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Relationship between Divergent Thinking in Mathematical and Non-Mathematical Situations -Based on the TTCT; Figural A and the MCPSAT- (수학적 상황과 비수학적 상황에서의 확산적 사고의 관계 연구 - TTCT의 도형검사와 MCPSAT를 중심으로 -)

  • Hwang, Dong-Jou;Lee, Kang-Sup;Seo, Jong-Jin
    • Journal of Gifted/Talented Education
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    • v.15 no.2
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    • pp.59-76
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    • 2005
  • We examined the relations between the score of the divergent thinking in mathematical (Mathematical Creative Problem Solving Ability Test; MCPSAT: Lee etc. 2003) and non-mathematical situations (Torrance Test of Creative Thinking Figural A; TTCT: adapted for Korea by Kim, 1999). Subjects in this study were 213 eighth grade students(129 males and 84 females). In the analysis of data, frequencies, percentiles, t-test and correlation analysis were used. The results of the study are summarized as follows; First, mathematically gifted students showed statistically significantly higher scores on the score of the divergent thinking in mathematical and non-mathematical situations than regular students. Second, female showed statistically significantly higher scores on the score of the divergent thinking in mathematical and non-mathematical situations than males. Third, there was statistically significant relationship between the score of the divergent thinking in mathematical and non-mathematical situations for middle students was r=.41 (p<.05) and regular students was r=.27 (p<.05). A test of statistical significance was conducted to test hypothesis. Fourth, the correlation between the score of the divergent thinking in mathematical and non-mathematical situations for mathematically gifted students was r=.11. There was no statistically significant relationship between the score of the divergent thinking in mathematical and non-mathematical situations for mathematically gifted students. These results reveal little correlation between the scores of the divergent thinking in mathematical and non-mathematical situations in both mathematically gifted students. Also but for the group of students of relatively mathematically gifted students it was found that the correlations between divergent thinking in mathematical and non-mathematical situations was near zero. This suggests that divergent thinking ability in mathematical situations may be a specific ability and not just a combination of divergent thinking ability in non-mathematical situations. But the limitations of this study as following: The sample size in this study was too few to generalize that there was a relation between the divergent thinking of mathematically gifted students in mathematical situation and non-mathematical situation.

Experimental renal artery embolization with iohexol-ethanol and barium-ethanol in dogs (개에서 iohexol-ethanol 및 barium-ethanol을 이용한 실험적 신동맥 색전술)

  • Hwang, Guk-jin;Chang, Dongwoo;Seo, Minho;Jung, Joohyun;Choi, Mincheol;Yoon, Junghee
    • Korean Journal of Veterinary Research
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    • v.41 no.3
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    • pp.429-436
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    • 2001
  • The present study was performed to investigate the effect of iohexol-ethanol mixture and barium-ethanol mixture on the induction of transcatheter renal artery embolization in healthy 18 dogs, which were divided into two groups of 9 dogs and the 9 dogs were divided into 3 subgroups of 3 dogs. The renal artery embolization was undertaken unilaterally with the dose of 1.5, 2.0, and 3.0 ml/kg iohexol-ehtanol mixture and with the dose of 0.2, 0.4, and 0.8 ml/kg barium-ethanol mixture. And serum chemistry on 0, 1,3, 7, and 14 days, intravenous pyelography on 7days, angiography on 14 days, and histopathology on 14 days were evaluated. Serum BUN and creatinine concentration of two groups with iohexol-ethanol mixture and barium-ethanol mixture administration were mildly increased a t 1 day after injection of embolic materials and then returned to baseline. No significant changes in BUN and creatinine levels occurred in any of dogs. In all dogs with the dose of 1.5 ml/kg iohexol-ethanol mixture, the renal arteries were not embolized. All dogs with the dose of 3.0 ml/kg died. In all dogs with the dose of 2.10 ml/kg, the treated arteries were completely occluded. In barium-ethanol mixture administered group, the renal artery in one dog with the dose of 0.2 ml/kg was not embolized. In all dogs with the dose of 0.8 ml/kg, the renal arteries were completely embolized, but loac overembolization occured in two dogs. All animals with the dose of 0.4 ml/kg had effective embolization and no evidence of radiopaque barium opacity in systemic arteries distal to the renal-artery was found. All embolized kidneys were shrunk and decreased in size in gross examination and were shown diffuse necrosis in histopathologic examination. In the present study, renal arteries were embolized with the dose of 2.0 ml/kg iohexol-ethanol mixture or 0.4 ml/kg barium-ethanol mixture. And it is considered that the dose had a satisfactory embolic effect.

