• 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.

• Asia pacific journal of information systems
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• v.18 no.1
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• pp.25-51
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• 2008

Researchers have been continuously interested in the adoption of information technology (IT) since it is of great importance to the information systems success and it is also an important stage to the success. Adoption alone, however, does not ensure information systems success because it does not necessarily lead to achieving organizational or individual objectives. When an organization or an individual decide to adopt certain information technologies, they have objectives to accomplish by using those technologies. Adoption itself is not the ultimate goal. The period after adoption is when users continue to use IT and intended objectives can be accomplished. Therefore, continued IT use in the post-adoption period accounts more for the accomplishment of the objectives and thus information systems success. Previous studies also suggest that continued IT use in the post-adoption period is one of the important factors to improve long-term productivity. Despite the importance there are few empirical studies focusing on the user behavior of continued IT use in the post-adoption period. User behavior in the post-adoption period is different from that in the pre-adoption period. According to the technology acceptance model, which explains well about the IT adoption, users decide to adopt IT assessing the usefulness and the ease of use. After adoption, users are exposed to new experiences and they shape new beliefs different from the thoughts they had before. Users come to make decisions based on their experiences of IT use whether they will continue to use it or not. Most theories about the user behaviors in the pre-adoption period are limited in describing them after adoption since they do not consider user's experiences of using the adopted IT and the beliefs formed by those experiences. Therefore, in this study, we explore user's experiences and beliefs in the post-adoption period and examine how they affect user's intention to continue to use IT. Through deep literature reviews on the construction of subjective beliefs by experiences, we draw three meaningful constructs which theoretically have great impacts on the continued use of IT: perceived habit, confirmation, and computer self-efficacy. Then, we examine the role of the subjective beliefs on the cognitive/affective attitudes and intention to continue to use that IT. We set up a research model and conducted survey research. Since IT use implies interactions among a user, IT, and a task, we carefully selected the sample of users using same/similar IT to perform same/similar tasks, to exclude unwanted influences of other factors than subjective beliefs on the IT use. We also considered that the sample of users were able to make decisions to continue to use IT volitionally or at least quasi-volitionally. For each construct, we used measurement items recognized for reliability and widely used in the previous research. We slightly modified some items proper to the research context and a pilot test was carried out for forty users of a portal service in a university. We performed a full-scale survey after verifying the reliability of the measurement. The results show that the intention to continue to use IT is strongly influenced by cognitive/affective attitudes, perceived habits, and computer self-efficacy. Confirmation affects the intention to continue indirectly through cognitive/affective attitudes. All the constructs representing the subjective beliefs built by the experiences of IT use have direct and/or indirect impacts on the intention of users. The results also show that the attitudes in the post-adoption period are formed, at least partly, by the experiences of IT use and newly shaped beliefs after adoption. The findings suggest that subjective beliefs built by the experiences have deep impacts on the continued use. The results of the study signify that while experiencing IT in the post-adoption period users form new beliefs, attitudes, and intentions which may be different from those of the pre-adoption period. The results of this study partly demonstrate that the beliefs shaped by the behaviors, those are the experiences of IT use, influence users' attitudes and intention. The results also suggest that behaviors (experiences) also change attitudes while attitudes shape behaviors. If we combine the findings of this study with the results of the previous research on IT adoption, we can propose a cycle of IT adoption and use where behavior shapes attitude, the attitude forms new behavior, and that behavior shapes new attitude. Different from the previous research, the study focused on the user experience after IT adoption and empirically demonstrated the strong influence of the subjective beliefs formed in the post-adoption period on the continued use. This partly confirms the differences between attitudes in the pre-adoption and in the post-adoption period. Users continuously change their attitudes and intentions while experiencing (using) IT. Therefore, to make users adopt IT and to make them use IT after adoption is a different problem. To encourage users to use IT after adoption, experiential variables such as perceived habit, confirmation, and computer self-efficacy should be managed properly.

• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.91-114
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• 1981

This research was carried out from July to August, 1981, to analyse the true state of management, the skill of production, the structure of consciousness about the selected 294 poultry$.$farms, and to know about their bottlenecks and suggestions. The results obtained were as follows: 1. As for manager's ages, 31 to 45 years old men rate was 67.76%. upper 50years old men 15.94%. 2. 79.9% of farm omen possess attainments equal to or higher than those of upper secondary school graduates. 3. In poultry farming career of the investigated person, layer chicken industry was longer than broiler. 4. Occupations of farm owners before. doing poultry farming were farmers(32.35%), company employees, civil servants and soldiers, etc. 5. 58.62% of the person ran only poultry farming and the rest of them held the additional office of a farmer and a public officer. 6. There were many people who made a speciality of poultry farming holding additional jobs as dairy farming, cultivating crops, gardening, etc. 7. 42.35% of the person began poultry farming with under 1,000 layer chickens. And the rate of the ones with 1,000-2,000 broilers for the first time consisted 40.95% 8. Present breeding scale was that the rate of the farmers having 5,000-10,000 layer chickens was 37.13% and the ones having 5,000-10,000 broilers 38.32%. 9. The rate of the person supplying self-labor was 23.16%, the person having 1.3 employees 51.47% and the ones having under 20 employees 1.47%. 10. 74.26% of the poultry farms used very good quality of baby chicks. 11. The rate of the farms which used chicken feed making the point of the quality of it was 65.47% and the ones which bought it on credit 26.62%. 12. 65.47% bought feed directly from factories and 26.62% bought it from commercial agents. 13. The rate of the layer chicken farms paying for feed in cash was 19.39% and the broiler farms 32.74%. Most of the farms bought feed on credit by 30-60 days. 14. They bought the medicine for chicken from animal drug stores or veterinary hospitals. 15. The rate of the person posting up accounts roughly was 47.52% and that of the ones doing them detaily was 43.57%, 40% did not do them because of bother and only 21.22% had their own cashbooks.

• Korean Security Journal
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• no.2
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• pp.259-289
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• 1999

The Security Industry has dynamic working conditions. So this study intends to find the advisable direction for the reduction of accidents. To achieve the aim, the investigation of documents and the examinations of actual proofs have been done to figure the theoretical background and to see the basic knowledge of security industry. The questionnaire was composed of two question sheets to search real data and actual proofs, with making targets of pure security organization and personnel. The one consists of 9 questions to find the scale and extent of security organizations and the population and character of security personnel, and the other 25 questions in 3 major areas to analyze the causes, the frequency rates, the factors, and the condition of accidents. The period of survey was July 15th to October 15th in 1997 by mail/telephone/interview. The questionnaires were efficiently returned from 102 different organizations including the public security groups of Seoul Metropolitan Police Bureau and so on, with the information of 8,222 persons having worked for Korean Security Industry in 1996. So being based on the reality, some meaningful facts were found, and were compared with the national statistics of the Government. This study is made up of 5 chapters : in the 1st chapter the motivation, the object, the method, the direction and the limitation of the approach were presented ,in the 2nd chapter the theoretical background were inferred ; in the 3rd chapter the collected data of accidents in Korean Security Industry were analyzed and explained on the base of the questionnaires , in the 4th chapter the advisable facts connected with preventing accidents were mentioned ; in the last the conclusion were stated. With the replies of 102 different organizations including the information of 8,222 persons in 1996, the main facts found or analyzed through this study are as follows. Firstly, accident is an unpredictable and occasional event. It occurs to man and/or thing, but the frequency rate of accidents in Korean Government and other Institutes has been calculated and evaluated only in the point of the accident related with man. Secondly, the factors of accidents are firstly relevant to the way preventing accidents in Security Industry in Korea. However the frequency rate is academically calculated and evaluated by at once man(population) and hour(time). But the Government has done the rate only by man(population). This can be improper and inaccurate rates. Thirdly, the confused concept of security is used in Korean Government, academic society, corporation and so on. Therefore the detailed formation of the concept is needed for the development of Security Industry in Korea. Fourthly, security organizations can be classified into 'public security(public law enforcement)' and 'private security' according to its identification, and furthermore 'private security' can be divided into 'facilities-guard service', 'body-guard service', and 'patrol service' according to its major role. Fifthly, in the viewpoint of the number of both organization and population,'facilities-guard service' is centered in Korean 'private security'. According to the analyzed results of the questionnaires in this study, the frequency rate of accidents of Korean Security Industry is 0.43(%) totally in 1996 : 'facilities-guard service' 0.54(%), 'body-guard service' 0.12(%), and 'patrol service' 0.21(%) in 'private security', and 'public security' 0.20(%). With regard to the accident frequency rate of organization and population, 'facilities-guard service' is the highest. The accident frequency rate of population in 'facilities-guard service' organization ranges dispersively from 0.20(%) to 11.11(%). Sixthly, the accidented rate of workers having serviced for under one year is 57.6(%). This can mean that the main factor of accidents in Korean Security Industry is the lack of role-understanding and training/education. And another factor can be found on the time of accident occurrence. Many accidents have been occurred on the relaxed points like as just after lunch and morning rush-hour. Lastly, the major advisable facts related to preventing accidents are as follows : The workers who are over fifty years old in 'facilities-guard service' organization need to be educated for preventing accidents ; It is desirable that the training and education to prevent accidents should be practiced in the time of pre-service ; As the style of accidents and the age of the accidented are not same according to major service area('public security' and 'private security' : 'facilities-guard service', 'body-guard service', and 'patrol service'), the plans to prevent accidents must be different and various. However fracture and bruise are general accidents in Korean Security Industry ; Workers must care about traffic accident and violent fall ; It seems that the grouped working with other two persons will reduce accident occurrence possibility rather than individually single working.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.86-92
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• 2008

