• Atmosphere
• /
• v.20 no.4
• /
• pp.467-482
• /
• 2010

In this study, characteristics of various stability indexes (SI) and environmental parameters (EP) for the lightning are analysed by using 5 upper air observatories (Osan, Gwangju, Jeju, Pohang, and Baengnyeongdo) for the years 2002-2006 over South Korea. The analysed SI and EP are the lifted index, K-index, Showalter stability index, total precipitable water, mixing ratio, wind shear and temperature of lifting condensation level. The lightning data occurred on the range of -2 hr~+1 hr and within 100 km based on the launch time of rawinsonde and observing location are selected. In general, summer averaged temperature and mixing ratio of lower troposphere for the lightning cases are higher about 1 K and $1{\sim}2gkg^{-1}$ than no lightning cases, respectively. The Box-Whisker plot shows that the range of various SI and EP values for lightning and no lightning cases are well separated but overlapping of SI and EP values between lightning and no lightning are not a little. The optimized threshold values for the detection of lightning are determined objectively based on the highest Heidke skill socre (HSS), which is the most favorable validation parameter for the rare event, such as lightning, by using the simulation of SI and EP threshold values. Although the HSS is not high (0.15~0.30) and the number and values of selected SI and EP are dependent on geographic location, the new threshold values can be used as a supplementary tool for the detection or forecast of lightning over South Korea.

• KIISE Transactions on Computing Practices
• /
• v.22 no.8
• /
• pp.375-380
• /
• 2016

The proliferation of online social networking services (OSNSs) and smartphones has enabled people to easily make friends with a large number of users in the online communities, and interact with each other. This leads to an increase in the usage rate of OSNSs. However, individuals who have immersed into their digital lives, prioritizing the virtual world against the real one, become more and more isolated in the physical world. Thus, their socialization processes that are undertaken only through lots of face-to-face interactions and trial-and-errors are apt to be neglected via 'Add Friend' kind of functions in OSNSs. In this paper, we present a friend recommendation system based on the on/off-line contextual information for the OSNS users to have more serendipitous offline interactions. In order to accomplish this, we modeled both offline information (i.e., place visit history) collected from a user's smartphone on a 3D tensor, and online social data (i.e., friend relationships) from Facebook on a matrix. We then recommended like-minded people and encouraged their offline interactions. We evaluated the users' satisfaction based on a real-world dataset collected from 43 users (12 on-campus users and 31 users randomly selected from Facebook friends of on-campus users).

• Horticultural Science & Technology
• /
• v.31 no.5
• /
• pp.607-616
• /
• 2013

Light with two faces, beneficial and harmful effects is an important signal for every living cell. Optimal adaptation to light environment enhances the fitness of an organism and survival in nature. Understandings of light quality and plant growth provide with the economical guides for artificial light sources like LEDs. Compared with those under white light, the 1 week seedlings of Chinese cabbage (Brassica rapa) under monochromic red and blue light showed normal development and growth. In contrast to extremely long and etiolated hypocotyls of the seedlings under dark, those under far-red etiolated were extremely short. Based on the microarray analysis, blue light induced the vigorous development and growth and two fold changes of transcripts than red light condition. To have insight of gene products under different light qualities conditions, GO term enrichments were calculated and each gene according to their GO terms were categorized. The blue and red lights affected the expressions of genes related to biological process. Especially, the genes related to metabolic process and developmental process and plastid and chloroplast in the cellular component category were induced under blue light. This study provided the molecular biological evidence for various light qualities on the growing process of B. rapa.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.12C
• /
• pp.1692-1706
• /
• 2004

Recently, there are rapid development of information and communication and rapid growth of e-business users. Therefore we try to solve security problem on the internet environment which charges from wire internet to wireless internet or wire/wireless internet. Since the wireless mobile environment is limited, researches such as small size, end-to-end and privacy security are performed by many people. Wireless e-business adopts credit card WPP protocol and AIP protocol proposed by ASPeCT. WAP, one of the protocol used by WPP has weakness of leaking out information from WG which conned wire and wireless communication. certification chain based AIP protocol requires a lot of computation time and user IDs are known to others. We propose a Micro-Payment protocol based on credit card. Our protocol use the encryption techniques of the public key with ID to ensure the secret of transaction in the step of session key generation. IDs are generated using ECC based Weil Paring. We also use the certification with hidden electronic sign to transmit the payment result. The proposed protocol solves the privacy protection and Non-repudiation p개blem. We solve not only the safety and efficiency problem but also independent of specific wireless platform. The protocol requires the certification organization attent the certification process of payment. Therefore, other domain provide also receive an efficient and safe service.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.4
• /
• pp.389-398
• /
• 2002

