• The KIPS Transactions:PartB
• /
• v.13B no.7 s.110
• /
• pp.643-652
• /
• 2006

Decision trees are mainly used for the classification and prediction in data mining. The distribution of spatial data and relationships with their neighborhoods are very important when conducting classification for spatial data mining in the real world. Spatial decision trees in previous works have been designed for reflecting spatial data characteristic by rating Euclidean distance. But it only explains the distance of objects in spatial dimension so that it is hard to represent the distribution of spatial data and their relationships. This paper proposes a decision tree based on spatial entropy that represents the distribution of spatial data with the dispersion and dissimilarity. The dispersion presents the distribution of spatial objects within the belonged class. And dissimilarity indicates the distribution and its relationship with other classes. The rate of dispersion by dissimilarity presents that how related spatial distribution and classified data with non-spatial attributes we. Our experiment evaluates accuracy and building time of a decision tree as compared to previous methods. We achieve an improvement in performance by about 18%, 11%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.9B
• /
• pp.1350-1359
• /
• 2010

Recently many researchers have been proved that general RFID system for proximity authentication is vulnerable to various location-based relay attacks such as distance fraud, mafia fraud and terrorist fraud attacks. The distance-bounding protocol is used to prevent the relay attacks by measuring the round trip time of single challenge-response bit. In 2008, Munilla and Peinado proposed an improved distance-bounding protocol applying void-challenge technique based on Hancke-Kuhn's protocol. Compare with Hancke-Kuhn's protocol, Munilla and Peinado's protocol is more secure because the success probability of an adversary has (5/8)n. However, Munilla and Peinado's protocol is inefficient for low-cost passive RFID tags because it requires large storage space and many hash function computations. Thus, this paper proposes a new RFID distance-bounding protocol for low-cost passive RFID tags that can be reduced the storage space and hash function computations. As a result, the proposed distance-bounding protocol not only can provide both storage space efficiency and computational efficiency, but also can provide strong security against the relay attacks because the adversary's success probability can be reduced by $(5/8)^n$.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05c
• /
• pp.1651-1654
• /
• 2003

이동 단말의 보급이 보편화됨에 따라 이동 객체의 위치 정보를 기반으로 사용자에게 사람이나 사물, 차량 등과 같은 이동 객체의 위치를 파악하여 그에 대한 정보를 제공해 주는 시스템이 필요로 하게 되었나 이러만 이동 객체관리 시스템에서는 계속적으로 위치 정보가 변화하는 이동 객체의 특성상 데이터의 빈번한 갱신이 일어나게 되고 DBMS에 명시적으로 저장되지 않은 위치 정보에 대해서도 보다 정확한 위치를 사용자에게 제공해 주어야 한다. 그러나 차량의 위치 추적과 같이 적용 개체가 차량에 한정된 경우 이동 경로가 도로상으로 제한되어 있으므로 이동 경로를 예측하기 힘든 사람과 같은 객체와는 특성이 나르나 따라서 차량 객체에 대해 보다 효과적인 서비스를 제공해 주기 위해서는 사람에 대한 위치 추적과는 다른 갱신 정책과 불확실한 위치의 추정 기법이 필요하다. 본 논문에서는 공간 데이터에 저장된 도로의 위상 정보와 차량의 속도 속성을 이용한 갱신 정책을 정하여 갱신 빈도수로 줄이고 도로 레이어의 위상 정보를 통해 불확실한 과거 및 미래의 위치로 추정하는 기법을 제안한다. 제안한 갱신 정책은 차량의 속도를 고려하여 현재의 위치에서 도로상의 교차점에 도착하는 시점의 위치를 예측하여 데이터의 갱신 시점으로 결정한다. 또한 불확실한 위치에 대한 추정은 이동하는 도회와 대응되는 위상 정보를 기반으로 차량의 이동 방향을 예측하 여 불확실한 미래의 위치를 결정할 수 있으며 명시적으로 저장되지 않은 과거 위치 정보의 검색에 대한 요청이 발생했을 경우 위상 정보를 이용하여 위치를 보정하고 사용자에게 보나 높은 정확성을 지닌 정보를 제공해 줄 수 있다.다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.1
• /
• pp.97-102
• /
• 2012