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A Study on the Stiffness of CBA(Corner Block with Anchor Bolt) Joint in Knockdown Type Table Furniture (조립식(組立式) 탁자(卓子)의 CBA접합부(接合部) 강성(剛性)에 관(關)한 연구(硏究))

  • Chung, Woo-Yang;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.17 no.2
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    • pp.34-64
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    • 1989
  • Corner block with anchor bolt(CBA) joint method used in knock-down type table furniture manufacturing can reduce the packing and transporting cost. Unfortunately. it also has the disastrous defect to be loosend and unstable during the service life mainly due to fatigue and creep(repeated and prolonged loading). So 22 joint groups constructed were tested to evaluate the effect of some design factors related to the size of side rail(apron). block attachment to side rail. and the number of anchor bolt as well as the effect of the type of corner block(mitered type vs. rectangular type) Usable strength from the stiffness coefficients of each joint group were analysed with SPSS /PC+ and described as the criteria of CBA joint construction. The conclusions were as follows: The height of side rail(50, 75 and 100 mm) and the addition of polyvinyl acetate(PVAc) emulsion in the corner block attactment to side rail had the effect on raising the usable strength of CBA joint with remarkable high significance. And the effect of 2 - anchor bolts was also superior to that of 1 - bolt significantly. However. the thickness of side rail(22 mm vs. 25 mm) had no effect on the strengthening the table joint rigidity. Mitered type corner block joint appeared to he recommendable for CBA jointed table construction rather than the rectangular type one regardless of the method of block attachment to side rail. The best result identified from Duncan's multiple comparison was in the construction with 25 mm thick and 100 mm height of side rail fastened using 2 - anchor bolts in mitered type corner block. But it would be reasonable to use 22 mm thick & 75 mm high side rail and mitered corner block with PVAc emulsion & 2 bolts considering the productivity and production cost down in the MDF furniture manufacturing industries.

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Mutual Funds Trading and its Impact on Stock Prices (뮤추얼펀드의 자금흐름과 주식거래가 주가에 미치는 효과)

  • Kho, Bong-Chan;Kim, Jin-Woo
    • The Korean Journal of Financial Management
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    • v.27 no.2
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    • pp.35-62
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    • 2010
  • This paper examines the existence of the fund performance persistence and the smart money effect in Korean stock market and tests the flow-induced price pressure (FIPP) hypothesis, that is, fund flows affect individual stock returns and mutual fund performance. This paper also tests whether the FIPP effect can cause the performance persistence using the monthly returns and stock holdings data of 2,702 Korean mutual funds from January 2002 to June 2008. The empirical results indicate that the performance persistence exists significantly for a long time but the smart money effect does not. The hedge portfolio constructed by buying funds with the highest past 12 months performance and selling funds with the lowest past 12 months performance earns 0.11%~1.05% monthly abnormal returns, on average, in 3 years from portfolio formation month, but the hedge portfolio constructed by buying funds with the highest past net fund inflows and selling funds with the lowest past net fund inflows cannot earn positive monthly abnormal returns and the size of negative abnormal returns of the portfolio increase as time goes on. We find the evidence that the FIPP hypothesis is significantly supported. We first estimate the FIPP measure for each individual stock using the trading volume resulting from past fund flows and then construct the hedge portfolio by buying stocks with the highest FIPP measure and selling stocks with the lowest FIPP measure. That portfolio earns significantly positive abnormal return, 1.01% at only portfolio formation month and cannot earn significant abnormal returns after formation month. But, the FIPP effect cannot cause the performance persistence because, within the same FIPP measure group, funds with higher past performance still earn higher monthly abnormal returns than those with lower past performance by 0.08%~0.77%, on average, in 2 years. These results imply that the main cause of the performance persistence in Korean stock market is the difference of fund managers' ability rather than the FIPP effect.

