• 디지털융복합연구
• /
• 제20권3호
• /
• pp.377-388
• /
• 2022

의학 분야에서 가파르게 증가하는 인터넷 사용과 다양한 서비스 요구사항을 만족시키기 위한 연구가 활발하게 진행되고 있다. 특히 하나의 광섬유를 통해서 수 테라비트를 운반할 수 있는 광 인터넷은 생존 필요성의 다양한 형태를 만족시키기 위해서는 지능적인 것을 필요로 한다. 본 논문에서는 IP over WDM 네트워크에서 다양한 복구 요구사항을 만족하는 새로운 복구 기법을 제안한다. 이 기법은 복구 서비스를 세 개의 클래스로 구분하고 각 클래스를 위해 서로 다른 우선순위를 가진 공유 복구와 전용의 보고 기법을 활용한다. 또한 이 방법을 지원하는 정보 데이터베이스를 위한 구성 기법이 제안된다. 이 기법은 복구 시간, 블로킹 비율 그리고 자원 활용 측면에서 각 클래스별로 서로 다른 정도의 복구 요구사항을 제공한다. 이 기법을 이용하며, 손실 없이 의학 데이터를 전송할 수 있다.

• 한국통신학회논문지
• /
• 제28권3B호
• /
• pp.200-208
• /
• 2003

본 논문은 제한된 범위의 광 파장 변환기능을 가진 WDM (Wavelength Division Multiplexing) 망에서의 신속한 장애 복구에 적용될 수 있도록 개선된 p-cycle (preconfigured protection cycle) 기법을 제안한다. 개선된 p-cycle 기법은 단방향 멀티캐스팅이나 양방향으로 연결성을 가지지만 비대칭적인 대역폭을 사용하는 광대역 멀티미디어 통신에서 사용되는 단방향 연결을 수용할 수 있도록 수정하였다. 본 논문에서는 개선된 p-cycle 기법을 광 파장 변환기능이 제한적인 WDM 망에서 적용하고 그 결과를 분석하였다. 개선된 p-cycle 알고리즘은 광 파장 변환 기능이 제한적인 WDM망에서 기존의 방안보다 우수한 성능을 보여준다.

• 한국지반신소재학회논문집
• /
• 제21권4호
• /
• pp.79-91
• /
• 2022

최근 폭우, 폭설 등과 같은 이상기후로 인해 도로, 철도 및 단지에 적용된 비탈면의 국부적 파괴 또는 손상 빈도가 점차 증가하고 있다. 초속경 복합매트(Rapid Hardening Composite Mat, RHCM)은 대규모 토공이 불필요하고 수해복구시간을 최소화할 수 있는 장점이 있어 대안으로 고려될 수 있다. RHCM은 대표적인 비탈면 보호공법인 숏크리트 공법 및 식생공 공법에 비해 중장비 설비가 불필요하고 유지관리가 용이하며, 기존 Geosynthetic Concrete Composite Mat(GCCM)에 비해 경화시간이 짧아 긴급복구가 가능하다는 장점이 있다. 따라서, 본 연구에서는 실내시험을 통해 RHCM의 강도 및 내구성을 측정하고 GCCM과 비교·분석하였다. 실내시험 결과 RHCM의 강도는 기존 GCCM에 비해 약 51% 높은 것으로 나타났으며, 내구성 또한 69% 높은 것으로 나타났다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 A
• /
• pp.51-54
• /
• 1992

Protection and control systems play a prominent part in avoiding power delivery interruptions and help to get a fast and secure restoration when a failure occurs. In order to meet the higher functional requirements on modern power system, protection speed, selectivity, sensitivity, dependability, and security are essential to ensure reliability. These functions on be satisfied by taking advantage of microprocessor and communication technologies, and digital protection relays (systems) have been developed and applied to real power system enhancing reliability and saving money. It is necessary to have a tool to analyze the functions and algorithms of digital relays for installing them to power system. The purpose of this study is to develop a digital relay simulation program to estimate digital relay performances during system faults. Components of digital protective relay including analog filter, sampling unit, digital filter, and relay logic are modeled in this program.

