• Title/Summary/Keyword: 종단적 분석

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A Study on the Changes in the Domestic Start-up Environment and Start-up Perception: Focusing on the changes in 2016 and 2021 (국내 창업환경 및 창업인식 변화에 관한 연구: 2016년과 2021년 변화를 중심으로)

  • Nam, Jung-Min;Lee, Sung-Ho;Lee, So-Jung;You, Hyun-Kyung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.6
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    • pp.145-155
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    • 2021
  • This study aims to examine the results of start-up policies of the previous government (2013-2017) and the current government (2017-2022). We would like to compare the perceptions of founders on the domestic start-up environment in 2016 and 2021. Based on the data (GETR) that surveyed the perception of the startup environment in 2016, a trend survey was conducted to compare the perception of the start-up environment of founders in 2021. As a result of the study, the founder's perception of the domestic start-up environment changed positively overall, but there was no significant change in the perception of 'tax adequacy', 'easy to recover investment', and 'easy to transfer technology'. In addition, the perception of the start-up environment of livelihood founders was negative compared to opportunity-type start-ups. As such, different results were found for each type of start-up. This study analyzed the difference in perception of the past and present start-up environment from the perspective of founders. In particular, I would like to propose a plan to improve the quality of the domestic start-up environment by seeking support measures for livelihood-type start-ups that have collapsed due to COVID-19.

A Longitudinal Study for 3 Years on Myopic Refractive Error Changes of Myopic Children Among Patients of a Korean Optometry Clinic (국내 한 안경원을 방문한 근시 어린이의 3년간 근시도 변화의 추적 연구)

  • Kim, Jin-Suk;Kim, Jae-Do
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.3
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    • pp.249-254
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    • 2012
  • Purpose: To investigate amount of myopic progression with increase of age for children myopes among patients of a Korean optometry clinic. Methods: It has followed up 99 children subjects (male 55, female 44) who had no ocular disease and have visited a Korean optometric clinic for mean $33{\pm}8$ months (13 to 54 months) since June of 2001. Mean age of subjects at first visit was $118{\pm}23$months. Non-cycloplegic refractive error were measured 6 times using Canon RK-3(Japan) every mean 6 months. Results: For all subjects mean of refractive errors increased -0.78 D per year from $-2.02{\pm}1.05D$ at first visit to $-4.18{\pm}1.30D$ at final visit with longitudinal study, but -0.19 D per year with cross-section study, which showed a big difference between two methods. Mean of astigmatic refractive error increased -0.15 D per year. As progression of refractive error according to ages at first visit, refractive errors increased -1.04 D per year for 6 years old, -0.9 D for 7 years old, -0.89 D for 8 years old, -0.89 D for 9 years old, -0.74 D for 10 years old, -0.74 D for 11 years old and -0.72 D for 12 years old. And it showed a tendency that the younger age was the higher progression of myopia. However it was not significantly different between each groups. Conclusions: Follow-up results for myopic children among patients of a Korean optometry clinic showed increase of -0.78 D for myopic refractive error and -0.14 D for astigmatic refractive error per year.

A Data-based Sales Forecasting Support System for New Businesses (데이터기반의 신규 사업 매출추정방법 연구: 지능형 사업평가 시스템을 중심으로)