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Study on the Planting Index of School Forest - The Case of Gyeonggido - (학교숲 조성지표에 관한 연구 - 경기도를 중심으로 -)

  • Jang, Dong-Su;Sin, Kwang-Sun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.6
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    • pp.12-18
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    • 2010
  • This study was carried out in order to propose a planning index for improved school forests in Gyeonggido. For the purpose of this study we selected 42 out of 75 school forests established during 2005 in Gyeonggido. All 42 school forests were surveyed and analyzed by frequency, cross tabulation, and group average analysis with SPSS 12.0 version. The present condition of the school forests was analyzed with in conjunction with items such as the surrounding environment, centralization, and locational characteristics as nominal points. Other items: trees, shrubs, pavement, fruit trees, transplantation, evergreen trees, and recreation facility content percentage were analyzed as a proportion point. After reviewing the literature and analyzing the present condition of school forests, we constructed a conceptual framework and formulated a hypothesis for this research. Data were obtained through a questionnaire, given to 98 students majoring in landscape architecture at Hankyong University in 2007. Results showed that the primary variables for tree health were soil compaction and the depth of soil filling. They were the most serious factors that deteriorate the health of trees. Based on the relationship between tree health and growing conditions, trees inside the school forest should be managed to provide more growing space and less abuse. The minimum area for trees inside the school forest for good growth conditions should be within the drip lines. We have found that the minimum percentage of tree content is 0.13, which means that more than 130 trees need to be planted over $1,000m^2$ green space. More than 3,580 shrubs need to be planted over $1,000m^2$ green space. The pavement area should be controlled to less than 19% of the total size of the school forest area. Finally, more than 39 trees out of 100 trees planted should be evergreen. The research results suggest that the construction planning index of Gyeonggido school forest be recommended in the planning and development process of the construction project carried out every year.

Characteristics and Survival of Genus Vibrio Isolated in the Intertidal Zone of the Yellow Sea near Kunsan (군산인근해역에서 분리동정된 Vibrio 속의 특성과 해수에서의 생존)

  • 왕혜영;이건형
    • Korean Journal of Environmental Biology
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    • v.17 no.4
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    • pp.439-448
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    • 1999
  • To investigate the population dynamics and survival of Genus Vibrio, population densities of aerobic saprophytic bacteria and Vibrio groups were measured 4 times in the intertidal waters of the Yellow Sea near Kunsan from November, 1997 to June, 1998. The distribution of heterotrophic bacteria during the survey periods by plate count and direct count method ranged from 1.2$\pm$0.6$\times$10$^3$~2.0$\pm$1.5$\times$10$^4$CFU ml­$^1$and from 6.0$\pm$4.0$\times$10$^{5}$ ~1.9$\pm$1.5$\times$10$^{7}$ cells ml­$^1$, respectively. Vibrio groups were distributed in the range of 1$\times$10 and 6$\pm$2.2$\times$10$^2$CFU ml­$^1$. The proportion of Vibrio groups to total heterotrophic bacteria was between 0.1 and 6% during the survey periods. A total of 51 isolates was obtained from TCBS agar plates and identified to species level by Biolog Identification System$^{TM}$. As a result, dominant genera were V, mediterranei, V aitguillarum, tr metschnikovii, and V. parahaemolyticus, and isolates were clustered into 26 groups based on the relatedness of average linkage clustering method at 70% level. As for the susceptibility of 51 isolates to 7 kinds of antibacterial agents (gentamicin, ampicillin, chlorarnphenicol, streptomycin, kanamycin, tetracycline, carbenicillin), 96% of isolates showed high resistance to more than one antibiotics and 65% of isolates contained a plasmid, of which size was observed greater than 12 kb, The number of cells of 3 tested strains (V. anguillarum, V. vulnificus, and V. metschnikovii) in filtered aged seawater decreased by approximately 1 to 5 orders of magnitude during 30-d incubation. In most cases, the numbers of cells decreased rapidly until day 3, then decreased slowly by day 30. The number of cells incubated at 15$^{\circ}C$ showed higher survival than those at 4$^{\circ}C$ and $25^{\circ}C$. These results may be considered for the basic supporting data in the risk assessment of vibriosis in summer.r.