As the necessity of land information has increased according to development of computer and Information-communication, people have been interested in the satellite measurement system that can update Cadastral and Geographical information rapidly and exactly. Most Cadastral base points which had limitation of measurement technology in the 1910s were less accurate and were destroyed through the Korean War. They also many problems in the process of reinstallation. So, they require the quick and correct method of measurement in re-equipment of a base point and a parcel based survey and so on. This study intends to present the GPS survey direction by understanding and analysing all sorts of problems rising in case of applying the GPS to cadastral area in order to increase the efficiency of the GPS measurement, and also develop the GPS kinematic survey program to apply to the efficiency of a kinematic survey. As a result of research, I could confirm the accuracy of Cadastral base points in Kwangju area by using Korea GPS array and a base point, and could get the result similar to existent cadastral survey result with the coordinate conversion program of Cadastral technology research institute. We however have to pay our attention to the transformation of the plane coordinates because the difference between tens of cm and the existing result can outbreak according to the Gauss conformal double projection method. And, I could figure out the practicality of the developed GPS kinematic survey program, compared with common use program. I expect that it can be applied to the digital cadastral survey and the cadastral map renewal as well.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.25 no.4
• /
• pp.313-332
• /
• 2014

With the increased creation, distribution, and use of image in context of the development of digital technologies and internet, research endeavors have accumulated drastically. As two dominant aspects of image retrieval have been considered content-based and concept-based image retrieval, concept-based image retrieval has been focused in the field of Library and Information Science. This study aims to systematically review the accumulated research of image retrieval from the perspective of LIS field. In order to achieve the purpose of this study, two data sets were prepared: a total of 282 image retrieval research papers from Web of Science, and a total of 35 image retrieval research from DBpia in Kore for comparison. For data analysis, systematic review methodology was utilized with bibliographic analysis of individual research papers in the data sets. The findings of this study demonstrated that two sub-areas, image indexing and description and image needs and image behavior, were dominant. Among these sub-areas, the results indicated that there were emerging areas such as collective indexing, image retrieval in terms of multi-language and multi-culture environments, and affective indexing and use. For the user-centered image retrieval research, college and graduate students were found prominent user groups for research while specific user groups such as medical/health related users, artists, and museum users were found considerably. With the comparison with the distribution of sub-areas of image retrieval research in Korea, considerable similarities were found. The findings of this study expect to guide research directions and agenda for future.

• The Journal of Korean Association of Computer Education
• /
• v.15 no.3
• /
• pp.37-47
• /
• 2012

One of the major goals in high school Informatics is for students to develop creative problem-solving abilities based on knowledge on computer science. Thus, the contents of the textbooks should be accurate and appropriate. However, we discovered that the current Informatics textbooks contain the untrue and/or inappropriate descriptions of main memory and virtual memory. The textbooks describe that main memory is composed of RAM and ROM. The virtual memory is described as a technique in which a part of the secondary storage is utilized as main memory to execute an application of which size is larger than that of main memory. In this study, we attempted to uncover the root causes of the fallacies, and suggest the accurate explanations by comparing with renowned books adopted in most schools worldwide including USA. Our study reveals that it is inappropriate to include ROM in main memory from the memory hierarchy perspective. Virtual memory is a technique that provides convenience to programmers, through which an operating system loads the necessary portion of a program from secondary storage to main memory. As for the advantages of virtual memory in the current computer systems, the focus should be on providing the effective multitasking capability, rather than on executing a larger program than the size of main memory. We suggest that it is appropriate to exclude virtual memory in textbooks considering its complexity.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.242-246
• /
• 2006