  • Jun, Seung-Pyo;Sung, Tae-Eung;Choi, San
    • Journal of Intelligence and Information Systems
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    • v.23 no.1
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    • pp.1-22
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    • 2017
  • Analysis of future business or investment opportunities, such as business feasibility analysis and company or technology valuation, necessitate objective estimation on the relevant market and expected sales. While there are various ways to classify the estimation methods of these new sales or market size, they can be broadly divided into top-down and bottom-up approaches by benchmark references. Both methods, however, require a lot of resources and time. Therefore, we propose a data-based intelligent demand forecasting system to support evaluation of new business. This study focuses on analogical forecasting, one of the traditional quantitative forecasting methods, to develop sales forecasting intelligence systems for new businesses. Instead of simply estimating sales for a few years, we hereby propose a method of estimating the sales of new businesses by using the initial sales and the sales growth rate of similar companies. To demonstrate the appropriateness of this method, it is examined whether the sales performance of recently established companies in the same industry category in Korea can be utilized as a reference variable for the analogical forecasting. In this study, we examined whether the phenomenon of "mean reversion" was observed in the sales of start-up companies in order to identify errors in estimating sales of new businesses based on industry sales growth rate and whether the differences in business environment resulting from the different timing of business launch affects growth rate. We also conducted analyses of variance (ANOVA) and latent growth model (LGM) to identify differences in sales growth rates by industry category. Based on the results, we proposed industry-specific range and linear forecasting models. This study analyzed the sales of only 150,000 start-up companies in Korea in the last 10 years, and identified that the average growth rate of start-ups in Korea is higher than the industry average in the first few years, but it shortly shows the phenomenon of mean-reversion. In addition, although the start-up founding juncture affects the sales growth rate, it is not high significantly and the sales growth rate can be different according to the industry classification. Utilizing both this phenomenon and the performance of start-up companies in relevant industries, we have proposed two models of new business sales based on the sales growth rate. The method proposed in this study makes it possible to objectively and quickly estimate the sales of new business by industry, and it is expected to provide reference information to judge whether sales estimated by other methods (top-down/bottom-up approach) pass the bounds from ordinary cases in relevant industry. In particular, the results of this study can be practically used as useful reference information for business feasibility analysis or technical valuation for entering new business. When using the existing top-down method, it can be used to set the range of market size or market share. As well, when using the bottom-up method, the estimation period may be set in accordance of the mean reverting period information for the growth rate. The two models proposed in this study will enable rapid and objective sales estimation of new businesses, and are expected to improve the efficiency of business feasibility analysis and technology valuation process by developing intelligent information system. In academic perspectives, it is a very important discovery that the phenomenon of 'mean reversion' is found among start-up companies out of general small-and-medium enterprises (SMEs) as well as stable companies such as listed companies. In particular, there exists the significance of this study in that over the large-scale data the mean reverting phenomenon of the start-up firms' sales growth rate is different from that of the listed companies, and that there is a difference in each industry. If a linear model, which is useful for estimating the sales of a specific company, is highly likely to be utilized in practical aspects, it can be explained that the range model, which can be used for the estimation method of the sales of the unspecified firms, is highly likely to be used in political aspects. It implies that when analyzing the business activities and performance of a specific industry group or enterprise group there is political usability in that the range model enables to provide references and compare them by data based start-up sales forecasting system.

Case Study on the Enterprise Microblog Usage: Focusing on Knowledge Management Strategy (기업용 마이크로블로그의 사용행태에 대한 사례연구: 지식경영전략을 중심으로)

  • Kang, Min Su;Park, Arum;Lee, Kyoung-Jun
    • Journal of Intelligence and Information Systems
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    • v.21 no.1
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    • pp.47-63
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    • 2015
  • As knowledge is paid attention as a new production factor that generates added value, studies continue to apply knowledge management to business environment. In addition, as ICT (Information Communication Technology) was engrafted in business environment, it leads to increasing task efficiency and productivity of individual workers. Accordingly, the way that a business achieves its goal has changed to one in which its individual members are willing to take part in the organization and share information to create new values (Han, 2003) and studies for the system and service to support such transition are carrying out. Of late, a new concept called 'Enterprise 2.0' newly appears. It is the extension of Wen 2.0 and its technology, which focus on participation, sharing and openness, to the work environment of a business (Jung, 2013). Enterprise 2.0 is being used as a collaborative tool to prop up individual creativity and group brain power by combining Web 2.0 technologies such as blog, Wiki, RSS and tag with business software (McAfee, 2006). As Tweeter gets popular, Enterprise Microblog (EMB), which is an example of Enterprise 2.0 for business, has been developed as equivalent to Tweeter in business circle and SaaS (Software as a Service) such as Yammer was introduced The studies of EMB mainly focus on demonstrating its usability in terms of intra-firm communication and knowledge management. However existing studies lean too much towards large-sized companies and certain departments, rather than a company as a whole. Therefore, few studies have been conducted on small and medium-sized companies that have difficulty preparing separate resources and supplying exclusive workforce to introduce knowledge management. In this respect, the present study placed its analytic focus on small-sized companies actually equipped with EMB to know how they use it. And, based on the findings, this study examined their knowledge management strategies for EMB from the point of codification and personalization. Hypothesis -"as a company grows, it shifts EMB strategy from codification to personalization'- was established on the basis of reviewing precedent studies and literature. To demonstrate the hypothesis, this study analyzed the usage of EMB by small companies that have used it from foundation. For case study, the duration of the use was divided into 2 spans and longitudinal analysis was employed to examine the contents of the blogs. Using the key findings of the analysis, this study is aimed to propose practical implications for the operation of knowledge management of small-sized company and the suitable application of knowledge management system for operation Knowledge Management Strategy can be classified by codification strategy and personalization strategy (Hansen et. al., 1999), and how to manage the two strategies were always studied. Also, current studies regarding the knowledge management strategy were targeted mostly for major companies, resulting in lack of studies in how it can be applied on SMEs. This research, with the knowledge management strategy suited for SMEs, sets an Enterprise Microblog (EMB), and with the EMB applied on SMEs' Knowledge Management Strategy, it is reviewed on the perspective of SMEs' Codification and Personalization Strategies. Through the advanced research regarding Knowledge Management Strategy and EMB, the hypothesis is set that "Depending on the development of the company, the main application of EMB alters from Codification Strategy to Personalization Strategy". To check the hypothesis, SME that have used the EMB called 'Yammer' was analyzed from the date of their foundation until today. The case study has implemented longitudinal analysis which divides the period when the EMBs were used into three stages and analyzes the contents. As the result of the study, this suggests a substantial implication regarding the application of Knowledge Management Strategy and its Knowledge Management System that is suitable for SME.

