• Asia pacific journal of information systems
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• v.18 no.4
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• pp.105-130
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• 2008

Consumers of e-learning market differ from those of other markets in that they are replaced in a specific time scale. For example, e-learning contents aimed at highschool senior students cannot be consumed by a specific consumer over the designated period of time. Hence e-learning service providers need to attract new groups of students every year. Due to lack of information on products designed for continuously emerging consumers, the consumers face difficulties in making rational decisions in a short time period. Increased uncertainty of product purchase leads customers to herding behaviors to obtain information of the product from others and imitate them. Taking into consideration of these features of e-learning market, this study will focus on the online herding behavior in purchasing e-learning contents. There is no definite concept for e-learning. However, it is being discussed in a wide range of perspectives from educational engineering to management to e-business etc. Based upon the existing studies, we identify two main view-points regarding e-learning. The first defines e-learning as a concept that includes existing terminologies, such as CBT (Computer Based Training), WBT (Web Based Training), and IBT (Internet Based Training). In this view, e-learning utilizes IT in order to support professors and a part of or entire education systems. In the second perspective, e-learning is defined as the usage of Internet technology to deliver diverse intelligence and achievement enhancing solutions. In other words, only the educations that are done through the Internet and network can be classified as e-learning. We take the second definition of e-learning for our working definition. The main goal of this study is to investigate what factors affect consumer intention to purchase e-learning contents and to identify the differential impact of the factors between consumers with purchase experience and those without the experience. To accomplish the goal of this study, it focuses on herding behavior and perceived usefulness as antecedents to behavioral intention. The proposed research model in the study extends the Technology Acceptance Model by adding herding behavior and usability to take into account the unique characteristics of e-learning content market and e-learning systems use, respectively. The current study also includes consumer experience with e-learning content purchase because the previous experience is believed to affect purchasing intention when consumers buy experience goods or services. Previous studies on e-learning did not consider the characteristics of e-learning contents market and the differential impact of consumer experience on the relationship between the antecedents and behavioral intention, which is the target of this study. This study employs a survey method to empirically test the proposed research model. A survey questionnaire was developed and distributed to 629 informants. 528 responses were collected, which consist of potential customer group (n = 133) and experienced customer group (n = 395). The data were analyzed using PLS method, a structural equation modeling method. Overall, both herding behavior and perceived usefulness influence consumer intention to purchase e-learning contents. In detail, in the case of potential customer group, herding behavior has stronger effect on purchase intention than does perceived usefulness. However, in the case of shopping-experienced customer group, perceived usefulness has stronger effect than does herding behavior. In sum, the results of the analysis show that with regard to purchasing experience, perceived usefulness and herding behavior had differential effects upon the purchase of e-learning contents. As a follow-up analysis, the interaction effects of the number of purchase transaction and herding behavior/perceived usefulness on purchase intention were investigated. The results show that there are no interaction effects. This study contributes to the literature in a couple of ways. From a theoretical perspective, this study examined and showed evidence that the characteristics of e-learning market such as continuous renewal of consumers and thus high uncertainty and individual experiences are important factors to be considered when the purchase intention of e-learning content is studied. This study can be used as a basis for future studies on e-learning success. From a practical perspective, this study provides several important implications on what types of marketing strategies e-learning companies need to build. The bottom lines of these strategies include target group attraction, word-of-mouth management, enhancement of web site usability quality, etc. The limitations of this study are also discussed for future studies.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.326-334
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• 2007