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The Application of Operations Research to Librarianship : Some Research Directions (운영연구(OR)의 도서관응용 -그 몇가지 잠재적응용분야에 대하여-)

  • Choi Sung Jin
    • Journal of the Korean Society for Library and Information Science
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    • v.4
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    • pp.43-71
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    • 1975
  • Operations research has developed rapidly since its origins in World War II. Practitioners of O. R. have contributed to almost every aspect of government and business. More recently, a number of operations researchers have turned their attention to library and information systems, and the author believes that significant research has resulted. It is the purpose of this essay to introduce the library audience to some of these accomplishments, to present some of the author's hypotheses on the subject of library management to which he belives O. R. has great potential, and to suggest some future research directions. Some problem areas in librianship where O. R. may play a part have been discussed and are summarized below. (1) Library location. It is usually necessary to make balance between accessibility and cost In location problems. Many mathematical methods are available for identifying the optimal locations once the balance between these two criteria has been decided. The major difficulties lie in relating cost to size and in taking future change into account when discriminating possible solutions. (2) Planning new facilities. Standard approaches to using mathematical models for simple investment decisions are well established. If the problem is one of choosing the most economical way of achieving a certain objective, one may compare th althenatives by using one of the discounted cash flow techniques. In other situations it may be necessary to use of cost-benefit approach. (3) Allocating library resources. In order to allocate the resources to best advantage the librarian needs to know how the effectiveness of the services he offers depends on the way he puts his resources. The O. R. approach to the problems is to construct a model representing effectiveness as a mathematical function of levels of different inputs(e.g., numbers of people in different jobs, acquisitions of different types, physical resources). (4) Long term planning. Resource allocation problems are generally concerned with up to one and a half years ahead. The longer term certainly offers both greater freedom of action and greater uncertainty. Thus it is difficult to generalize about long term planning problems. In other fields, however, O. R. has made a significant contribution to long range planning and it is likely to have one to make in librarianship as well. (5) Public relations. It is generally accepted that actual and potential users are too ignorant both of the range of library services provided and of how to make use of them. How should services be brought to the attention of potential users? The answer seems to lie in obtaining empirical evidence by controlled experiments in which a group of libraries participated. (6) Acquisition policy. In comparing alternative policies for acquisition of materials one needs to know the implications of each service which depends on the stock. Second is the relative importance to be ascribed to each service for each class of user. By reducing the level of the first, formal models will allow the librarian to concentrate his attention upon the value judgements which will be necessary for the second. (7) Loan policy. The approach to choosing between loan policies is much the same as the previous approach. (8) Manpower planning. For large library systems one should consider constructing models which will permit the skills necessary in the future with predictions of the skills that will be available, so as to allow informed decisions. (9) Management information system for libraries. A great deal of data can be available in libraries as a by-product of all recording activities. It is particularly tempting when procedures are computerized to make summary statistics available as a management information system. The values of information to particular decisions that may have to be taken future is best assessed in terms of a model of the relevant problem. (10) Management gaming. One of the most common uses of a management game is as a means of developing staff's to take decisions. The value of such exercises depends upon the validity of the computerized model. If the model were sufficiently simple to take the form of a mathematical equation, decision-makers would probably able to learn adequately from a graph. More complex situations require simulation models. (11) Diagnostics tools. Libraries are sufficiently complex systems that it would be useful to have available simple means of telling whether performance could be regarded as satisfactory which, if it could not, would also provide pointers to what was wrong. (12) Data banks. It would appear to be worth considering establishing a bank for certain types of data. It certain items on questionnaires were to take a standard form, a greater pool of data would de available for various analysis. (13) Effectiveness measures. The meaning of a library performance measure is not readily interpreted. Each measure must itself be assessed in relation to the corresponding measures for earlier periods of time and a standard measure that may be a corresponding measure in another library, the 'norm', the 'best practice', or user expectations.

