• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.1
• /
• pp.32-39
• /
• 2011

The purpose of VDR capsule is to maintain a stored information securely and retrievably in the extreme environment like voyage incident. This study shows the modellings, the analyses and the experiments of the survivability test of penetration, high and low temperature fire. The capsule housing is used to protect capsule against penetration and the influences of its thickness are studied by the modelling and analysis of penetration using LS-DYNA. The phase change material and thermal insulation material are used to protect capsule against high and low temperature fire test. The thermal characteristics of various volume ratios of phase change material to thermal insulation material were conducted. Also the tests were conducted to confirm the structural and thermal reliability.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.07a
• /
• pp.208-211
• /
• 2010

2012년 지상파 방송은 아날로그 송출을 종료하고 디지털 방송으로 전환된다. 이렇게 전환되는 지상파 디지털 방송은 무료로 누구나 시청할 수 있는 보편적 서비스를 지향하기 때문에, 케이블TV, 위성TV, IPTV 등의 다른 매체와는 달리 기술적 보호조치 없이 방송되고 있다. 또한 DTV 방송프로그램은 원본과 똑같은 화질로 개인이 쉽게 저장할 수 있고 인터넷을 통하여 누구나 쉽게 접근이 가능하기 때문에, DTV 방송프로그램의 무단복제와 인터넷을 통한 불법재배포는 큰 문제점으로 대두되고 있다. 이러한 불법 대량배포는 방송프로그램의 저작권을 심각히 침해할 뿐만 아니라, 방송사의 고품질의 방송프로그램을 제작환경을 더욱 열악하게 만들고 있다. 또한 일반 사용자는 인식하지 못하는 사이에 인터넷을 통해 불법 콘텐츠를 사용하게 되는 악순환에 빠지게 된다. 이에 본 논문은 KBS에서 추진하고 있는 여러 콘텐츠 보호 기술들을 하나의 보호 고리로 연결하는 KBS 보호기술 체계를 소개하고자 한다. 이를 위하여 KBS는 아래의 3가지 보호 기술을 개발하여 체계적으로 연결하여 적용하고 있다. 첫째, 프로그램의 저작권과 배포 정보를 나타내는 프로그램 보호신호(PPI, Program Protection Information)와 워터마크를 방송 신호에 삽입하여 수신기에서의 프로그램 보호를 추진한다, 둘째, 인터넷 OSP(Online Service Provider)와의 제휴를 통하여 콘텐츠 필터링 기술을 도입하여 프로그램 불법 업로드, 다운로드를 방지한다. 셋째, KBS 저작물 인터넷 모니터링 시스템을 개발하여 인터넷 상의 불법 프로그램 배포정보를 획득하여 불법배포가 진행되는 사이트에 보호를 요청한다.

• Journal of Chest Surgery
• /
• v.41 no.5
• /
• pp.671-674
• /
• 2008

Jejunum and fasciocutaneous and myocutaneous flaps are theoretically recommended as esophageal substitutes in reconstruction of the esophagus after several occurrences of failed reconstruction. However, other esophageal substitutes should also be considered. Secondary esophageal reconstruction was successfully performed on a 24-year-old woman who had a history of cervical, thoracic, and abdominal operations and esophageal stricture secondary to several failed reconstructions for esophageal atresia and tracheo-esophageal fistula 21 years prior. The esophageal reconstruction was done subcutaneously by end-to-side anastomosis at the left cervical area using a deformed stomach graft. The patient was discharged with the ability to consume a regular diet after the operation.

• Journal of Sensor Science and Technology
• /
• v.7 no.5
• /
• pp.313-318
• /
• 1998

The thermal annealing, reusability and fading characteristics of the highly sensitive LiF:Mg,Cu,P TLDs are investigated. Thermoluminescent sensitivity of the fabricated LiF:Mg,Cu,P TLD is 25.3 times higher than the commercial dosimeter TLD-700(Harshaw Chemical Co.). The main dosimetric peak shows no fading for 1 month at room temperature and 50% for 7 days at $100^{\circ}C$. The thermal annealing characteristics is examined in the temperature range from $260^{\circ}C$ to $320^{\circ}C$. For annealing the TLD at $280^{\circ}C$ for 10 minutes, TLDs can be reusable by recovering the initial sensitivity.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.4
• /
• pp.289-295
• /
• 2008

