• Title/Summary/Keyword: retaining time

Search Result 273, Processing Time 0.039 seconds

Evaluating the Multi-Period Management Efficiency of Domestic Online-Shopping Companies (DEA와 Malmquist 생산성지수를 이용한 우리나라 온라인쇼핑업체의 다기간 경영 효율성 분석)

  • Ma, Jin-Hee;Ja, Yoon-Ho;Ahn, Young-Hyo
    • Journal of Distribution Science
    • /
    • v.13 no.4
    • /
    • pp.45-53
    • /
    • 2015
  • Purpose - Online shopping enables consumers to conveniently purchase products irrespective of the time and place. As a result, several online shopping companies have emerged to cater to this growing market and, therefore, the competition among them has become increasingly intense. This paper evaluates the comparative efficiency of online shopping companies for a multi-year period (2009-2013), in order to help online shopping managers identify major drivers for enhancing management efficiency and the subsequent competitiveness. Research design, data, and methodology - The researchers collected the data from 2009 to 2013 from the distribution yearbook. This paper analyzes the marketability (sales figures), profitability (business profits), and management conditions (net profits) of domestic online shopping enterprises by incorporating information on human resources (number of employees) and material resources (total assets and capital). Therefore, the number of employees, total assets, and capital are selected as input variables, and sales figures, business profits, and net profits as the output variables. In this study, Data Envelopment Analysis (DEA) was used to measure the comparative efficiency of domestic online shopping companies. In addition, the Malmquist Productivity Index was used to evaluate the trend of change of Decision Making Units' (DMUs') efficiency for a multi-year period. Results - First, as of 2013, Interpark (2.415) was found to be the most efficient online shopping enterprise, followed by Aladdin Communications (2.117), Hyundai Home shopping (1.867), Home&Shopping (1.176), NS Home shopping (1.170), Commerce Planet (1.126), CJ O Shopping (1.105), Ebay Korea (1.088), and GS Home Shopping (1.051). Second, this study recognizes how the management efficiency has changed for the period 2009-2013. Third, the lesser the capital and employees, the more are the net profits, and the better is the management efficiency of domestic online shopping companies. Lastly, the productivity of such companies is influenced by endogenous factors rather than exogenous factors such as shifts in business environment and technological advances. Conclusions - DHC Korea influenced various distribution channels to reach customers through the Internet. Consequently, this helped in increasing the awareness about its products, in addition to an increase in sales. These achievements can be attributed to the characteristics of online shopping companies. Although it is easy for these companies to suggest goods for one-off purchases, they however have difficulties in retaining customers. Overcoming this challenge can be one of the ways to benchmark a successful case of an efficient company. For example, an online shopping company can attract customers by developing a corresponding mobile application as a convenient way to shop online. Additionally, they can satisfy customers by quick delivery of purchased products, which is possible by building an effective logistics network. Our study indicates that the productivity of an online shopping company was influenced by endogenous factors driven by improvements in managerial practices rather than exogenous factors. Accordingly, online shopping companies should adopt strategies to improve their operational efficiency rather than sales volume-oriented management.

High-Level Expression of T4 Endonuclease V in Insect Cells as Biologically Active Form