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A Study of Performance Analysis on Effective Multiple Buffering and Packetizing Method of Multimedia Data for User-Demand Oriented RTSP Based Transmissions Between the PoC Box and a Terminal (PoC Box 단말의 RTSP 운용을 위한 사용자 요구 중심의 효율적인 다중 수신 버퍼링 기법 및 패킷화 방법에 대한 성능 분석에 관한 연구)

  • Bang, Ji-Woong;Kim, Dae-Won
    • Journal of Korea Multimedia Society
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    • v.14 no.1
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    • pp.54-75
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    • 2011
  • PoC(Push-to-talk Over Cellular) is an integrated technology of group voice calls, video calls and internet based multimedia services. If a PoC user can not participate in the PoC session for various reasons such as an emergency situation, lack of battery capacity, then the user can use the PoC Box which has a similar functionality to the MM Box in the MMS(Multimedia Messaging Service). The RTSP(Real-Time Streaming Protocol) method is recommended to be used when there is a transmission session between the PoC box and a terminal. Since the existing VOD service uses a wired network, the packet size of RTSP-based VOD service is huge, however, the PoC service has wireless communication environments which have general characteristics to be used in RTSP method. Packet loss in a wired communication environments is relatively less than that in wireless communication environment, therefore, a buffering latency occurs in PoC service due to a play-out delay which means an asynchronous play of audio & video contents. Those problems make a user to be difficult to find the information they want when the media contents are played-out. In this paper, the following techniques and methods were proposed and their performance and superiority were verified through testing: cross-over dual reception buffering technique, advance partition multi-reception buffering technique, and on-demand multi-reception buffering technique, which are designed for effective picking up of information in media content being transmitted in short amount of time using RTSP when a user searches for media, as well as for reduction in playback delay; and same-priority packetization transmission method and priority-based packetization transmission method, which are media data packetization methods for transmission. From the simulation of functional evaluation, we could find that the proposed multiple receiving buffering and packetizing methods are superior, with respect to the media retrieval inclination, to the existing single receiving buffering method by 6-9 points from the viewpoint of effectiveness and excellence. Among them, especially, on-demand multiple receiving buffering technology with same-priority packetization transmission method is able to manage the media search inclination promptly to the requests of users by showing superiority of 3-24 points above compared to other combination methods. In addition, users could find the information they want much quickly since large amount of informations are received in a focused media retrieval period within a short time.

A study of Conjunctival Cellular Changes in Dry Eye Patients by Impression Cytology (Impression cytology를 이용한 건성안의 결막 세포변화에 관한 연구)