Purpose: The estrogen receptor (ER), which is over-expressed in ER-positive breast tumors, has been imaged by positron emission tomography (PET) using $[^{18}F]$ labeled estrogen ligands, especially $[^{18}F]FES$. However, $[^{18}F]$ has relatively short-lived half-life ($t_{1/2}$ =1.8 h) and the labeling yield of radio-fluorination is usually low compared with $^{64}Cu\;(t_{1/2}=12.7\;h)$. 1,4,7,10-tetraazacyclododecane (cyclen) is used to form stable metal complexes with copper, indium, gallium, and gadolinium. With these in mind, we prepared cyclen-based Cu complexes which mimic estradiol in aspect of two hydroxyl groups. Materials and Methods: 1.7-Protected cyclen, 1.7-bis (benzyloxycarbonyl)-cyclen was synthesized according to the reported procedure. After introducing two 4-benzyloxybenzyl groups at 4,10-positions, the benzyloxycarbonyl and benzyl groups were removed at the same time by hydrogenation on Pd/C to give 1,7-bis(4-hydroxybenzyl)-1,4,7,10-tetraazacyclododecane (1). Results: The prepared ligand 1 was fully characterized by $^1H,\;^{13}C$ NMR, and mass spectrometer. The synthesized ligand was reacted with copper chloride and copper perchlorate to give copper complexes $[Cu(1)]^{2+}2(CIO_4^-)\;and\;[Cu(1)Cl]^+Cl^-$ which were confirmed by high-resolution mass (FAB). Conclusion: We successfully synthesized a cyclen derivative of which two phenol groups are located on trans position of N-atoms. And, two Cu(ll) complexes of +2 and +1 overall charge, were prepared as a potential PET tracers for ER imaging.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.729-733
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• 2014

Laminaria japonica roots have not been used practically in Korea. In this study, in order to promote the use of these by-products, the anti-inflammatory activity of an ethanol extract of Laminaria japonica root (LJREE) was investigated using a lipopolysaccharide (LPS) to induce an inflammatory response in RAW 264.7 cells. To examine the potential anti-inflammatory effects of LJREE, levels of nitric oxide (NO) and pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and interleukin-$1{\beta}$ (IL-$1{\beta}$), and cell proliferation were measured. We found that NO levels decreased in a dose-dependent manner, the production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed, and the production of IL-$1{\beta}$ was inhibited over 30% after treatment with $100{\mu}g/mL$ LJREE. In conclusion, the proliferation of RAW 264.7 cells, measured by MTT assay, confirmed that LJREE may have significant effects on inflammatory factors without any cytotoxicity, making it a potential anti-inflammatory agent.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.270-279
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• 2005

It is important to understand and evaluate the environmental impacts of rice cultivation for developing environmentally-friendly agriculture because rice is main crop in Korea and rice cultivation have both functions of water pollution and purification with environmental and cultivation conditions. This paper presents the evaluation of nitrogen impact by rice cultivation on water system. A simple protocol was proposed to assess the potential amount of nitrogen outflow from paddy field and most of parameters affect on the nitrogen outflow from paddy field such as the amount of fertilizer application, water balance, the quality and quantity of irrigation water, soil properties, nitrogen turnover in the soil and cultivation method were considered. To develop the protocol, coefficients for parameters affected nitrogen turnover and outflow were gotten and summarized by comparison and analysis of all possible references related, and by additional experiments at field and laboratory. And potential amount of nitrogen input and output by water in paddy field were estimated with the protocol at the conditions of the nitrogen contents of irrigation water, amount of fertilizer application, and irrigation methods. Where irrigation water was clean, below 1.0 mg $L^{-1}$ of nitrogen concentration, rice cultivation polluted nearby watershed. At the conditions of 2.0 mg $L^{-1}$ of nitrogen concentration, 110 kg $ha^{-1}$ of nitrogen fertilizer application and flooding irrigation, rice cultivation had water pollution function, but it had water purification function with intermittent irrigation. At the conditions of 3.0 mg $L^{-1}$ of nitrogen concentration and 110 kg $ha^{-1}$ of nitrogen fertilizer application, rice cultivation had water purification function, but that had water pollution function with 120 kg $ha^{-1}$ of nitrogen application. Where irrigation water was polluted over 6.0 mg $L^{-1}$ of nitrogen, it was evaluated that rice cultivation had water purifying effect, even though the amount of nitrogen application was 120 kg $ha^{-1}$.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.106-114
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• 2020