최근 들어 전 세계적으로 유량측정 분야의 큰 변화의 방향은 자동화이다. 전자, 전기 기술과 정보통신 기술의 발달을 유량측정 분야에 적용하여 자동적으로 유량측정을 수행하고 실시간으로 모든 유량자료를 수집하는 시스템을 구성하려는 연구가 활발하게 진행중이다. 최근에 초음파 유량계와 더불어 자동 유량측정 기법으로 각광을 받고 있는 기법이 유속지수법(index velocity method)이다. 유속지수법의 원리는 매우 간단하다. 수위 기록을 통하여 수위-면적 관계로부터 흐름 단면적을 구하고, 임의의 영역에서 측정된 유속이 단면 평균 유속으로 환산될 수 있다면, 흐름 단면적과 평균 유속에 의해 연속적으로 유량을 구할 수 있다. 유속지수법에서 가장 중요한 것이 전체 평균 유속을 대표할 수 있는 유속지수를 정확하고 효율적으로 측정하는 것이다. 유속지수법에 의한 연속 유량측정 목적으로 최근에 ADVM(Acoustic Doppler Velocity Meter)이 개발되어 이용되고 있다. ADVM은 수중에 초음파를 발사해서 산란체에서 반사되어 돌아오는 초음파의 주파수 편이, 즉 도플러 효과를 이용하여 유속을 측정하는 유속계이다. 본 연구에서는 ADVM을 괴산댐 하류에 위치한 시험하천에 설치하여, 유속지수법에 의한 유량측정기법을 적용하고 그 특성을 분석하였다. 유속지수법으로 측정된 유량을 괴산댐 방류량과 비교한 결과 평균 4.0%의 상대오차를 지니고 있어 비교적 정확한 연속 유량측정이 가능한 것으로 나타났다. 이와 같은 유속지수법을 하천 유량측정에 활용하면 보다 정확한 유량을 연속적으로 자동화하여 측정할 수 있을 것으로 기대된다.연계모형의 한계로 인하여 두 모형의 통합모형이 필요하다. 즉, 강우 혹은 월류유량으로 발생한 지표유량 중 일부분이 과부하가 발생하지 않는 유입구 지점을 통과할 때 배수시스템으로 유입되는 것을 고려할 수 있고, 유입된 유량은 배수시스템 내의 흐름에 반영되도록 배수시스템과 침수해석모형을 통합한 모형 개발이 필요하다. 그러기 위해서는 지표면과 배수시스템에 대한 수리학적 관계를 정립하여야 한다. 본 연구에서는 배수시스템 해석 모형과 도시침수해석 모형을 통합하고, 두 모형간의 유량의 전송과정을 수리학적 관계를 고려한 dual-drainage 도시침수해석모형을 개발하였다. 이를 위해 도시지역 배수시스템 해석 모형으로 널리 이용되고 있는 SWMM모형을 이용하여 지표면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기

• The Journal of the Korea Contents Association
• /
• v.22 no.7
• /
• pp.524-539
• /
• 2022

With the advent of generative artificial intelligence technology, it became possible to create a virtual human, and produce a lecture video only with textual information. It is expected that the virtual human will enhance the efficient production of educational contents and the student's entertainment experience and satisfaction. However, there have been still few studies that have demonstrated the process of how virtual human technology reaches students' satisfaction. Therefore, the purpose of this study is to empirically examine whether the human likeness, which is the main characteristic of a virtual human based on Uncanny Valley theory, affects human experience and satisfaction. In particular, human likeness of the Uncanny Valley theory was subdivided into human likeness in the visual and verbal dimensions, and the process of reaching satisfaction was understood based on the experience economy model. In particular, human similarity in Uncanny Valley theory was classified as similarity in the visual and language levels, and the process of reaching satisfaction based on the experiential economic model was analyzed with a partial least squares structure model equation (PLS-SEM). The survey was conducted online for a panel of office workers at a specialized research institution in China. The results indicate that both the visual and verbal human likeness had a positive effect on experience economy factors (education, entertainment, esthetic, escape), and then these experiential factors had a significant effect on satisfaction. The results also provide some suggestions to consider when designing educational contents by virtual human.

• Journal of Global Scholars of Marketing Science
• /
• v.7
• /
• pp.261-281
• /
• 2001

As a new environment, the Internet proposes to us the innovative change of our life. With difficulty, we can go after the Internet's potentiality and the growth speed of technology. In the new stream of innovation technology, we can probably feel the fear of tremendous changes, the reverse, also hope to get the opportunity that come out of Internet world. EC(Electronic Commerce) that out of the evolution of Internet technology gets a coporation changes to survive in 21st century. So the corporation must set the strategy to fit a Internet focused society. As one of them, a virtual store is opened on the Internet. Recently, there has been much attention to the Internet shopping mall as a new distribution channel and marketing tool. This study analyzed that the system environment, perceived product risk, easy of order, perceived security risk would have impact on the customer satisfaction in Electronic Commerce. The Purpose of this study is to develope the concept of the determinants of customer satisfaction and to test a theoretical framework that attempts to explain how the perception of satisfaction in Electronic Commerce. The proposed hypotheses were tested internet shopping mall users and the study results show all hypotheses are supported.