A Study on Framework to offer the differentiated Optical QoS Service in the Next-Generation WDM Optical Internet Backbone Network (차세대 WDM 광 인터넷 백본망에서 차등화된 광 QoS 서비스 제공 프레임워크 연구)

  • Kim Yong-Seoug;Ryu Shi-Kook;Lee Jae-Dong;Kim Sung-Un
    • The KIPS Transactions:PartC
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    • v.12C no.6 s.102
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    • pp.881-890
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    • 2005
  • Over for the past 10 years, the increase in geometric progression for the internet traffic, has allowed the IP protocol framework to be the most important network technology. In addition, the internet service is being developed as a service mode differentiated, aiming to support the new-mode real-time multimedia services such as internet phone, video conference, cyber reality, and internet game, focusing on offering a latest service. These days, aiming to solve the need for broad bandwidth along with guaranteeing QoS, the WDM technology of offering multiple gigabit wavelengths is emerging as the core technology of next-generation optical internet backbone network. In the next-generation optical internet backbone network based on WDM, the QoS framework is one of fore subjects aiming to offer a service of guaranteeing QoS This study analyzes the requirements of performance related to QoS framework in IP Subnet and in WDM optical backbone network, and suggests optical QoS service framework differentiated. in order to guarantee end-to-end QoS through the next-generation optical internet backbone network, using GMPLS control protocol.

Study on the Maintenance Cost of Railway Infrastructure Using Line Classification and TMV Data (선로등급 및 검측차 검측정보를 고려한 철도시설 유지보수비용 산정에 관한 연구)

  • Kim, In Kyum;Lee, Jun S.;Choi, Il Yoon;Lee, Hoo Seok
    • Journal of the Korean Society for Railway
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    • v.20 no.2
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    • pp.275-287
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    • 2017
  • During the feasibility study of new rail lines, maintenance cost of railway infrastructure has mostly been estimated based on the track length and on simplified parameters; however, the estimation reliability can be improved by employing the correction factor from UIC 715, as well as the line classification in UIC 714. The correlations between maintenance cost and various parameters such as weighted track length based on line classification, radius of curvature, gradient and worn -out rate have been analyzed according to the case studies. Prediction of the maintenance cost has been carried out using the cost data, which were representative of the whole cost data; as a result, it was demonstrated that a cost model based on the line classification and the correction factor was more reliable than the existing models. Furthermore, possibilities of using data from both the track measurement vehicle and from the maintenance information system, which are under development, have been investigated and, based on this investigation, a combined cost model using line classification, radius of curvature, gradient and worn-out rate, among other factors, will be proposed in the near future.

Effect of threats to anonymity on data reliability in internet survey (인터넷 설문조사에서 익명성 훼손이 응답에 미치는 효과)

  • Heo, Sun-Yeong;Chang, Duk-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.4
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    • pp.785-794
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    • 2011
  • The population of internet users are rapidly increasing and the interest of the internet survey is also increasing. Recent years has seen a transition from traditional modes of data collection into internet survey. Some surveys are administered with mixed modes of traditional data collection methods and internet survey, and some surveys are conducted through internet only instead of traditional modes, such as telephone survey, postal survey, face-to-face interviews and so on. However, one of most crucial parts of a survey is the reliability of the collected data and internet survey is no exemption. Changwon National University has been annually conducting a survey of new students and transfer students with almost same contents of questionnaire. The survey is a longitudinal survey and it had been administered by paper-pencil surveys until 2009. In 2010 the survey was administered through internet. Every students has to login with student ID number and the last 7-digit of national identity registration number, and complete the 2010 survey before registration their courses. If they leave any question without being answered, then could not move to the registration site for courses. This study explores the distortion of responses using the new students survey of Changwon National University, which could occur when the survey responses are not confidential. We find that the distortion of responses occurs from the questions with social desirability pressure, pressure of winning favor with the researcher, and pressure of explaining their situations. There are no distortion of responses from the questions which are describing simple opinions or simple facts, for example, the place they plan to live while in school.