• 전기학회논문지
• /
• 제62권6호
• /
• pp.744-749
• /
• 2013

The protection switching technology is widely adopted in the fiber-optical transmission equipments based on TDM(Time Division Multiplexing), such as PDH, SDH/SONET. A variety of protection switching algorithms for Ethernet networks and the progress of standardization are summarized in the document. There are several kinds of protection switching algorithms for Ethernet networks, such as STP, RSTP, MSTP and etc. However, since Ethernet signal move through detour route, it causes much time to recover. Accordingly, it is difficult to secure a usability of Ethernet networks and QOS(Quality of Service). Also, if the protection switching protocol standardized by IEEE and ITU-T is used, it remains a inherent network switching time for protection. Therefore, a specific protection switching algorithm for Ethernet are needed for seamless and stable operation of Ethernet networks service for Distribution Automation System(DAS). A reliable protection algorithm with no switching delay time is very important to implement Self-healing service for DAS. This study of FPGA based protection switching algorithm for Ethernet networks shows that in case of faults occurrence on distribution power network, immediate fault isolation and restoration are conducted through interaction with distribution equipments using P2P(Peer to Peer) communication for protection coordination. It is concluded that FPGA based protection switching algorithm for Ethernet networks available 0ms switching time is crucial technology to secure reliability of DAS.

• 한국환경복원기술학회지
• /
• 제17권4호
• /
• pp.43-56
• /
• 2014

In this study, ecological investigation was performed on Yong-neup, Daeam-san for 5 times. This area is considered DMZ zone located between Yanggu-gun and Inje-gun, Gangwon-do, where has been recognized highly valuable for ecological preservation. As a result, Sphagnum and hydrophobic vegetation were found in Little Yong-neup, revealing its characteristics of high moor, where as no Sphagnum were found in Baby Yong-neup. Thereby, the carnification has been investigated in both Little Yong-neup and Baby Yong-neup. A main cause of damage was associated with the creation of stating rink and increases of visitors. The damages of vegetation in Little Yong-neup and Baby Yong-neup have been intensified by road construction or uses of groundwater while relocating military troops to upper stream of Little Yong-neup and Baby Yong-neup, further causing the damages of water circulation system and soil erosion. These artificial factors have caused the carnification of wetland protection areas including Little Yong-neup. The terrestrial vegetations, such as Plantago asiatica, Geranium Koreanum and Artemisia feddei have increased compared to current survey conducted by the Ministry of Environment. 5 endangered species, such as Lychnis wilfordii and Trientalis europaea and 5 other introduced species, such as Aster pilosus and Taraxacum officinale were found. 10 different species of mammal and 2 species of amphibian were investigated; and in addition to this, a original form of Sphagnum fens, the remaining wetland was found. Therefore, this study is to identify the causes of damages in Little Yong-neup and Baby Yong-neup through their ecological survey and accordingly proposing a direction for ecological restoration through the improvement of water circulation system, creation of habitats for plant and animal, restoration of vegetation through eco-friendly materials and indigeneity, relocation of the current military troops, securing of structural stability.

• 한국방재학회 논문집
• /
• 제9권5호
• /
• pp.87-92
• /
• 2009

현재까지의 치수대책이나 복구대책은 대부분 당해 연도의 지역별 피해액만을 기준으로 이루어지고 있다. 그러나 지역의 홍수 발생빈도와 홍수피해액 관계를 분석하면 지역의 홍수피해특성을 고려한 보다 합리적인 치수대책을 마련할 수 있다. 본 연구에서는 점빈도 분석을 이용하여 과거 38년('70~'07)간의 전국 시군구별 홍수피해자료를 이용하여 무차원 홍수피해 발생빈도와 피해액간의 상관관계를 분석하였다. 분석결과를 바탕으로 사분면적 해석방법을 도입하여 전국 시군구의 홍수피해 유형을 다빈도-대피해 지역, 다빈도-소피해 지역, 소빈도-대피해 지역, 소빈도-소피해 지역이라는 네 가지 유형으로 구분하였다. 본 연구의 분석결과를 활용하면 시군구별로 홍수피해액별 발생빈도와 발생빈도별 홍수피해액을 손쉽게 비교할 수 있기 때문에 지역의 치수방어년을 설정하는 데에도 많은 도움이 될 수 있다. 또한, 발생빈도별 홍수피해액을 산정할 수 있기 때문에 치수사업의 효과를 분석하거나 예측하기 위한 기초자료로도 충분히 활용할 수 있을 것이다.