The development of transportation and the expansion of the pet market has become the main causes of the increase in the cross-border migration of non-native species. Moreover, recent sales over the Internet were a factor that has promoted pet trades. While the import of non-native species has been steadily increasing in the Republic of Korea, it is not clear how these imported species are traded and how large the trade is. Considering that most of the non-native species found in the wild are the results of release by humans understanding the present situation of pet trades can identify potential non-native species that can enter the wild. This study surveyed the number of species, frequency, and prices of non-native amphibians and reptiles sold in 25 online pet shops from January 22 to February 10, 2019. The results of the survey showed that a total of 677 species of non-native amphibians and reptiles were sold, and the Squamata group accounted for the largest part of them at 65.4% (443 species). The number of non-native amphibians and reptiles sold in online pet shops in 2019 was 2.1 times larger than the 325 species officially imported in 2015. The non-native amphibians and reptiles sold in most pet shops were Litoria caerulea (21 shops) and Correlophus ciliatus (24 shops). The lowest price for non-native amphibians and reptiles was 3,000 won, and the highest price was 100 million won for Rhacodactylus leachianus of Squamata. Among the non-native amphibians and reptiles sold in online pet shops, 11 species were found in the wild and were sold at relatively low prices. We confirmed that Mauremys reevesii, an endangered species class II and natural monument no. 453, and American bullfrogs (albino), an ecosystem disturbing species, were being sold in online pet shops. Moreover, 21.6% of the 677 non-native amphibians and reptiles sold in online pet shops were species designated as CITES. The results of this study can be the important reference data for understanding the status of non-native amphibians and reptiles that are imported and sold in Korea and evaluating and predicting the potential for them to enter the wild.

• Management & Information Systems Review
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• v.3
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• pp.287-316
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• 1999

Cyberspace permits us to more beyond traditional face-to-face, mail and telephone surveys, yet still to examine basic issues regarding the quality of data collection: sampling, questionnaire design, survey distribution, means of response, and database creation. This article address each of these issues by contrasting and comparing traditional survey methods(Paper-and-Pencil) with Internet or Personal Computer networks-mediated (Screen-and-Keyboard) survey methods also introduces researchers to this revolutionary and innovative tool and outlines a variety of practical methods for using the Internet or Personal Computer Networks. The revolution in telecommunications technology has fostered the rapid growth of the Internet all over the world. The Internet is a massive global network and comprising many national and international networks of interconnected computers. The Internet or Personal Computer Networks could be the comprehensive interactive tool that will facilitate the development of the skills. The Internet or Personal Computer Networks provides a virtual frontier to expand our access to information and to increase our knowledge and understanding of public opinion, political behavior, social trends and lifestyles through survey research. Comparable to other technological advancements, the Internet or Personal Computer Networks presents opportunities that will impact significantly on the process and quality of survey research now and in the twenty-first century. There are trade-offs between traditional and the Internet or Personal Computer Networks survey. The Internet or Personal Computer Networks is an important channel for obtaining information for target participants. The cost savings in time, efforts, and material were substantial. The use of the Internet or Personal Computer Networks survey tool will increase the quality of research environment. There are several limitations to the Internet or Personal Computer Network survey approach. It requires the researcher to be familiar with Internet navigation and E-mail, it is essential for this process. The use of Listserv and Newsgroup result in a biased sample of the population of corporate trainers. However, it is this group that participates in technology and is in the fore front of shaping the new organizations of interest, and therefore it consists of appropriate participants. If this survey method becomes popular and is too frequently used, potential respondents may become as annoyed with E-mail as the sometimes are with mail survey and junk mail. Being a member of the Listserv of Newsgroup may moderate that reaction. There is a need to determine efficient, effective ways for the researcher to strip identifiers from E-mail, so that respondents remain anonymous, while simultaneously blocking a respondent from responding to a particular survey instrument more than once. The optimum process would be on that is initiated by the researcher : simple, fast and inexpensive to administer and has credibility with respondents. This would protect the legitimacy of the sample and anonymity. Creating attractive Internet or Personal Computer Networks survey formats that build on the strengths of standardized structures but also capitalize on the dynamic and interactive capability of the medium. Without such innovations in survey design, it is difficult to imagine why potential survey respondents would use their time to answer questions. More must be done to create diverse and exciting ways of building an credibility between respondents and researchers on the Internet or Personal Computer Networks. We believe that the future of much exciting research is based in the Electronic survey research. The ability to communicate across distance, time, and national boundaries offers great possibilities for studying the ways in which technology and technological discourse are shaped. used, and disseminated ; the many recent doctoral dissertations that treat some aspect of electronic survey research testify to the increase focus on the Internet or Personal Computer Networks. Thus, scholars should begin a serious conversation about the methodological issues of conducting research In cyberspace. Of all the disciplines, Internet or Personal Computer Networks, emphasis on the relationship between technology and human communication, should take the lead in considering research in the cyberspace.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.223-243
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• 1989

