• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1847-1870
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• 2021

With the development of information and communication technologies, especially wireless networks and cell phones, the e-voting system becomes popular as its cost-effectiveness, swiftness, scalability, and ecological sustainability. However, the current e-voting schemes are faced with the problem of privacy leakage and further cause worse vote-buying and voter-coercion problems. Moreover, in large-scale voting, some previous e-voting system encryption scheme with pairing operation also brings huge overhead pressure to the voting system. Thus, it is a vital problem to design a protocol that can protect voter privacy and simultaneously has high efficiency to guarantee the effective implementation of e-voting. To address these problems, our paper proposes an efficient unidirectional proxy re-encryption scheme that provides the re-encryption of vote content and the verification of users' identity. This function can be exactly applied in the e-voting system to protect the content of vote and preserve the privacy of the voter. Our proposal is proven to be CCA secure and collusion resistant. The detailed analysis also shows that our scheme achieves higher efficiency in computation cost and ciphertext size than the schemes in related fields.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.152-152
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• 2023

하천의 건강성을 평가하기 위해 일반적으로 수생태계 건강성 지표(TDI, BMI, FAI, HRI, RVI)가 사용되고 있다. 이 지표는 5가지 등급으로 구분하여 매우 좋음(A), 좋음(B), 보통(C), 나쁨(D), 매우나쁨(E)으로 구분된다. 하지만, 하천의 건강성 관점에서 수질, 토지이용, 지리적 특성, 경관지수와의 상관성을 바탕으로 어떤 영향을 미치는지에 대한 연구가 필요하다. 본 연구에서는 하천의 수생태계 건강성에 영향을 미치는 환경적 인자들과의 관계성을 분석하여 수생태계 건강성이 '좋음'에 해당되는 하천으로 분류하고자 한다. 이를 통해 환경적 인자들의 임계값을 산출하여 하천 관리에 대한 구체적인 우선순위 설정 방안을 제안하고자 한다. 낙동강대권역을 대상으로 수질, 토지이용, 지리적 특성, 경관지수의 여러 변수 중 수생태계 건강성과의 관계에서 대표성을 나타낼 수 있는 환경적 인자를 선정하기 위하여 정준상관분석(CCA)을 수행하였다. 또한 모델 기반의 클러스터 분석을 활용하여 소권역별로 수생태계 건강성이 '좋음'에 해당할 확률을 파악하고, 여기에 해당하는 소권역에 대하여 각각의 환경적 인자에 대한 임계값을 정량적으로 평가하였다. 본 연구에서는 하천의 환경 인자들과의 관계를 분석하여 수생태계 건강성을 평가하고 하천 관리에 대한 구체적인 우선순위를 파악하는 방법을 제안한다. 주성분 분석 및 모델 기반 클러스터 분석을 사용하여 각 소권역에 대한 환경 인자의 임계값을 평가하고, 정책 결정자들이 하천의 건강성을 유지하고 개선할 수 있는 정보를 제공할 수 있다.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.3
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• pp.209-214
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• 2010

This paper proposes an algorithm of segmentation and title detection for document image. The automated title detection method that we have developed is composed of two phases, segmentation and title area detection. In the first phase, we extract and segment the document image. To perform this operation, the binary map is segmented by combination of morphological operation and CCA(connected component algorithm). The first phase provides segmented regions that would be detected as title area for the second stage. Candidate title areas are detected using geometric information, then we can extract the title region that is performed by removing non-title regions. After classification step that removes non-text regions, projection is performed to detect a title region. From the fact that usually the largest font is used for the title in the document, horizontal projection is performed within text areas. In this paper, we proposed a method of segmentation and title detection for various forms of document images using geometric features and projection profile analysis. The proposed system is expected to have various applications, such as document title recognition, multimedia data searching, real-time image processing and so on.

• Ocean and Polar Research
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• v.32 no.1
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• pp.1-13
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• 2010

To assess short-term variation of summer phytoplankton community structure in different water masses, phytoplankton and environmental factors were monitored from 31 stations on and off the southern coasts of Korea, from June 18 to June 20 2009. According to multidimensional scaling (MDS) and cluster analysis based on phytoplankton community data from each station, the southern sea was divided into two groups. The first group included stations in the south-eastern region of Jeju Island, which is strongly influenced by the Kuroshio warm current. The second group located along the coastal region of the southern sea, which was mainly comprised of Bacillariophyceae and Crytophyceae. Of these stations, St. 13 and 28 formed a temperature front caused by different hydrological conditions. In particular, nutrients and Chl.a concentrations in these two stations were significantly higher compared to those in the other stations. This indicates that phytoplankton population and subsequent microalgal growth under high nutrient concentrations vary in different water masses. Our results support the theory that phytoplankton community structure in the southern sea of Korea can be influenced on a short-term scale by different water masses and currents.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.321-330
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• 2014

This study was performed to investigate relation between riparian vegetation and environmental factor and to predict riparian vegetation succession in Nakdong river, which is typical sand river in Korea Peninsula. We searched 5 natural levee and installed 84 quadrats in Nakdong river near by Andong city. Also, We analyzed flora, vegetation cover degree, topography, soil moisture, organic content, pH, electrical conductivity and soil texture. According to the result of CCA (canonical correspondence analysis), which considered both investigated vegetation data and environmental factor, vegetation were divided down three groups, and each group was difference by height above ordinary water level, organic content and sand. In addition, the most powerful factor was indicated the height above ordinary water level.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.19-26
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• 2005