This study was conducted to determine removal effect on phytoplankton (chlorophyll-${\alpha}$ as whole algae) and cyanobacteria by a fish Pseudorasbora parva and macroinvertebrate Palaemon paucidens in September 2006. Three treatments with 25 (T1), 50 (T2) and 100 (T3) individuals along with control (C1, no input fish), and two treatments with 25 (T4) and 50 (T5) individuals along with control (C1) were made for fish and macroinvertebrate, respectively. The initial concentrations of chlorophyll-${\alpha}$ $(Chl_i)$ in each 10L test tank were set up for the levels of $95{\sim}100{\mu}g\;L^{-1}$ and the daily values were monitored in the test tank during 7 days. In the lab tests, P. parva did not show Chl-${alpha}$ removal effect; the removal rate of Chl-${alpha}$ for P. parva was -58% in T1, -56% in T2, and 61% in T3 during the test period. In contrast, P. paucidens. in the treatments of T4 and T5 removed the phytoplankton effectively and the removal effect were appeared to be 33% and 22%, respectively. Also, P. paucidens showed high feeding efficiency in the removal of cyanobacteria. The levels of cyanobacteria were greatly lowed from 6,048 to 927 cells $mL^{-1}$ in T4 and from 6,539 to 1,053 cells $mL^{-1}$ in T5, resulting in 85% and 84% in the removal effect, respectively. Our results for biomanipulation tests suggest that P. paucidens may be used as a potential candidate organism for algae control in spite of the preliminary results by laboratory tests.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.477-486
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• 2017

In this study, we analyze precise seabed geomorphology and conditions for comparing the nearshore areas of the Dongdo(East Island) and the Seodo(West Island) using detailed bathymetry data and seafloor backscattering images, in Dokdo, the East Sea. We have been obtained the detailed bathymetry data and the seafloor backscattering data. The survey range is about $250m{\times}250m$ including land of islets to the nearshore areas of the southern part of the Dongdo and the Seodo. As a result of bathymetry survey, the southern area of the Dongdo(~50 m) is deeper than the Seodo(~30 m) in the water depth. The survey areas are consist of extended bedrocks from land of the Dongdo and the Seodo. The underwater rock region of the Seodo is larger than the Dongdo. In spite of similar extended rocks features from islets, there are some distinctive seabed characteristics between the southern nearshore areas of the Dongdo and the Seodo. The Talus-shaped seafloor environment formed by gravel and underwater rocks originating from the land of the Dongdo is up to about 15 m depth. And the boundary line of between extended bedrocks and seabottom is unclear in the southern nearshore of the Dongdo. On the other hand, the southern coast of the Seodo is characterized by relatively large scale underwater rocks and evenly distributed sediments, which clearly distinguish the boundary of between extended bedrocks and seafloor. This is because the tuff layers exposed to the coastal cliffs of the Dongdo are weak against weathering and erosion. It is considered that there are more influences of the clastic sediments carried from the land of the Dongdo compared with the Seodo. Particularly, the land of the Dongdo has been undergoing construction activities. And also a highly unstable ground such as faults, joints and cracks appears in the Dongdo. In previous study, there are dissimilar features of the massive tuff breccia formations of the Dongdo and the Seodo. These conditions are thought to have influenced the different seabed characteristics in the southern nearshore areas of the Dongdo and the Seodo.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.1
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• pp.51-60
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• 2000