The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.66-72
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• 2009

The detection methods are required to monitor and diagnose the abnormality on the insulation condition inside a gas-insulated switchgear (GIS). Due to a good sensitivity to the products decomposed by partial discharges (PDs) in $SF_6$ gas, the development of a SWNT gas sensor is actively in progress. However, a few numerical studies on the diffusion mechanism of the $SF_6$ decomposition products by PD have been reported. In this study, we modeled $SF_6$ decomposition process in a chamber by calculating temperature, pressure and concentration of the decomposition products by using a commercial CFD program in conjunction with experimental data. It was assumed that the mass production rate and the generation temperature of the decomposition products were $5.04{\times}10^{-10}$ [g/s] and over 773 K respectively. To calculate the concentration equation, the Schmidt number was specified to get the diffusion coefficient functioned by viscosity and density of $SF_6$ gas instead rather than setting it directly. The results showed that the drive potential is governed mainly by the gradient of the decomposition concentration. A lower concentration of the decomposition products was observed as the sensors were placed more away from the discharge region. Also, the concentration increased by increasing the discharge time. By installing multiple sensors the location of PD is expected to be identified by monitoring the response time of the sensors, and the information should be very useful for the diagnosis and maintenance of GIS.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.203-207
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• 2009

The concern of seriousness and harmful effects of environmental pollution is rising by the various water pollutions, appearances of new micro-noxious substances and increase of sustainable pollutants. The method is suggested that can effectively increase the removal of organic substances and several pollutants using a coagulation process. The experiment for characteristics of $ZrSiO_4$ (zirconium silicate) as a coagulation-aid was carried out for application to coagulation process with domestic wastewater and lake water, and the removal rate of the organic substances depending on a dosage was evaluated by PDA (Photometric Dispersion Analyzer) in this study. Zeta-potential of zirconium silicate solution was -32.22 mv at pH 7 and the lower negative(-) charge was detected in the more acidic conditions. Absorbance on $UV_{254}$ presented higher when zirconium silicate was added than in a domestic wastewater itself. Besides, the results by PDA experiment represented that injection of zirconium silicate could promote growing of floc. Tests for coagulation process were conducted by three ways which are pre-injection, co-injection and post-injection of zirconium silicate with alum. Accordingly, removal efficiency of organic substances increased over 15% in co-injection than in using of alum as a sole reagent. When a 20 mg/L of alum was used with a 10 mg/L of zirconium silicate, the removal efficiency was high up to 90%. Removal efficiency of $COD_{Cr}$ was improved more than 15% in case of dosage of coagulant either PAC (Poly aluminium chloride) or PACS (Poly aluminium chloride Silicate) together with zirconium silicate. As a result, the removal efficiency of $COD_{Cr}$ were 5~10% higher in a co-injection of zirconium silicate with a coagulant than a pre-injection and a post-injection but it of soluble substances was lower in a co-injection.