A hermetically sealed oil transformer is designed by applying expanding function of the tank due to the volume changes of the insulation oil according to the temperature rises. When the insulation oil expands, an increase in the volume of the corrugated fin prevents a pressure rise of the transformer. For a wind turbine transformer, a vegetable-oil-immersed transformer has the advantages of excellent biodegradation and fire-resistant properties like an exceptionally high fire point. When vegetable oil is substituted for mineral oil, however, the maximum winding temperature rises because of the decrease in the internal circulation flow rate resulting from the variations of the oil's physical characteristics, such as density and viscosity. The purpose of this study is to develop a hermetically sealed vegetable oil transformer that can be applied in a wind turbine and to analyze the thermal stability of the active part of the transformer to deal with pressure variations due to the temperature changes. In addition, thermal tests for the vegetable oil transformer have been performed, and the measured values are compared with the analysis results.

• Journal of the Korea Society for Simulation
• /
• v.21 no.1
• /
• pp.55-68
• /
• 2012

Recently it is important to understand service supply chain because the economy moves from manufacturing to services. However, most of existing supply chain research focuses exclusively on the manufacturing sector. To overcome this situation, it needs to investigate and analyze service supply chain. Simulation is one of the most frequently used techniques for analysis and design of complex system. Service supply chain is complex and large systems that require an accurate designing phase. Especially, it is important to examine closely the dynamically interactive behavior of the different service supply chain components in order to predict the performance of the servcie supply chain. In this paper, we develop a conceptual model of service supply chain. Then, we present a new procedure to develop simulation model for the developed conceptual model of service supply chain, based on the UML analysis and design tools and on the ARENA simulation language. The two main characteristics of the proposed procedure are the definition of a systematic procedure to design service supply chain and of a set of rules for the conceptual model translation in an ARENA simulation language. The goal is to improve the knowledge on service supply chain management and support the simulation model development efficiency on service supply chain.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.352-360
• /
• 2008

The extraction yield and storage stability of Codium fragile pigments extracted in acetone, ethanol or methanol were studied. Methanol was the most effective solvent for pigment extraction, providing an extraction yield of $25.0{\pm}2.10\;mg/g$ (my base). As shown by TLC and HPLC analysis, chlorophyll a(0.40 mg/g) and chlorophyll b(1.94 mg/g) were the major pigment components in dried Codium fragile. The total chlorophyll content of Codium fragile stored a 40C in light or dark conditions for 30 weeks remained at 23.2% and 58.4% respectively. The effect of metal ions ($Cu^{++}$, $Zn^{++}$, $Fe^{++}$ and $Mg^{++}$) on pigment stability was analyzed Among the four metal ions $Cu^{++}$ was the most effective stabilizer of Codium fragile pigments during storage, and $Zn^{++}$ ion was the second most effective. In the presence of 1 mM $Cu^{++}$, the total chlorophyll retained in Codium fragile stored at 40C in light or dark conditions was increased to 47.0% and 88.8% after 30 weeks storage, respectively. The optimum concentrations of $Zn^{++}$ and $Cu^{++}$ for pigment stabilization under dark conditions were 0.5 mM and 0.1 mM, respectively.

• YAKHAK HOEJI
• /
• v.40 no.5
• /
• pp.608-615
• /
• 1996

6-[(N-3,4-Difluorophenyl)amino]-7-chloro-5,8-quinolinedione(RCK4) was tested for antifungal activities, against systemic infections with Candida albicans in normal mice. The therapeutic potential of RCK4 had been assessed in comparison with ketoconazole and fluconazole. RCK4 had $ED_{50},\;0.30{\pm}0.14$ but ketoconazole and fluconazole had $ED_{50},\;8.00{\pm}0.73,\;10.00{\pm} 0.43mg/kg$ respectively. Intraperitoneally administered RCK3 at the $ED_{50}$ for 7 days and 14 days reduced Candida albicans colony count in the kidneys and liver as well as ketoconazole and fluconazole at these $ED_{50}$. And administered RCK4 at the $ED_{50}$ for 14 days improved survival rates as well as ketoconazole. Acute oral toxicity studies of RCK4 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK4 were low and $LD_{50}$ values were over 2,850mg/kg in ICR mice. The genotoxicities of RCK4 had been evaluated. RCK4 was negative in Ames test with Salmonella typhimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK4 with in vivo mouse micronucleus assay. RCK4 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK4 has no genotoxic potential under these experimental conditions.

