• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.62-72
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• 2007

Mobile Virtual Private Network (MVPN) provides VPN services without geographical restriction to mobile workers using mobile devices. Coexistence of Mobile IP (MIP) protocol for mobility and IPsec-based VPN technology are necessary in order to provide continuous VPN service to mobile users. However, Problems like registration failure or frequent IPsec tunnel re-negotiation occur when IPsec-based VPN Gateway (GW) and MIP are used together. In order to solve these problems, IETF proposes a mechanism which uses external home agent (x-HA) located external to the corporate VPN GW. In addition, based on the IETF proposal, a mechanism that assigns x-HA dynamically in the networks where MN is currently located was also proposed with the purpose to reduce handover latency as well as end-to-end delay. However, this mechanism has problems such as exposure of a session key for dynamic Mobility Security Association (MSA) or a long latency in case of the handover between different networks. In this paper, we propose a new MVPN protocol in order to minimize handover latency, enhance the security in key exchange, and to reduce data losses cause by handover. Through a course of simulation, the performance of proposed protocol is compared with the existing mechanism.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.157-167
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• 2016

Detached residential housing areas are located in the west part of Pangyo City. Seven areas of them are designated for the displaced residents from their original homes by the city development, in which commercial use on the first floor is permitted. The District Plan for the areas were establishes, and one of its main goals is to secure privately owned public spaces (POPS). This research conducted a post enumeration survey on the POPS on the blocks in the seven areas, which blocks contain inner corridors between two rows of housing units. Analytical review of the survey result reveals that (1) POPS facing roads are mainly being used as parking lots or expansion-spaces for the commercial use on the first floor, (2) inner POPS forming corridors are being neglected and otherwise being used as storage areas or outdoor sub-kitchen spaces, and (3) no consideration has been taken for the continuity of the sloped corridors. Regardless of a few good practices in terms of air circulation and lighting, the POPS in the blocks prove to be limited in following the plan's original design intentions and principles.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.274-283
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• 2015

The reservoir shores seem to be vulnerable to biological invasion. The purpose of this research was to find out the floristic composition of alien plants and their relationship between environmental factors on reservoir shorelines in Korea. We investigated flora of alien plants and environmental factors of geomorphology, hydrology, water quality and soil on the shoreline of a total of 35 reservoirs with different water level managements. There were 56 species of alien plants, which was 15% of the total plant species identified in the study of reservoirs. A total of 57% of these alien species were the species which were introduced shortly after opening the port from 1876 to 1921 in Korea. More than 80% of the alien plants on the reservoir shores originated from America and Europe. The current distribution of Ambrosia trifida and Paspalum distichum were restricted in the central part and the southern region of the Korean Peninsula, respectively. The water level fluctuation, flood frequency at the median water level, water pollution index, coverage of rock exposure and mean degree of shoreline slope were determined as important environmental factors that have an effect on the characteristics of shoreline alien flora. Our results suggest that the reservoir shore was in danger of being invaded by alien plants due to the water level management and other human disturbances. For effective conservation of the reservoir ecosystem, periodic monitoring systems are required for the early detection of alien species on the reservoir shore.

• Analytical Science and Technology
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• v.27 no.2
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• pp.108-113
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• 2014

The harmful materials as volatile organic compounds (VOCS) that is easy for gas to be changed from liquid on ambient temperature, those should be controlled by Korea Chemicals Management Association. The VOCs samples should be collected directly in place so that those could be analyzed. Generally but it couldn't avoid to have the risk of analyst. Moreover, if there is the place limited to entrance, it is impossible to collect directly and measure. Owing to such problem, it tried to be solved by open path FT-IR spectrometer that could be studied on the combustion gases within long path and VOCs samples were tried to measure to large volume by remote and real time. Firstly, it was to investigate optimized measured length between the system and benzene sample of VOCs. As result, The optimized measured length was confirmed with 15 meter length and the qualitative analysis could be measured on seven VOC samples. The calibration curve as quantitative analysis of benzene samples could be worked. On the basis of the result, the system as remote monitor could show to have potentiality.