• The Journal of Art Theory & Practice
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• no.5
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• pp.43-80
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• 2007

PASKYULA was formed in September, 1923 through the union of artists involved in two art groups: Kim Ki-Jin, Kim Bok-Jin, Yeon Hak-Nyeon who had previously participated in the ToWolHoi, and Park Young-Hi, Lee Sang-Hwa, An Seok-Ju, former members of the BaeckJo. After its founding, the PASKYULA artists had been searching for the social function of art to reform the harsh reality of Minjung and the nation with criticism toward society as well as art world. Their art theory for MinJung could grow relatively ease in relation to changing social and political conditions in the early 1920s. In August, 1925, PASKYULA organized the Korea Artista Proletaria Federatio with the YeomGunSa, and laid the groundwork for Proletariat art movement which was regularized in the late 1920s. From PASKYULA up to the early state of KAPF, the theory of art advocated by Kim Bok-Jin and An Seok-Ju could be summarized as "art for MinJung". At that time, widely ranging discourses on MinJung, however, was spawned in art theory, because many intellectuals-including artists and writers-begun to pay more attention to MinJung, who emerged as one of the social forces after the Samil Independent Movement. Sometimes, MinJung was construed as the target of enlightenment from a negative viewpoint. On the other hand, several intellectuals under the influence of individualism asserted that the discussion itself on MinJung exerted an evil influence on art. In contrast of these cases, the PASKYULA artists including Kim Bok-Jin, An Seok-Ju perceived that MinJung had the potential to change society, and regarded them as "a creator of genuine civilization and art". In the PASKYULA artist's writings, the concept of MinJung was often overlapped with the meaning of the Choson nation suffering under colony. Although their concept of MinJung was transformed gradually into the proletariat as they were under the strong influence of socialism, it did not change that they grasped the realities of the whole Choson Peninsula through the proletarian consciousness. In the early state of PASKYULA, the methodology for social function of art was presented in a twofold manner. First of all, Kim Bok-Jin emphasized on the necessity of education to improve MinJung's way of life through art, and it was embodied by the organization of ToWol Art Workshop and public lecture. Also, he championed "the popularization of art", which was one of methods to distribute art to MinJung. According to the PASKYULA artists, art should be not art for art' sake but art for MinJung. That was why they advocated the convergence of art and MinJung's life. Especially Kim Bok-Jin affirmed a link between art and industry because he considered industry the field inextricably linked with MinJung's life. In this context, his idea could be read as the generalization and equalization within the framework of possession. Kim Bok-Jin thought that the social ramifications of capitalism deprived MinJung of their right to enjoy art, and emphasized the artist' social role to return the right to them. That is, the even distribution of art was mainly discussed than the contents of art in the half of 1920s. By 1925, the contents of art itself became an issue in the PASKYULA art theory, and it was based in realism. Kim Bok-Jin and An Seok-Ju insisted that art should be reflection of real life. At that time, realism acquired the representation of MinJung and the nation's realities not realistic style. In fact, the various Western art styles including Futurism, Constructivism, Cubism etc. were exploited in the PASKYULA's visual images. Western art, target of criticism on theory, was selectively adopted in the works which were produced by Kim Bok-Jin and An Seok-Ju. Kim Bok-Jin's MoonYeUnDong cover design was conceived of as the example in which Western art was adopted with it's ideology under the influence of MAVO, while Western art shown in An Seok-Ju's illustrations served as a decorative function in many cases. Especially, An Seok-Ju attempted the various styles of Western art simultaneously, which may be seen as representing that PASKYULA did not have a firm ideology for their style. Also, it can be read as showing his hasty zeal to overcome Western art rapidly. The wish to establish "art for MinJung" as soon as possible was accompanied with the will to jump over the all steps of Western art though it was superficial. This aspiration of PASKYULA was expressed through the mass media, which had the potential for communicating to MinJung. At this point, there was a significant disparity between PASKYULA and another art groups in the first half of 1920s. However, the PASKYULA's method on the basis of the mass media could not but have a certain limitation because of the medium's properties. Nevertheless, PASKYULA' attempts may be considered to be valuable in sense that they expended the boundaries of Korean modern art into the commercial art questioning the matter of the distribution for art.