  • Kang, Chang-Soo;Son, Seung-Yeol;Bang, In-Seok
    • Journal of Microbiology and Biotechnology
    • /
    • v.16 no.10
    • /
    • pp.1583-1590
    • /
    • 2006
  • T4 endonuclease V (T4 endo V) [EC 3. 1. 25. 1], found in bacteriophage T4, is responsible for excision repair of damaged DNA. The enzyme possesses two activities: a cyclobutane pyrimidine dimer DNA glycosylase (CPD glycosylase) and an apyrimidic/apurinic endonuclease (AP lyase). T4 denV (414 bp cDNA) encoding T4 en do V (138 amino acid) was synthesized and expressed using either an expression vector, pTriEx-4, in E. coli or a baculovirus AcNPV vector, pBacPAK8, in insect cells. The recombinant His-Tag/T4 endo V (rHis-Tag/T4 endo V) protein expressed from bacteria was purified using one-step affinity chromatography with a HiTrap Chelating HP column and used to make rabbit anti-His-Tag/T4 endo V polyclonal antibody for detection of recombinant T4 endo V (rT4 endo V) expressed in insect cells. In the meantime, the recombinant baculovirus was obtained by cotransfection of BacPAK6 viral DNA and pBP/T4 endo V in Spodoptera frugiperda (Sf21) insect cells, and used to infect Sf21 cells to overexpress T4 endo V protein. The level of rT4 endo V protein expressed in Sf21 cells was optimized by varying the virus titers and time course of infection. The optimal expression condition was set as follows; infection of the cells at a MOI of 10 and harvest at 96 h post-infection. Under these conditions, we estimated the amount of rT4 endo V produced in the baculovirus expression vector system to be 125 mg/l. The rT4 endo V was purified to homogeneity by a rapid procedure, consisting of ion-exchange, affinity, and reversed phase chromatographies, based on FPLC. The rT4 endo V positively reacted to an antiserum made against rHis-Tag/T4 endo V and showed a residual nicking activity against CPD-containing DNA caused by UV. This is the first report to have T4 endo V expressed in an insect system to exclude the toxic effect of a bacterial expression system, retaining enzymatic activity.

Numerical analysis on stability of express railway tunnel portal

  • Zhou, Xiaojun;Hu, Hongyun;Jiang, Bo;Zhou, Yuefeng;Zhu, Yong
    • Structural Engineering and Mechanics
    • /
    • v.57 no.1
    • /
    • pp.1-20
    • /
    • 2016
  • On the basis of the geological conditions of high and steep mountainous slope on which an exit portal of an express railway tunnel with a bridge-tunnel combination is to be built, the composite structure of the exit portal with a bridge abutment of the bridge-tunnel combination is presented and the stability of the slope on which the express railway portal is to be built is analyzed using three dimensional (3D) numerical simulation in the paper. Comparison of the practicability for the reinforcement of slope with in-situ bored piles and diaphragm walls are performed so as to enhance the stability of the high and steep slope. The safety factor of the slope due to rockmass excavation both inside the exit portal and beneath the bridge abutment of the bridge-tunnel combination has been also derived using strength reduction technique. The obtained results show that post tunnel portal is a preferred structure to fit high and steep slope, and the surrounding rock around the exit portal of the tunnel on the high and steep mountainous slope remains stable when rockmass is excavated both from the inside of the exit portal and underneath the bridge abutment after the slope is reinforced with both bored piles and diaphragm walls. The stability of the high and steep slope is principally dominated by the shear stress state of the rockmass at the toe of the slope; the procedure of excavating rockmass in the foundation pit of the bridge abutment does not obviously affect the slope stability. In-situ bored piles are more effective in controlling the deformation of the abutment foundation pit in comparison with diaphragm walls and are used as a preferred retaining structure to uphold the stability of slope in respect of the lesser time, easier procedure and lower cost in the construction of the exit portal with bridge-tunnel combination on the high and steep mountainous slope. The results obtained from the numerical analysis in the paper can be used to guide the structural design and construction of express railway tunnel portal with bridge-tunnel combination on high and abrupt mountainous slope under similar situations.

A Study on the Regional Labor Market Experiences of Young Women in Jeollanam-do Province: Focusing on the Labor Mobility (전남지역 대졸 청년여성의 지역노동시장 경험연구: 노동이동을 중심으로)

  • Jun, Myung-Sook
    • Korean Journal of Labor Studies
    • /
    • v.24 no.2
    • /
    • pp.215-245
    • /
    • 2018
  • The purpose of this study is to provide policy implications on the settlement of regional labor market of young women through detailed study on the experience of regional labor market in Jeollanam-do Province. For this purpose, this study analyzed the labor mobility experience in the regional labor market of young women, which lacked specific case studies. In this study, we have identified the causes of job changes by dividing the labor mobility of young women into intra-career moves and inter-career moves. For the causes of labor mobility we divided into two aspects: problems in preparation for employment and employment conditions. The inter-career moves included more diverse factors than intra-career moves. In the inter-career moves, problems in preparation for employment were highlighted as the causes of job changes. In the case of moving within the career, young women would leave because of the employment conditions such as the expiration of the employment period, but the turnover appears to be the way of retaining their previous career. On the other hand, in the case of intra-career moves, the strong desire to maintain the career was shown, and at the same time, the possibility of leaving the region was also high. Based on the case study, this study proposed systematic career counseling for career match, and construction of career management system to support continuous career development.