Digital technology continually makes a space evolves. The real-time behavior design communicates the data with the situation of circumference of the space(visitors moving, interior and exterior situations). The space form was changed because it interfaces in real time. The purpose of this study was finding out the characteristics of real-time behavior space design through the analysis of space formative languages, sensorium, S-R and material. This study will be the one of basic references for the digital space design. The boundary of this study set limits to the works of digital space designer who applies the real-time exchanging data to their design among the digital space design works from 1996 to 2004. But it excepted from the real-time behavior space in virtual realty. Therefore, the objects of this study were the works of onl and NOX(paraSITE, Trans-port 2001, Muscle, MotormeCCa, Handdrawspace, Saltwater Pavilion, Son-O-House, H2O Expo). The method was the contents analysis of space formative languages(Greg Lynn's ten space formative languages; bleb, blob, branch, flower, fold, lattice, teeth, shred, skins and strand), sensorium, S-R and material. The results of the study are as follows: 1) The organizational elements; Space formative languages(bleb, blob, fold, shred, skins, strand), stimulation(Human Participation, Human Moving, Weather Conditions), and response(Spatial Moving, Sound Pattern, Lighting Pattern, color Pattern, Activating Particles, Moving Picture, Virtual Friend) 2) The material Use; Sound, lights, and network have been used in the space. Immaterial matter will be used the main material of space design in 21"'century, 3)The spatial types; formal changing of space, projecting immaterial elements, and changing the sound.

• Journal of agriculture & life science
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• v.45 no.3
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• pp.1-7
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• 2011

This study was carried out to provide the basic information for effective preservation and management of forest community of Nari basin in Ulleung Island. Forest community in Nari basin was classified into Fagus engleriana community, Sorbus amurensis community, Pinus densiflora community, Celtis jessoensis community and Alnus maximowiczii community. As the result of DCCA ordination analysis, sea level among environmental factors had high correlation with community distribution. Fagus engleriana community and Sorbus amurensis community correlated highly with aspect, Na content, and C/N ratio. There was a high correlation between Celtis jessoensis community and the content of Ca and K. Alnus maximowiczii community was distributed in site where CEC content is high. Pinus densiflora community was distributed in site where the content of Ca and CEC is high.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.3
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• pp.121-134
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• 2010

With the help of various Layer 2 triggers, Fast Handover for Mobile IPv6 (FMIPv6) considerably reduces the latency and the signaling messages incurred by the handover. Obviously, if not secured, the protocol is exposed to various security threats and attacks. In order to protect FMIPv6, several security protocols have been proposed. To our best knowledge, there is lack of analysis and comparison study on them though the security in FMIPv6 is recognized to be important. Motivated by this, we provide an overview of the security protocols for FMIPv6, followed by the comparison analysis on them. Also, the security threats and requirements are outlined before the protocols are explored. The comparison analysis result shows that the protocol presented by You, Sakurai and Hori is more secure than others while not resulting in high computation overhead. Finally, we introduce Proxy MIPv6 and its fast handover enhancements, then emphasizing the need for a proper security mechanism for them as a future work.

• Journal of Korean Society on Water Environment
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• v.39 no.2
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• pp.181-193
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• 2023

Distribution changes in microalgae communities were studied in the Nakdonggang River at two sampling stations (St.1 Gyeongcheongyo Bridge (GB) and St.2 Daedong Wharf (DW)) at monthly intervals from January 2021 to November 2021. A total of 83 taxa included 82 species, 1 forma, belonging to 49 genera, 32 families, 21 orders, and 8 classes. The most important groups were Bacillariophyta and Chlorophyta. The number of species ranged from 5 to 24 in GB, and from 9 to 21 taxa in DW. The contribution of Bacillariophyta to the total species richness was the highest during all survey periods, and Chlorophyta yielded the next highest value in the study area. The dominant taxa were Aulacoseira ambigua, A. ambigua f. japonica, and Ulnaria acus in this study. Cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on Bray- Curtis similarity identified 4 major groups, which corresponded to microalgae assemblages and their characteristic species. Correlation was analyzed through the CCA analysis. It was found that there was a correlation between the microalgae and environmental factors. It was revealed that the divided groups were distinguished because of the differences by the survey period. Therefore, seasonal change was judged as a major factor affecting the distribution of microalgae communities.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.857-862
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• 2016

Background: The prevalence of infection by the liver fluke, Opisthorchis viverrini (O. viverrini), has remained high in Northeast Thailand where it is a major risk factor for the eventual development of cholangiocarcinoma (CCA). The infection is acquired by the consumption of dishes containing unsafely prepared freshwater fish, a dietary tradition which has proved resistant to change. Since many people are aware that dosing with praziquantel (PZQ) is a successful treatment for an episode of the infection, there is a risk that, to avoid the long term consequences, they will engage in a cycle of infection, dosing and reinfection. Objectives: There is a dearth of studies of reinfection by O. viverrini, and the aims of this study were to assess re-infection rates in a typical province of Northeastern Thailand where O. viverrini infection is likely and to investigate factors associated with reinfection. Materials and Methods: A total of infected 607 villagers were treated with PZQ, and those found to be no longer infected were followed up at six-monthly intervals over 12 months. Results: At the end of this period data on 457 subjects were available for analysis using descriptive statistics and logistic regression, and 50 were found to have become reinfected, giving a cumulative reinfection rate of 10.9%. The results of a multiple logistic regression analysis showed that the only factor found to be associated with reinfection was past use of PZQ. Conclusions: Recommendations are made for future larger scale and better designed reinfection studies in the light of limitations of the current study. Further efforts are needed to discourage people from eating fish dishes likely to contain viable metacariae.