Synoptic Climatological Characteristics of Autumn Droughts in Korea (한국의 추계한발의 종관기후학적 특성)

  • Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
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    • v.6 no.2
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    • pp.57-69
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    • 2000
  • The purpose of this study is to identify distributional characteristics of autumn droughts in occurrence frequency and to analyze synoptic characteristics on the surface pressure fields and 500hPa levels for autumn droughts in Korea. The regional distributions of autumn droughts in occurrence frequency vary according to the monthly regional distributions of the precipitation variabilities in Korea. In september, the southwestern and the mid western parts of Korean Peninsula have high rate of drought frequency, while the eastern coast regions have low rate of it. It means that the regional distribution of the drought frequency in september indicates west-high and east-low pattern. In October, the regional distribution of the drought frequency shows low variations on regions, but in November the inland areas have low rate of drought frequency, whereas the coastal areas have high rate of it. Negative anomalies appear on the surface and 500hPa level, around Korean Peninsula during the drought period of early autumn. Positive height anomalies areas are extended from the Sea of Okhotsk to the central part of the North Pacific Ocean. It indicates that the occurrence frequencies of blocking high and ridge are high around the Sea of Okhotsk. When the pressure system, such as migratory anticyclone, stays around the Korean Peninsula, a drought occurs. In late autumn drought, the positive anomalies appear in the west and the negative anomalies in the east are generated, respectively and therefore, zonal wind is strong around Korean Peninsula. In consequence, occurrences of droughts in early autumn have a different mechanism from those of late autumn.

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Study on the Coefficient of Thermal Expansion for Composites Containing 2-Dimensional Ellipsoidal Inclusions (2차원 타원형의 충전제를 함유하는 복합재료의 열팽창 계수 연구)

  • Lee, Kee-Yoon;Kim, Kyung-Hwan;Jeoung, Sun-Kyoung;Jeon, Hyoung-Jin;Joo, Sang-Il
    • Polymer(Korea)
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    • v.31 no.2
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    • pp.160-167
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    • 2007
  • This paper proposes a model for the solutions predicting the coefficient of thermal expansion of composites including fiber-like shaped$(a_1>a_2=a_3)$ and disk-like shaped$(a_1=a_2>a_3)$ inclusions like two dimensional geometries, which was analyzed by one axis and a single aspect ratio, $(\rho_\alpha=a_1/a_3)$. The analysis follows the procedure developed for elastic moduli by using the Lee and Paul's approach. The effects of the aspect ratio on the coefficient of thermal expansion of composites containing aligned isotropic inclusions are examined. This model should be limited to analyze the composites with unidirectionally aligned inclusions and with complete binding to each other of both matrix and inclusions having homogeneous properties. The longitudinal coefficients of thermal expansion $\alpha_{11}$ decrease and approach the coefficient of thermal expansion of filler, as the aspect ratios increase. However, the transverse coefficients of thermal expansion $\alpha_{33}$ increase or decrease with the aspect ratios.

Experimental Study on the Ground Behavior around a Tunnel due to the Sidewall Deformation of Shallow Tunnel in Longitudinal Direction Excavated under the Slope (사면 하부지반에 종단 방향으로 굴착한 얕은 터널에서 측벽변형에 따른 터널 주변지반의 거동에 대한 실험적 연구)

  • Na, Yong Soo;Lee, Sang Duk
    • Journal of the Korean Geotechnical Society
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    • v.35 no.5
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    • pp.21-30
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    • 2019
  • While the study of the shallow tunnel has been mainly on the longitudinal load transfer and horizontal surface conditions, the study of the ground behavior of shallow tunnel under the slope is not sufficient. Therefore, in this study on the ground behavior around a tunnel due to the sidewall deformation of shallow tunnel under the slope that is excavated in longitudinal direction, a scale-down model test has been performed. The model tunnel has the dimension of 320 mm wide, 210 mm high and 55 mm long with enough material strength in aluminum and the model ground has the uniform ground conditions by 3 types of carbon rods. The model test has been performed with the variables of slopes and the cover depths by controlling the tunnel sidewall deformation, and the change of sidewall-load, load transfer, ground subsidence was monitored and analyzed. According to the increase of the slope, the maximum ground subsidence increased by 20~39% compared to the horizontal surface. The load ratio increased by maximum 20% in the tunnel crown and decreased in sidewall according to the surface slope. The load transfer shows maximum 128% of increase at the cover depth of 1.0D, while at the 1.5D cover depth it shows non-critical difference from horizontal surface. The slope has major effects on load transfer at the cover depth of 1.0D.