Analysis of Slope Stability of Masonry Retaining Walls in Quarry (석산개발 지역 퇴적장 석축사면의 안정성 해석)

  • Ma, Ho-Seop;Lee, Sung-Jae
    • Journal of Korean Society of Forest Science
    • /
    • v.107 no.4
    • /
    • pp.385-392
    • /
    • 2018
  • The slope stabilization analysis was performed by conducting survey and selecting the representative section in order to improve slope composition and management technology of masonry embankments in the quarry area, The mean slope of the masonry retain wall (A, B, C, D, E, F) was $38.5^{\circ}$, although the steep slope of the lowest slope (A) as $59^{\circ}$. The horizontal distance of the masonry embankments is 66.2 m and the slope height is 48.3 m. However, the inclination of the masonry embankments is relatively steep and visually unstable. The slope stability analysis for the slope stability analysis was taken into account during the drying and saturation. The slope stability analysis during saturation was performed by modeling the fully saturated slope. The strength constants of the ground were divided into two groups. The safety factor for dry period was 1.850 and the safety factor for rainy season was 1.333. The safety rate of dry period and rainy season was above 1.5 and 1.2. However, the weathered granite on the upper part of the masonry embankments at the time of heavy rainfall is considered to have a high risk of slope erosion and collapse. Therefore, it is considered necessary to take measures for stabilization through appropriate maintenance such as drainage installation.

A Study on Earth Pressure Properties of Granulated Blast Furnace Slag Used as Back-fill Material (뒷채움재로 이용한 고로 수쇄슬래그의 토압특성에 관한 실험적 연구)

  • Baek, Won-Jin;Lee, Kang-Il
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.8
    • /
    • pp.119-127
    • /
    • 2006
  • Granulated Blast Furnace Slag (GBFS) is produced in the manufacture process of pig-iron and shows a similar particle formation to that of natural sea sand and also shows light weight, high shear strength, well permeability, and especially has a latent hydraulic property by which GBFS is solidified with time. Therefore, when GBFS is used as a backfill material of quay or retaining walls, the increase of shear strength induced by the hardening is presumed to reduce the earth pressure and consequently the construction cost of harbor structures decreases. In this study, using the model sand box (50 cm$\times$50 cm$\times$100 cm), the model wall tests were carried out on GBFS and Toyoura standard sand, in which the resultant earth pressure, a wall friction and the earth pressure distribution at the movable wall surface were measured. In the tests, the relative density was set as Dr=25, 55 and 70% and the wall was rotated at the bottom to the active earth pressure side and followed by the passive side. The maximum horizontal displacement at the top of the wall was set as ${\pm}2mm$. By these model test results, it is clarified that the resultant earth pressure obtained by using GBFS is smaller than that of Toyoura sand, especially in the active-earth pressure.

Changes in Protease and Formonitrogen of Salted Fish and Shellfish (1) (젓갈 성숙과정(成熟過程)에 있어 Protease 및 Formonitrogen의 변화(變化)에 관(關)한 연구(硏究)(1))