  • Kim, Jai-Min;Kho, Eun-Gyung;Chae, Soo-Chul;Kim, Soon-Ae
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.333-343
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    • 2004
  • Impression cytology refers to application of cellulose acetate filter material to the ocular surface to remove the superficial layers of the conjunctival epithelium. The technique is non-invasive, is easy to perform, causes minimal discomfort to the patient, and can be used to follow changes in the conjunctival ocular surface over time. With this method, the morphology of the conjunctival ocular surface can be studied and the degree of squmaous metaplasia assessed. This study was performed to evaluate the conjunctival surface by impression cytology in dry eye patients. A total of 70 students with no contact lens wearing history were recruited. Subjects were required to fill in a McMonnies dry eye symptom questionnaire. The non-invasive tear thinning time(TIT) test of each subject was measured, followed by Schirmer tear test(STI), tear film break-up time(TBUT) tests and Rose-bengal staining were performed as a baseline. Conjunctival epithelial cells from the inferior bulbar conjunctiva were harvested by the impression cytology technique. The specimens collected were labelled and stained with PAS(Periodic Acid Schift)-haematoxylin. The goblet cells and conjunctival epithelial cells were observed under a light microscope of 400x magnification. The specimens were classified according to the Nelson Grading scale which was based on the degree of squamous metaplasia such as changes of goblet cells density, size/form, N:C(nucleus : cytoplasm) ratio. Dry eye patients were observed morphological changes of the epithelial cells, different nuclear alterations, decrease of the goblet cells density. The degree of cytological changes was related to severity of dry eye conditions. When the epithelial cell morphology was graded according to the system described by Nelson, specimens from the control group revealed 91.43% of the eyes to be grade 0 and 8.57% to be grade 1, whereas of the dry eye patients, 20% were grade 0, 42.86% grade 1, 34.29% grade 2 and 2,86% grade 3. Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. This technique is a safe, simple method and may help increase understanding of various ocular surface alterations in dry eye patients.

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The Empirical Study on the Effects of the Team Empowerment caused by the Team-Based Organizational Structure in KBS (팀제가 팀 임파워먼트에 미치는 영향에 관한 연구;KBS 팀제를 중심으로)

  • Ahn, Dong-Su;Kim, Hong
    • 한국벤처창업학회:학술대회논문집
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    • 2006.04a
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    • pp.167-201
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    • 2006
  • Korean corporations are transforming their vertical operational structure to a team-based structure to compete in the rapidly changing environment and for improved performance. However, a high percentage of the respondents in KBS said that despite the appearance of the present team structure, the organization operates much like a vertically-structured organization. This result can be attributed to the lack of study and implementation toward the goal of empowerment, the key variable for the success of the team-based structure. This study aims to provide policy suggestions on how to implement the process of empowerment, by investigating the conditions that hinder the process and the attitude of the KBS employees. For the cross-sectional study, this thesis examined the domestic and international references, conducted a survey of KBS employees, personal interviews and made direct observations. Approximately 1,200 copies of the Questionnaire were distributed and 474 were completed and returned. The analysis used SPSS 12.0 software to process the data collected from 460 respondents. For the longitudinal-study, six categories that were common to this study and "The Report of the Findings of KBS Employees' View of the Team Structure" were selected. The comparative study analyzed the changes in a ten-month period. The survey findings showed a decrease of 24.2%p in the number of responses expressing negative views of the team structure and a decrease of 1.29%p in the number of positive responses. The findings indicated a positive transformation illustrating employees' improved understanding and approval of the team structure. However, KBS must address the issue on an ongoing basis. It has been proven that the employee empowerment increases the productivity of the individual and the group. In order to boost the level of empowerment, the management must exercise new, innovative leadership and build trust between the managers and the employees first. Additional workload as a result of shirking at work places was prevalent throughout all divisions and ranks, according to the survey data. This outcome leads to the conclusion that the workload is not evenly distributed or shared. And the data also showed the employees do not trust the assessment and rewards system. More attention and consideration must be paid to the team size and job allocation in order to address this matter; the present assessment and rewards system need to be complemented. The type of leadership varies depending on the characteristics of the organization's structure and employees' disposition. KBS must develop and reform its own management, leadership style to suit the characteristics of individual teams. Finally, for a soft-landing of KBS team structure, in-house training and education are necessary.

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