means of transport to be developed, and strong demands for such new means of transport are observed more than ever. However, the traffic authority is seeking a new transport system that focuses more on LRT(Light Rail Transit), a downsized version of the existing urban railroad, rather than one that is appropriate to solve the traffic problems. Moreover, local governments are experiencing difficulties in planning their own mass transportation(bus or urban railroad) as they have no specified criteria for selecting a mass transport system. Accordingly, there has been an increasingly loud voice that calls for criteria to determine which mass transport system befits each transportation corridor. This paper develops a mass-transport demand forecasting model based on the GIS Buffering analysis of each transportation corridor in the city, sets up the capacity for each mass transport system and presents the criteria for selecting an optimal mass transport system for each transportation corridor. It also presents a methodology that identifies necessary and sufficient conditions for selection and evaluation, since it is most important to select the optimal mass-transport system that can meet the demand by each mass-transportation corridor.

• Korean Journal of Construction Engineering and Management
• /
• v.9 no.2
• /
• pp.159-169
• /
• 2008

Recently, domestic construction projects Have become more high-rised, bigger, sophisticated, so necessity of logistics and progress management through application of various management theories has also been increased and development of IT technologies like RFID can help to improve management method, although the existing logistics and progress management studies are applied only to single progress or important material. It is a basic research for integrated framework for logistics and progress management. An analysis on the characteristics of RFID tech was performed for major materials or components of each work item in office building projects. This paper will make foundation of integrated framework for logistics and progress management in construction project, utilizing RFID technology by analysing materials type like materials which can be chased and measured, materials which can be chased and measured by certain methodologies, materials which can be chased and measured by future technologies, materials which are difficult to be chased and measured. So we can effectively control logistics and progress management, appling the optimum RFID technology to each construction project, and we need to study out solution in order to overcome RFID technology limitation through development of specification counterproposal about delicate materials of the RFID technology application.

• Ecology and Resilient Infrastructure
• /
• v.10 no.3
• /
• pp.73-84
• /
• 2023

The objective of this study was to evaluate biodiversity and natural habitat environment of freshwater ecosystem. Our aim was therefore to produce a set of biodiversity and habitat indicators based on multi-parameters of water quality and biodiversity by analyzing the characteristics of the results by indicators. We selected four indicators a) anthropogenic disturbance, b) habitat diversity, c) biodiversity, d) ecosystem structure. The fishes cohabiting with Brachymystax lenok tsinlingensis were Rhynchocypris kumgangensis and Zacco koreanus. As a result of the anthropogenic disturbance evaluation, it was analyzed that vegetation embankment showed a more stable environment in the tributary than the main stream, and other disturbance was not confirmed As a result of the habitat diversity evaluation, it was analyzed that habitat evaluation index showed a high score of 200 more on average, showing an optimal habitat condition. As a result of the biodiversity evaluation, it was analyzed as a clean habitat condition with a high proportion of sensitive species, abundant dissolved oxygen, and little pollutants. As a results of the ecosystem structure, the ecological health condition metrics and appearance of endangered species showed large score deviation, but it was analyzed that the stream ecosystem health was generally excellent. There was a slight correlation between the habitat environment and the results of the nature habitat evaluation according to the appearance of the B. lenok tsinlingensis.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.4
• /
• pp.17-26
• /
• 2023

To consider the risk of damage and fracture of P.C strands, the existing post-maintenance system alone has the limitations, hence it is necessary to quantitatively evaluate and predict the deterioration, durability and safety of facilities and establish a reasonable maintenance system considering the asset value of facilities. Therefore, it is worth considering a preventive maintenance plan that allows proactive measures to be taken before a major defect occurs in the temporary anchor. This study devised a preventive over tension method, reviewed its effectiveness through design and field tests, by calculating the resistance factors by performing a reliability-based optimization design. At this time, the over tension anchor method was evaluated using the ratio of the residual tension force after the fracture of P.C strands to the effective tension force before the fracture of P.C strand, followed by the resistance factor calculated by the optimal solution for each random variables using Excel solver and applying it to the limit state equations. As a result of the study, if the over tension ratio is 125% to 130%, the remaining strands showed a high resistance effect even after the fracture of P.C strand. As a result of the optimization design, it was found that it is appropriate to apply the load factor (γ) of 1.25, and the resistance factors of Φ₁, Φ₂, Φ₃ as 0.7, 0.5, 0.6.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.6
• /
• pp.63-70
• /
• 2011

A bicycle is different from vehicles in the structure that a rider is fully exposed to the surrounding environment. Therefore, it needs to make use of prior information about local weather, air quality, trail road condition. Moreover, since it depends on human power for moving, it should acquire route property such as hill slope, winding, and road surface to improve its efficiency in everyday use. Recent mobile applications which are to be used during bicycle riding let us aware of the necessity of development of intelligent bicycles. This study aims to develop a riding state (up-hill, down-hill, accelerating, braking) recognition algorithm using a low-power wrist watch type embedded system which has 3-axis accelerometer and wireless communication capability. The developed algorithm was applied to 19 experimental riding data and showed more than 95% of correct recognition over 83.3% of the total dataset. The altitude and temperature sensor also in the embedded system mounted on the bicycle is being used to improve the accuracy of the algorithm. The developed riding state recognition algorithm is expected to be a platform technology for intelligent bicycle interface system.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.6
• /
• pp.13-24
• /
• 2008

The multi robot operation technique has emerged as one of the most important research subjects that focus on minimizing redundancy in space exploration and maximizing the efficiency of operation. For an efficient operation of the multi robot systems, the movement of each Single robot in the multi robot systems should be properly observed and controlled. This paper suggests Multi Robot Management System to minimize redundancy in space exploration by assigning exploration space to each robot efficiently to take advantage of the RFID. Also, this paper has suggested fault tolerance technique that detects disable Single robot and substitute it by activated Single robot in order to ensure overall exploration and improve efficiency of exploration. Proposed system overcomes previous fault that it is difficult for central server to detect exact position of robot by using RFID system and Home Robot. Designated Home robot manages each Single robot efficiently and assigns the best suited space to Single robot by using RFID Tag Information. Proposed multi robot management system uses RFID for space assignment, Localization and Mapping efficiently and not only maximizes the efficiency of operation, but also ensures reliability by supporting fault-tolerance, compared with Single robot system. Also, through simulation, this paper proves efficiency of spending time and redundancy rates between multi robot management applied by proposed system and not applied by proposed system.