  • Suh, Myung-Jah
    • Journal of Nutrition and Health
    • /
    • v.6 no.2
    • /
    • pp.45-56
    • /
    • 1973
  • Salted fish and shellfish have been widely used in Korea from olden times as side-dishes, although the processes and methods of pickling have varied depending on localities. The common raw materials for these subsidiary food articles include anchovy, shrimp, yellow corvina, oysters, octopus, top-shell, shellfish, pollack roe and pollack intestines. It must be pointed out here, however, that the salted stuffs now marketed locally are highly unscientific and unsanitary in the way they are processed and sold, and this has prompted this writer to undertake a study on these native food articles. The following findings have been obtained from this study on the changes in Formonitrogen and Protease Activity, effected by the density of salt and the degree of storing temperature, of the pickles of cedfish gills, codfish intestines, pollack intestines, shellfish, oysters, cuttle fish and octopus. 1) Codfish Gills The Protease Activity of the pickled codfish gills was greater in the groups of lesser doses of salt and higher degrees of storing temperature. The same was true in the case of Formonifrogen, too. The Formonitrogen of the pickled codfish gills was larger in the groups of lesser salt and higher teimperature. 2) Codfish Intestines The amount of Formonitrogen of the pickled codfiah intestines became greater, as time went by, in the groups of lesser salt than those of larger doses of salt, with the speed of its formation getting faster as the storing temperature rose from $5^{\circ}C$ to $15^{\circ}C$ and $30^{\circ}C$. The Protease Activity was also greater in the groups of lesser salt and higher temperature. The group, stored at 10% salt and $30^{\circ}C$, rotted in five days. 3) Pollack Intestines The amount of Formonitrogen of the pickled pollack intestines was greater in the groups of lesser amount of salt and higher degrees of storing temperature. The Protease Activity of the pickled pollack intestines began decreasing from the 11th day after the pickling in the groups stored at colmparatively high degrees of temperature$(15^{\circ}C-30^{\circ}C)$, while that of the group stored at $5^{\circ}C$ kept rising. The effects of the amount of salt were little. The group stored at 15% salt and $30^{\circ}C$ started rotting on the 13th day while that stored at $30^{\circ}C$ decayed on the 7th day. The group stored at 20% salt and $30^{\circ}C$ rotted on the 9th day. 4) Oysters The amount of Formonitrogen of the pickled oysters became greater as the storing temperature rose and the doses of salt were lowered. The Protease Activity was not affected at any measurable degree by the density of salt in the group stored at $5^{\circ}C$, but became greater as the storing temperature rose to $15^{\circ}C$ and $30^{\circ}C$. The group stored at 10% salt and $30^{\circ}C$ rotted on the 5th day while that stored at 20% salt and $30^{\circ}C$ on the 13th day. 5) Shellfish The amount of Formonitrogen of the pickled shellfish became greater, as time went by, it the groups of lower consistency of salt than the groups of higher density of salt, although the decay of the former groups was faster than the latter groups. The density of salt best fitted for the pickling appeared to be about 20% with the storing temperature to be $15^{\circ}C$, at which the pickled stuff became most tasty on the 7th day. The oysters stored in three groups at $5^{\circ}C$, $15^{\circ}C$ and $30^{\circ}C$ respectively showed the greatest Protease Activity alike at 0% of salt, but the activity declined as the density of salt increased. The Protease Activity of each group rose for the first 11 days after the pickling, but began declining from the 13th day onward, with the groups of higher temperature retaining higher Protease Activity than the groups of lower temperature. 6) Cuttlefish Both the amount of Formonitrogen and the degree of Protease Activity of the pickled cuttlefish were greater in the groups of lower density of salt and higher degree of storing temperature. The oysters pickled at 10% salt and $15^{\circ}C$ degenerated on the 13th day while that of 10% salt and $30^{\circ}C$ deteriorated on the 7th day. 7) Octopus Both the Formonitrogen and the Protease Activity of the pickled octopus were greater in the groups of lower density of salt, but as time went by, the Protease Activity in all groups dwindled after a climbing. In general, the Formonitrogen and the Protease Activity of the pickled oysters became greater as the storing temperature got higher. One group stored at 10% salt and $15^{\circ}C$ rotted in 13days while another group stored at $30^{\circ}C$ decayed in 7 days.

  • PDF

Quality characteristics and preparing of solid starter using fungal strains for Takju (탁주용 곰팡이 고체종국 제조 및 품질 특성)