The purpose of this study was to compare the microleakage at the interface of cast post and tooth according to the type of cement. Forty anterior teeth with single root were used. The teeth were cut 2 mm coronal from the cementoeamel junction and chamfer finish line was made on 1 mm coronal from the cementoeamel junction. After the routine endodontic treatment, post space was prepared using #5.5 Parapost drill to a depth of 7 mm. After the pick up impression, core building was made to 3 mm of clinical crown with burnout wax, then post and core was cast with nonprecious metal. The teeth were divided into four groups of ten each. In Group I, post and core were cemented with Fleck's(Zinc phosphate cement) In Group II, post and core were cemented with Fuji I(Glass ionomer cement) In Group III, post and core were cemented with Superbond C & B(Composite resin cement) In Group IV, post and core were cemented with Panavia 21(Composite resin cement) All cemented teeth were stored in normal saline at $37^{\circ}C$ for 7 days and thermocycled from $5^{\circ}C$ to $55^{\circ}C$ for 500 cycles with a dwell time of 30 seconds. After thermocycling, teeth were immersed in 1% Basic fuchsin dye for 48 hours. All 40 teeth were then embedded in the epoxy resin and cut buccolingually with a cutting instrument. The degree of penetration of dye at interface was graded on a scale of 0 to 4 using a stereomicroscope at 25 to 40 times magnification. Through the findings of this study, the following conclusion were obtained. 1. All the groups showed the microleakage at the interface of cast post core and tooth. 2. Group I showed the highest microleakage score among the groups with a significant difference(p<0.05). 3. Group II showed higher microleakage score than Group III and Group IV with a significant difference(p<0.05). 4. Group IV showed the lowest microleakage score but there were no significant difference with Group III(p>0.05).

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.3-54
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• 2013

Nowadays, major advanced countries in aviation technology are putting their effort to develop commercial and civil Unmanned Aircraft System(UAS) due to its highly promising market demand in the future. The market scale of commercial and civil UAS is expected to increase up to approximately 8.8 billon U.S. dollars by the year 2020. The usage of commercial and civil UAS covers various areas such as remote sensing, relaying communications, pollution monitoring, fire detection, aerial reconnaissance and photography, coastline monitoring, traffic monitoring and control, disaster control, search and rescue, etc. With the introduction of UAS, changes need to be made on current Air Traffic Management Systems which are focused mainly manned aircrafts to support the operation of UAS. Accordingly, the legislation for the UAS operation should be followed. Currently, ICAO's Unmanned Aircraft System Study Group(UASSG) is leading the standardization process of legislation for UAS operation internationally. However, some advanced countries such as United States, United Kingdom, Australia have adopted its own legislation. Among these countries, United States is most forth going with President Obama signing a bill to integrate UAS into U.S. national airspace by 2015. In case of Korea, legislation for the unmanned aircraft system is just in the beginning stage. There are no regulations regarding the operation of unmanned aircraft in Korea's domestic aviation law except some clauses regarding definition and permission of the unmanned aircraft flight. However, the unmanned aircrafts are currently being used in military and under development for commercial use. In addition, the Ministry of Land, Infrastructure and Transport has a ambitious plan to develop commercial and civil UAS as Korea's most competitive area in aircraft production and export. Thus, Korea is in need of the legislation for the UAS operation domestically. In this regards, I personally think that Korea's domestic legislation for UAS operation will be enacted focusing on following 12 areas : (1)use of airspace, (2)licenses of personnel, (3)certification of airworthiness, (4)definition, (5)classification, (6)equipments and documents, (7)communication, (8)rules of air, (9)training, (10)security, (11)insurance, (12)others. Im parallel with enacting domestic legislation, korea should contribute to the development of international standards for UAS operation by actively participating ICAO's UASSG.