The disposal of constructive waste is emerging as a national and social issue and the recycled powder generated by the production of reproductive aggregate is all being abolished or buried Analysis on the harmful effect of recycled powder indicated that because it contained massive cytotoxicity, it could derive secondary pollution to soil and subterranean water. This study set on an idea that one way to recycle recycled powder was to use it as a compound of concrete. In order to study that prospect, recycled powder, instead of cement, was mixed and a comparative analysis was conducted on the mechanical properties and workability. From experimental results, it was judged that application of recycled powder of cement replacement ratio below 20% was available with chemical admixtures. Also application of recycled powder was available to high strength concrete.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.6
• /
• pp.758-765
• /
• 2016

In this study, wave damping due to a permeable bed of finite depth was modelled using a complementary mild-slope equation for stream function. The energy dissipating term in the mild-slope equation was presented in terms of stream function. In order to prevent re-reflection of reflected waves along the outer boundary, a delta-function-shaped source function was derived to generate a wave in a computational domain. Numerical experiments were conducted to measure the reflection coefficient of waves over a planar slope for various incident wave periods. The numerical result of the proposed model was compared with that of an integral equation method, showing good agreement in general. However, the proposed model showed relatively higher transmission rate for the larger permeability and the longer wavelength.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.4
• /
• pp.308-323
• /
• 2009

This review paper serves to describe the composition and activity of biological activated carbon (BAC) biofilm which is considered as a progressive process for water treatment. As well as several physical-chemical, biochemical and microbiological analysis methods for characterizing the composition and activity of BAC biofilm, the ability of the biofilm to remove and biodegrade organic matters and pollutants related to other water treatment processes such as pre-ozonation will be reviewed. In this paper, conversion of GAC into BAC, removal mechanism of pollutants, characteristics and affecting factors of BAC biofilm, and modeling of BAC are described in detail. In addition, strategies to control the growth of the BAC biofilm, such as varying the nutrient loading rate, altering the frequency of BAC filter backwashing and applying oxidative disinfection, will be dwelled on related to their respective process control challenges.

• Journal of Conservation Science
• /
• v.28 no.3
• /
• pp.247-256
• /
• 2012

Amber has been used as gemstones and artifacts from the period of the Three Kingdoms or earlier, which are discovered in the process of excavation now. It is, however, very difficult to discuss the importing route and circulation of amber because there are no informations available on the provenance. In this study, we acquired the IR spectra of ambers originating from 5 different locations. We also monitored the change of characteristic IR peaks by artificially aging the ambers under heat, light and heat with oxygen, respectively. As the aging proceeded, the intensity of C=O band and O-H band increased, however, the bands related with C=C bond decreased. There needed some modifications in the discerning scheme because some peak disappeared with aging; yet, it was still possible to discern different ambers largely. Therefore, it is expected that the scheme can be used practically by appraising its applicability to the real amber relics excavated.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.12
• /
• pp.913-917
• /
• 2009

Flash memories have asymmetric I/O costs for read and write in terms of latency and energy consumption. However, the ratio of these costs is dependent on the type of storage. Moreover, it is becoming more common to use two flash memories on a system as an internal memory and an external memory card. For this reason, buffer cache replacement algorithms should consider I/O costs of device as well as possibility of reference. This paper presents WWCLOCK(Write-Weighted CLOCK) algorithm which directly uses I/O costs of devices along with recency and frequency of cache blocks to selecting a victim to evict from the buffer cache. WWCLOCK can be used for wide range of storage devices with different I/O cost and for systems that are using two or more memory devices at the same time. In addition to this, it has low time and space complexity comparable to CLOCK algorithm. Trace-driven simulations show that the proposed algorithm reduces the total I/O time compared with LRU by 36.2% on average.

• Journal of the Korean Society for information Management
• /
• v.19 no.4
• /
• pp.298-319
• /
• 2002

The Semantic Web is a new technology that attempts to achieve effective retrieval, automation, integration, and reuse of web resources by constructing knowledge bases that are composed of machine-readable definitions and associations of resources that express the relationships among them. To have this kind of Semantic Web in place, it is necessary to have the following infrastructures: capability to assign unchangeable and unique identifier (URI) to each resource, adoption of XML namespace concept to prevent collision of element and attribute names defined by various institutions, widespread use of RDF to describe resources so that diverse metadata can be interoperable, use of RDF schema to define the meaning of metadata elements and the relationships among them, adoption of DAML+OIL that is built upon RDF(S) to increase reasoning capability and expressive power, and finally adoption of OWL that is built upon DAML+OIL by removing unnecessary constructors and adding new ones based on experience of using DAML+OIL. The purpose of this study is to describe the central concepts and technologies related to the Semantic Web and to discuss the benefits of metadata interoperability based on XML/RDF schemas and the potential applications of diverse ontologies.