  • Baek, Chang-Ho;Baek, Seong Yeol;Mun, Ji-Young;Choi, Han-Seok;Kang, Ji-Eun;Jung, Seok-Tae;Yeo, Soo-Hwan
    • Food Science and Preservation
    • /
    • v.23 no.6
    • /
    • pp.797-803
    • /
    • 2016
  • In this study, we investigated the effect of fermentation conditions on the amylolytic and proteolytic activities of Aspergillus luchuensis strain 74-5 and Aspergillus oryzae strain 75-2, which are used in the preparation of the starter culture, for Takju (Korean traditional rice wine). The starter culture was optimized using different conditions, such as inoculum size, inoculation temperature, and incubation time. The enzyme activities under each condition were measured. In the A. luchuensis strain 74-5 starter culture, the ${\alpha}-amylase$ and glucoamylase activities increased, however the activity of acidic protease decreased as the diluent to starter culture ratio increased. In the A. oryzae 75-2 starter culture, all enzyme activities were maintained at a higher level even at 5% inoculation ratio. Higher enzyme activities were observed in the middle range of inoculation temperature (35, $40^{\circ}C$), than in the lower range (20, $30^{\circ}C$). Enzyme activity in the starter culture varied with incubation time, however it was the highest at 144 and 120 hr, respectively, for A. luchuensis strain 74-5 and A. oryzae strain 75-2. The spore count of the starter culture was approximately $2{\times}10^7$ during fermentation, out of which contamination by aerobic bacteria was about $3{\times}10^3$. The results suggested that the starter culture of each strain could be used as an inoculum for fermentation. However, we needs to conduct further research for the selection of suitable diluting agents as well as drying methods to reduce the contamination by aerobic bacteria, while retaining the enzyme activity.

Designing Mobile Framework for Intelligent Personalized Marketing Service in Interactive Exhibition Space (인터랙티브 전시 환경에서 개인화 마케팅 서비스를 위한 모바일 프레임워크 설계)

  • Bae, Jong-Hwan;Sho, Su-Hwan;Choi, Lee-Kwon
    • Journal of Intelligence and Information Systems
    • /
    • v.18 no.1
    • /
    • pp.59-69
    • /
    • 2012
  • As exhibition industry, which is a part of 17 new growth engines of the government, is related to other industries such as tourism, transportation and financial industries. So it has a significant ripple effect on other industries. Exhibition is a knowledge-intensive, eco-friendly and high value-added Industry. Over 13,000 exhibitions are held every year around the world which contributes to getting foreign currency. Exhibition industry is closely related with culture and tourism and could be utilized as local and national development strategies and improve national brand image as well. Many countries try various efforts to invigorate exhibition industry by arranging related laws and support system. In Korea, more than 200 exhibitions are being held every year, but only 2~3 exhibitions are hosted with over 400 exhibitors and except these exhibitions most exhibitions have few foreign exhibitors. The main reason of weakness of domestic trade show is that there are no agencies managing exhibitionrelated statistics and there is no specific and reliable evaluation. This might cause impossibility of providing buyer or seller with reliable data, poor growth of exhibitions in terms of quality and thus service quality of trade shows cannot be improved. Hosting a lot of visitors (Public/Buyer/Exhibitor) is very crucial to the development of domestic exhibition industry. In order to attract many visitors, service quality of exhibition and visitor's satisfaction should be enhanced. For this purpose, a variety of real-time customized services through digital media and the services for creating new customers and retaining existing customers should be provided. In addition, by providing visitors with personalized information services they could manage their time and space efficiently avoiding the complexity of exhibition space. Exhibition industry can have competitiveness and industrial foundation through building up exhibition-related statistics, creating new information and enhancing research ability. Therefore, this paper deals with customized service with visitor's smart-phone at the exhibition space and designing mobile framework which enables exhibition devices to interact with other devices. Mobile server framework is composed of three different systems; multi-server interaction, server, client, display device. By making knowledge pool of exhibition environment, the accumulated data for each visitor can be provided as personalized service. In addition, based on the reaction of visitors each of all information is utilized as customized information and so the cyclic chain structure is designed. Multiple interaction server is designed to have functions of event handling, interaction process between exhibition device and visitor's smart-phone and data management. Client is an application processed by visitor's smart-phone and could be driven on a variety of platforms. Client functions as interface representing customized service for individual visitors and event input and output for simultaneous participation. Exhibition device consists of display system to show visitors contents and information, interaction input-output system to receive event from visitors and input toward action and finally the control system to connect above two systems. The proposed mobile framework in this paper provides individual visitors with customized and active services using their information profile and advanced Knowledge. In addition, user participation service is suggested as well by using interaction connection system between server, client, and exhibition devices. Suggested mobile framework is a technology which could be applied to culture industry such as performance, show and exhibition. Thus, this builds up the foundation to improve visitor's participation in exhibition and bring about development of exhibition industry by raising visitor's interest.