• The Journal of the Korean life insurance medical association
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• v.22
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• pp.99-120
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• 2003

그 동안 지속적인 경제성장을 바탕으로 한국의 생명보험산업은 양적으로 성장하였다. 그러나 내면을 살펴보면 외형을 떠받칠 만큼 내실있게 성장했는지에 대해서는 많으 의구심을 갖게 한다. 현실적으로 경제성장을 바탕으로 한 외형성장은 한계를 맞을 수 밖에 없으며, 이제는 질적인 내실을 기하기 위해 그 동안 소홀히 했던 보함산업의 전반의 체질개선이 필요하다. IMF이후 경영이 부실한 보험사들이 퇴출되면서 전면적인 개편이 이루어졌고, 또한 보험사 내부에서도 전반적인 개혁의 필요성을 인식하여 여러 방면으로 방안을 구체화하고 있다. 본 논문은 이러한 상황하에서 생명보험산업의 기존 문제점 개선방안의 일환으로, 보험산업의 가장 핵심분야라 할 수 있는 언더라이팅 분야의 국내현황을 살펴보면서 보험선진국의 제도 및 운영현황과 비교 분석하여 부문별 문제점을 도출하고, 그에 따른 개선방안을 제안하게 되었으며, 본 논문에서 제시된 개선방안을 요약해 보면 다음과 같다. 첫째, 언더라이팅을 신속 정확하게 수행하고 도덕적 위험을 배제하기 위하여 개선된 정보교환시스템 제도를 구축해야 하며, 사정자료의 수집업무를 전문기관에게 아웃소싱함으로써 비용절감을 기하여야 한다. 이와 아울러 모집인의 전문성을 제고시켜 보험계약 청약서와 모집인 보고서가 정확하게 작성되도록 하고 언더라이팅 실적과 연계한 인센티브제도에 의하여 모집수당이 지급되도록 하여 언더라이팅이 효과적으로 수행되도록해야 할 것이다. 둘째, 언더라이팅기법의 선진화를 기함으로써 위험에 상응하는 보험료를 부가하여 위험에 노출되어 있는 가망고객의 보험가입율을 높이고, 보험사고 발생시 실질적인 보험혜택을 누리도록 하여야 한다. 이를 위한 실천방안으로 의적 직업적 재정적 언더라이팅 선진기법을 도입하여 각 부문의 역량을 강화해야 할 것이다. 특히 제도적으로 개인신용정보의 언더라이팅 활용이 제한되어 있는 현실에서 이를 법제도 내로 흡수하면서 개인의 사생활 유지라는 목적을 동시에 달성되도록 하는 재정적 언더라이팅 기법의 강화가 특히 중요하리라 생각된다. 아울러 언더라이팅 업무를 효과적 효율적 수행을 통해 일관성 있는 의사결정이 이루어질 수 있도록 지원하는 언더라이팅 시스템구축을 통해 정형화된 인수과정은 결정시스템화하고, 복잡한 위험의 경우 자문 시스템으로 운영하여 간단한 언더라이팅 업무는 구축된 시스템을 통해 즉각 해결함으로써 시간을 절약할 수 있고, 언더라이팅 인력은 보다 전문적인 부문에 집중하도록 해야 할 것이다. 마지막으로, 비표준위험시장의 활성화를 위해서는 현재의 제약조건인 생명보험 상품개발을 세트형에서 조립형으로 전환하고, 재보험으로 위험을 분산하여 비표준위험의 인수를 증대하여야 할 것이다. 이와 더불어 언더라이팅 과정에서 얻어진 피보험자의 사정자료를 활용하여 고객에게 필요한 의료정보 등을 제공함으로써, 피보험자와 유대관계를 돈독히 하여 기존계약이 계속 유지되도록 하며, 추가계약이 이루어지도록 해야 할 것이다. 이상과 같은 비표준위험의 언더라이팅 개선방안이 보다 효과적으로 수행되고 발전하기 위해서는 통계축적 및 관리, 전문 언더라이터 양성, 전산을 이용한 언더라이팅 확대 등이 이루어져야 하므로 향후 이에 대한 집중적인 연구가 있어야 할 것이다.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.432-445
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• 2018

For health care professionals(HCPs) who have relatively higher possibility of exposing tuberculosis(Tb), it is important for them to equip with proper levels of knowledge and prevention activities. In terms of establishment of Tb education model for junior HCPs, therefore, literature review was done alongside 129 junior HCPs and 14 HCPs were asked to answer questionnaires and telephone survey. The results are follows.; Firstly, six educational themes such as epidermiology of Tb, Tb transmission and patho-physiology, test and diagnosis, latent Tb, Tb treatment, and Tb prevention were identified, based on the literature review. Secondly, the junior HCPs showed lower levels of knowledge regarding epidermiology, transmission and patho-physiology and latent Tb, compared to the other themes. When education courses are planned, longer period of time should be given to the lower level of knowledge areas. Thirdly, the HCPs emphasized that definition and type of Tb should be well integrated into the education in particular epidermiology education. They also responded that hospital infection and infection cycle of Tb need to be addressed during educational session about transmission and patho-physiology. in addition, they said that specific and detailed contents about diagnosis and group examination should be carefully delivered during the education, along with diagnosis, test and application of personal protective devices during education of latent Tb. They also answered that patient education and adverse effect of Tb medication should be taught during Tb treatment session, as well as self activities of health promotion for junior HCPs and systematic TB education as key way of Tb prevention. As the findings were from limited numbers of respondents and contained the sampling bias, the result has to be carefully interpretated prior to generalization. Therefore, further survey with larger study population is required in terms of development of Tb education model.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.196-208
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• 1994