• The Korea Journal of Herbology
• /
• v.30 no.6
• /
• pp.55-61
• /
• 2015

Objectives : Yongdamgosam-hwan(YGH) has been used as a traditional medicine from old times for antiinflammatory effects. Streptococcus mutans(S. mutans) is known as a prime bacteria responsible for causing caries by forming a biofilm referred to as dental plaque on the tooth surface. But antimicrobial activity of YGH with dental disease is not sufficiently understood. This study was designed to investigate the effects of YGH ethanol extract on antimicrobial effect against Streptococcus mutans.Methods : The antimicrobial effect of YGH ethanol extract was assessed by the paper disk diffusion method and optical density method to determine minimum inhibition concentration(MIC), also observed by fractional inhibitory concentration index(FICI) and time-kill assay to figure out the synergic effect on the combination of YGH ethanol extract with antibiotics.Results : The YGH ethanol extract 500 μg was 7.5-8.5 mm diameter of clear zone of inhibition against Streptococcus mutans in a concentration-dependent manner and MIC was 250 μg/mL. The administration of the ethanol extract in combination with gentamicin and streptomycin induced a reduction of ≥4-8-fold in all tested bacteria. Furthermore, time-kill study was found that a combination of YGH ethanol extract with oxacillin and streptomycin produced a more rapid decrease in the concentration of bacteria CFU/mL than the YGH ethanol extract or antibiotics alone.Conclusions : As a result, the YGH ethanol extract has good antimicrobial effects. And the results suggest that YGH could be employed as a natural antibacterial agent in dental care products.

• Korean Journal of Agricultural Science
• /
• v.24 no.2
• /
• pp.132-137
• /
• 1997

Effective storage facilities are required to stabilize the price of agricultural and marine products to preserve their qualities due to the big fluctuation of shrimp price in Korea. It is easy to make the cave because of good conditions of the land configuration, soil and convenient transportation. The cave storage can save the cost about 40% in building site and equipment, and about 50% in maintenance comparing to existing low temperature storage facilities. The cave storage provide to improve the quality of their stored products with the low heat conductivity, the constant temperature and humidity year round. Therefore, more low temperature storage facilities are required because the items are expanded from potatoes, sweet potatoes, onions, garlics, apples and chestnuts to tangerines, grapes, cabbages, radishes, and wet ginsengs. The demands of the low temperature storage facilities can be substituted into the cave storage facilities. Thus, studies are conducted to observe the changes of the components of the pure and the seasoned salted shrimps with fermentation period during stored at room temperature in cave and to establish the storing at underground facilities to produce high quality salted fish to make profit.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.2
• /
• pp.143-148
• /
• 1999

Objectives: We studied correlations between neuropsychological tests and perceptual disorder in patients with head trauma and psychiatric patients in order to explore the functional localization of brain in perceptual disorders. Methods: Halstead Reitan Neuropsychological Test Battery, Korean Wechsler Intelligent Scale, and Minnesota Multiphasic Peronality Inventory(MMPI) were administered to one hundred ninteen patients consisting of sixty nine psychiatric patients and fifty patients with brain damage. We tested the correlation between results of neuropsychological tests and peceptual disorder scale PDS) made from nine items related with perceptual disorder in MMPI. T-tests between twenty one higher scorers and seventeen lower scorers of PDS were also performed in the psychiatric group. Results: In brain damage group, significant correlations were found in tests related with function of frontal lobe such as category tests, trail making tests, tactual performance test, and fingertip number writing test, and significant correlations were also noted in the tests related with function of right hemisphere such as tactual performance test, performance, picture completion, picture arrangement and block design. Tests related with subcortical function such as digit symbol test, arithmetic and digit span were signigicantly correlated, too. In psychiatric group, there were significant differences of PDS in the tests related with function of right hemisphere such as picture completion, block design, and right laterality index, and in the tests related with function of left hemisphere such as comprehension, vocabulary, and similarities. Conclusion: Perceptual disorder seems to be related with functions of frontal lobe, right hemisphere, and subcortex in both groups. In a psychiatric group, left hemisphere may be also partially related with perceptual disorder.