• Journal of Energy Engineering
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• v.29 no.2
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• pp.68-78
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• 2020

According to the new climate change agreement, technology development to reduce greenhouse gases is actively conducted worldwide, and research on energy efficiency improvement in the field of power generation and transmission and distribution is underway [1,2]. Economic analysis of the operation method of storing and supplying surplus electricity using energy storage devices, and using energy storage devices as a frequency adjustment reserve power in regional cogeneration plants has been reported as the most profitable operation method [3-7]. Therefore, this study conducted an economic analysis for the installation of energy storage devices in the combined heat and power plant in the Czech Republic. The most important factor in evaluating the economics of battery energy storage devices is the lifespan, and the warranty life is generally 10 to 15 years, based on charging and discharging once a day. For the simulation, the ratio of battery and PCS was designed as 1: 1 and 1: 2. In general, the primary frequency control is designed as 1: 4, but considering the characteristics of the cogeneration plant, it is set at a ratio of up to 1: 2, and the capacity is simulated at 1MW to 10MW and 2MWh to 20MWh according to each ratio. Therefore, life was evaluated based on the number of cycles per year. In the case of installing a battery energy storage system in a combined heat and power plant in the Czech Republic, the payback period of 3MW / 3MWh is more favorable than 5MW / 5MWh, considering the local infrastructure and power market. It is estimated to be about 3 years or 5 years from the simple payback period considering the estimated purchase price without subsidies. If you lower the purchase price by 50%, the purchase cost is an important part of the cost for the entire lifetime, so the payback period is about half as short. It can be, but it is impossible to secure profitability through the economy at the scale of 3MWh and 5MWh. If the price of the electricity market falls by 50%, the payback period will be three years longer in P1 mode and two years longer in P2 and P3 modes.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.2
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• pp.90-94
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• 2013

Objective: To evaluate the efficacy of earlier oocyte retrieval in IVF patients with a premature LH surge on hCG day. Methods: One hundred forty IVF patients (164 cycles) with premature LH surge on hCG day were included, retrospectively. We divided them into 2 study groups: LH surge with timed ovum pick-up (OPU) 36 hours after hCG injection (group B, 129 premature cycles), and LH surge with earlier OPU within 36 hours after hCG injection (group C, 35 cycles). Control groups were tubal factor infertility without premature LH surge (group A, 143 cycles). Results: The mean age (year) was statistically higher in group C than in groups A or B ($38.2{\pm}5.4$ vs. $36.2{\pm}4.2$ vs. $36.8{\pm}4.9$, respectively; p=0.012). The serum LH levels (mIU/mL) on hCG day were significantly higher in group B and C than in group A ($22.7{\pm}14.9$ vs. $30.3{\pm}15.9$ vs. $3.2{\pm}2.9$, respectively; p>0.001). Among groups A, B, and C, 4.9%, 31.7%, and 51.4% of the cycles, respectively, had no oocytes, and the overall rates of cycle cancellation (OPU cancellation, no oocyte, or no embryos transferrable) were 15.4%, 65.9%, and 74.3%, respectively. The fertilization rate (%) was significantly higher in group B than in group C ($73.2{\pm}38.9$ vs. $47.8{\pm}42.9$, p=0.024). The clinical pregnancy rate was significantly higher in group C than in groups A and B (44.4% vs. 27.3% vs. 9.1%, respectively, p=0.021). However, the miscarriage rate was also higher in group C than in group B (22% vs. 0%, respectively, p=0.026). Conclusion: Earlier OPU may not be effective in reducing the risk of cycle cancellation in patients with premature LH surge on hCG day. A larger scale study will be required to reveal the effectiveness of earlier ovum retrieval with premature LH surge.