• 한국환경복원기술학회지
• /
• 제13권3호
• /
• pp.73-83
• /
• 2010

A technology using continuous fiber soil reinforcement system for the creation of ecological restoration in a damaged area has been developed and introduced. The continuous fiber soil reinforcement system (Geofiber system) is an environmentally friendly slope protection technique that continuous fiber soil reinforced layers are constructed with green plantation on cut slope. The characteristics of this system in terms of the strength and hydraulic performance, and the vegetation were investigated in this study. The main objectives of this comparative study was to quantify the potential contribution of geofiber system for the revegetation on the cut slope in a damaged area. A Geofiber system was constructed to reinforce the lower layer of slopes and revegetation methods including wood chips were carried out on the upper layer by machineries. The results of monitoring during 3 years on cut slopes were as follows : 1) All the quadrat existed in the proper range for vegetation. 2) Species richness was 4.4 (site-1) and 18.5 (site-2) respectively. 3) The averaged coverage rates of quadrats was 90%. It is remarkable that the continuous fiber soil reinforcement system would be capable of applying to a damaged area and also would serve maintaining a healthier environment for floras. However, it behooves to continue monitoring on succession of vegetation for ecological restoration.

• 한국환경복원기술학회지
• /
• 제9권6호
• /
• pp.162-167
• /
• 2006

The urban stream includes the channel and sandbars. The sandbar plays a key role in the riparian ecosystem. For birds and insects the sandbar offers a small strip of habitat and fish and other fauna feed in the boundary of sandbar where eddies occur. So, it is important habitat and source for the flow of energy, matter and organisms through the landscape and act as ecotone between the terrestrial and stream corridors. However, the sandbar changes continuously by the natural process. Thus, it is necessary to measure the shape and area of the sandbar accurately for the efficient urban stream management for the amenity of urban residents and stream protection. The study site is Yangjae Stream where the first natural-style urban stream restoration projected was impelemented by the support of Ministry of Education in Korea. The measurement was taken by the beacon Differential Global Positioning System (DGPS) and the data were stored and analyzed using ArcView Geographic Information System (GIS) program. Therefore, the purpose of this study is to measure the change of sandbars in the urban stream after concentrated stormwater during summer.

• 한국환경복원기술학회지
• /
• 제23권4호
• /
• pp.59-67
• /
• 2020

In this study, the effects of windbreak fences composed of natural vegetation on one-year-old seedlings were analyzed to develop restoration methods for an endangered subalpine species, the dwarf Siberian pine (Pinus pumila (Pall.) Regel). One-year-old seedlings were planted in 2016 by sowing seeds that had been collected from the Daecheongbong area on Mt. Seoraksan, South Korea, in 2014. The area near Daecheongbong was selected as the experimental site, and treatment and control plots (2m×2m) were installed at the site. To analyze the effects of wind protection, windbreak fences were constructed in the treatment plots using hairy Korean rhododendrons (Rhododendron mucronulatum Turcz. var. ciliatum Nakai) from the surrounding area and weather stations were installed to investigate atmospheric temperature, humidity, and wind speed. In all control plots without windbreak fences, dwarf Siberian pine seedlings were killed by strong winds seven months after planting. In contrast, the average survival rate of the seedlings in treatment plots was 96.7% after seven months, 64.2% after two years, and 45% after three years, with most (85.3%) of the seedlings showing good initial root establishment. Accordingly, windbreak fences composed of natural vegetation are suitable for promoting the early establishment of seedlings in the restoration of dwarf Siberian pine stands.