A Meta Analysis of Using Structural Equation Model on the Korean MIS Research (국내 MIS 연구에서 구조방정식모형 활용에 관한 메타분석)

  • Kim, Jong-Ki;Jeon, Jin-Hwan
    • Asia pacific journal of information systems
    • /
    • v.19 no.4
    • /
    • pp.47-75
    • /
    • 2009
  • Recently, researches on Management Information Systems (MIS) have laid out theoretical foundation and academic paradigms by introducing diverse theories, themes, and methodologies. Especially, academic paradigms of MIS encourage a user-friendly approach by developing the technologies from the users' perspectives, which reflects the existence of strong causal relationships between information systems and user's behavior. As in other areas in social science the use of structural equation modeling (SEM) has rapidly increased in recent years especially in the MIS area. The SEM technique is important because it provides powerful ways to address key IS research problems. It also has a unique ability to simultaneously examine a series of casual relationships while analyzing multiple independent and dependent variables all at the same time. In spite of providing many benefits to the MIS researchers, there are some potential pitfalls with the analytical technique. The research objective of this study is to provide some guidelines for an appropriate use of SEM based on the assessment of current practice of using SEM in the MIS research. This study focuses on several statistical issues related to the use of SEM in the MIS research. Selected articles are assessed in three parts through the meta analysis. The first part is related to the initial specification of theoretical model of interest. The second is about data screening prior to model estimation and testing. And the last part concerns estimation and testing of theoretical models based on empirical data. This study reviewed the use of SEM in 164 empirical research articles published in four major MIS journals in Korea (APJIS, ISR, JIS and JITAM) from 1991 to 2007. APJIS, ISR, JIS and JITAM accounted for 73, 17, 58, and 16 of the total number of applications, respectively. The number of published applications has been increased over time. LISREL was the most frequently used SEM software among MIS researchers (97 studies (59.15%)), followed by AMOS (45 studies (27.44%)). In the first part, regarding issues related to the initial specification of theoretical model of interest, all of the studies have used cross-sectional data. The studies that use cross-sectional data may be able to better explain their structural model as a set of relationships. Most of SEM studies, meanwhile, have employed. confirmatory-type analysis (146 articles (89%)). For the model specification issue about model formulation, 159 (96.9%) of the studies were the full structural equation model. For only 5 researches, SEM was used for the measurement model with a set of observed variables. The average sample size for all models was 365.41, with some models retaining a sample as small as 50 and as large as 500. The second part of the issue is related to data screening prior to model estimation and testing. Data screening is important for researchers particularly in defining how they deal with missing values. Overall, discussion of data screening was reported in 118 (71.95%) of the studies while there was no study discussing evidence of multivariate normality for the models. On the third part, issues related to the estimation and testing of theoretical models on empirical data, assessing model fit is one of most important issues because it provides adequate statistical power for research models. There were multiple fit indices used in the SEM applications. The test was reported in the most of studies (146 (89%)), whereas normed-test was reported less frequently (65 studies (39.64%)). It is important that normed- of 3 or lower is required for adequate model fit. The most popular model fit indices were GFI (109 (66.46%)), AGFI (84 (51.22%)), NFI (44 (47.56%)), RMR (42 (25.61%)), CFI (59 (35.98%)), RMSEA (62 (37.80)), and NNFI (48 (29.27%)). Regarding the test of construct validity, convergent validity has been examined in 109 studies (66.46%) and discriminant validity in 98 (59.76%). 81 studies (49.39%) have reported the average variance extracted (AVE). However, there was little discussion of direct (47 (28.66%)), indirect, and total effect in the SEM models. Based on these findings, we suggest general guidelines for the use of SEM and propose some recommendations on concerning issues of latent variables models, raw data, sample size, data screening, reporting parameter estimated, model fit statistics, multivariate normality, confirmatory factor analysis, reliabilities and the decomposition of effects.