Some additional fungi were collected during two field trips to Ullung Island in July and September of 1992. Through the observation of agaric fungi, 36 mushrooms were identified to the species or subspecies and are listed below. Among them, three species and one subspecies, Mycena luteopallens, Mycena macrocystidiata, Amanita hemibapha ssp. similis, and Pluteus petasatus, were confirmed new to Korea and are registered here with descriptions.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.280-291
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• 2007

Much research has been conducted in the field of phytoremediation since the discovery of the range of plants known as hyperaccumulators. Research has focused simultaneously on elucidating the mechanism of metal(loid) accumulation and development of practical techniques to enhance accumulation efficiency. To date, it is generally understood that there are five specific mechanisms employed by hyperaccumulating plant species that are either not or under utilized by non-hyperaccumulators. These include 1) enhanced metal(loid)s uptake through the root cell, 2) enhanced translocation in plant tissue, 3) detoxification and sequestration, 4) enhanced metal availability in soil:root interface, and 5) active root foraging toward metal(loid) enriched soils. Among these mechanisms, understanding of the plant-root effect on metal(loid) dynamics and subsequent plant uptake is vital to overcome the inherit limitation of phytoremediation caused by low metal(loid) solubility in soils. Plant roots can influence the soil chemistry in the rhizosphere through changes in pH and exudation of organic compounds such as low-molecular-weight organic acids (LMWOAs) which consequently change metal(loid) solubility. The decrease in soil pH by plant release of $H^+$ results in increased metal solubility. Elevated levels of organic compounds in response to high metal soil concentrations by plant exudation may also increases metal concentration in soil solution through formation of organometallic complexes.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.141-149
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• 2014

This paper describes a method to insert and detect watermark or fingerprint to/from videos in low-computing powered system as Android platforms. Fingerprint, which is a kind of watermark, has features such as patterns that contain information. The inserting frame numbers in video-stream and the positions in a picture were chosen from the encrypted user ID to insert the watermarks. The used encrypt algorithm is the HIGHT algorithm which was developed for low-computing powered systems by KISA(Korean Internet & Security Agency). Subtracting an inferred picture from the previous picture was used to extract a candidate feature. Median filtering was used to get rid of noise and stabilize the candidate feature. New algorithm that reduces calculating steps of the median filtering was developed and applied for low-specification systems. The stabilized features were accumulated over 150 times and calculated by correlation coefficient method to recognize the patterns. We examined 22 videos and successfully detected the patterns from 21 videos. The correlation coefficient r values that we examined through this study exceeded over 0.79 more than the threshold (0.7).

• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.369-375
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• 2014

This study examined the changes of microstructural compositions in cement matrix according to the depth from the surface of a reinforced concrete (RC) column exposed to fire. The RC column was exposed to a standard fire for 180 minutes. After the fire test, core samples passing through the column section were obtained. Using the core samples, the remaining fractions of calcium-silicate-hydrates (C-S-H) and calcium hydroxide in cement matrix at the surface, the depth of 40 mm and 80 mm and the center (175 mm) were examined using thermal gravimetric analysis (TGA) and X-ray diffraction analysis (XRDA). Using nuclear magnetic resonance (NMR) technique, the silicate polymerization of C-S-H in cement matrix was also evaluated. The experimental results indicated that the amount of C-S-H loss at the center of column experiencing the transferred fire temperature of $236^{\circ}C$ has been underestimated as the TGA results showed the highest C-S-H contents are located at the depth of 80 mm, where the transferred fire temperature is $419^{\circ}C$. Moreover, the destruction of silicate connections at the center was observed as similar as that at the depth of 40 mm, where the transferred fire temperature was $618^{\circ}C$. This might be attributed to the temperature changes during cooling time after the fire test was neglected. Due to the relatively low thermal conductivity of concrete, the high temperature, which can affect the change of microstructure in cements, will hold longer at the center of the column than other depth.