• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1340-1347
• /
• 2017

Utilization of Electric Vehicles (EVs) have been growing popularity in recent years due to increment in fuel price and lack of natural resources. Random unexpected charging by home EV charger in distribution is predicted in the future. The power quality problems such as fluctuation of power factor in a residential distribution network was explored with random EV chargers. This paper proposes a high-performance nonlinear sliding mode controller (SMC) for an EV charging system to compensate voltage distortions and to enhance the power factor against the unbalanced EV chargers. For the verification of the proposed scheme, MATLAB-Simulink simulations are performed on 22.9-kV grid. The results show that the proposed scheme can improve the power factor of a smart grid due to the EV chargers on the grid.

• Journal of Fisheries and Marine Sciences Education
• /
• v.25 no.4
• /
• pp.991-997
• /
• 2013

Distribution and occurrence of swimming crab, Portunus trituberculatus larvae were investigated in the mid-western coast of Korea in the Yellow Sea. P. trituberculatus larvae were collected in July and August from 2010 to 2012. Bongo net with 303 mesh was deployed once with a double oblique tow. Zoea I (ZI) densities were highest in all sampling months. Then densities of later larval stages decreased dramatically. In general, larval densities at the stations in northern parts and coastal areas were higher than those at the southern and offshore area. Because egg bearing seasons of P. trituberculatus in the study area are between April and August, larval densities, particularly, of ZI may be underestimated. Considering higher densities of ZI and lower ones of later stages, larvae may be transported to growing area and returned to the parental populations. Larval densities and sea surface temperature were not correlated.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.15
• /
• pp.6151-6154
• /
• 2014

A growing body of literature is evidence that identifying subtypes of high-risk human papillomavirus (HR-HPV) has impacted on various steps of cervical cancer prevention.Thus, it is mandatory to determine the background prevalence and distribution of HPV subtypes for designing and implementing area-specific management. The present study was conducted to evaluate prevalence and distribution of HPV subtypes among women aged 30-70 years living in Lampang, an area with a high incidence of cervical cancer, through use of a mobile screening unit. Of 2,000 women recruited in this study, 108 (5.40%, 95%CI: 4.45-6.48) were found to have HR-HPV infection. Risk was significantly correlated with age and number of partners. Singly or in combination, the most common genotype was HPV 52 (17.6%), followed by HPV 16 (14.81%), HPV 58 (13.89%), HPV 33 (11.11%), HPV 51 (11.11%), and HPV 56 (9.26%). HPV 18 was found in only 5.6% of cases. Together, HPV 16/18 were noted in approximately 20.4% of cases. Eighteen(16.67%) women were positive with multiple subtypes of HR-HPV. Co-infection most frequently involved HPV 16 or HPV 58. These findings have obvious implications for vaccine policy.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.60 no.4
• /
• pp.83-91
• /
• 2018

Land reclamation, coastal construction, coastline extension and port construction, all of which involve dredging, are increasingly required to meet the growing economic and societal demands in the coastal zone. During the land reclamation, a portion of landfills are lost from the desired location due to a variety of causes, and therefore prediction of sediment transport is very important for economical and efficient land reclamation management. In this study, laboratory disposal tests were performed using an open channel, and suspended sediment transport was analyzed according to flow velocity and grain size. The relationships between the average and standard deviation of the deposition distance and the flow velocity were almost linear, and the relationships between the average and standard deviation of deposition distance and the grain size were found to have high non-linearity in the form of power law. The deposition distribution of sediments was demonstrated to have log-normal distributions regardless of the flow velocity. Based on the experimental results, modeling of suspended sediment transport was performed using deep neural network, one of deep learning techniques, and the deposition distribution was reproduced through log-normal distribution.

• Journal of Distribution Science
• /
• v.18 no.8
• /
• pp.23-33
• /
• 2020

Purpose: In the digital age, visual cues in computer-mediated environments are becoming a very popular means of communication. Therefore, it is a very critical market for marketers to utilize for marketing communication and platform providers and manufacturers of mobile devices which create and distribute the visual cues While the prevalent research on visual cue consumption focuses on the positive side, the dark side of consuming visual cues has not been investigated. Therefore, in this research, the dark side of using visual cues, such as difficulties and problems in their application, will be investigated. Research design, data, and methodology: Due to the nature of this study, a netnography approach was adopted. Twitter which the users regularly utilise visual cues in their communications was a prime source for data of this research. Results: This research suggests that visual cue users experience anxiety about the subordination of expression and suffer from the myth of an ideal practice of expression. Conclusions: As the previous research emphasised the complementary role of visual cues, has failed to recognise the problems associated with the extensive and growing dependence on visual cues. This awareness demonstrates that we need to take a careful approach to visual cue usage.

• Journal of Korea Foresty Energy
• /
• v.2 no.2
• /
• pp.1-12
• /
• 1982

To study tile comparison of aboveground biomass of Pinus rigida Mill. of 18-year-old, plantations located in Whaseong, Yuseong and Wanju district were selected. Ten sample trees in each district selected taking account of DBH distribution were felled carefully to minimize loss of branches and stem analysed by 1m lag segment sectioned from base . The tree height and DBH were measured for sample trees in total growing within $200m^2$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two variables, $DBH^2$ and tree height, combined term were presented. The standing crops in the sample stand was estimated to be as much as 23.88, 54.09 and 42.68 tons of dry matter, above ground , per ha in Whaseong, Yuseong anf Wanju district respectively. Annual net production was estimated at 253,657 and 3.65 tons per ha per year respectively. The net assimilation rate was 1.65,1.95 and 1.81 kg/kg/yr in Whaseong, Yuseong and Wanju district respectively. The efficency of leaf to produce stem was 0.99, 1.12 and 1.30 kg/kg/yr respectively.

• Journal of Ecology and Environment
• /
• v.29 no.1
• /
• pp.17-22
• /
• 2006

Since the demands not only for value-added timber but the environmental functions of forests had been increased, native tree species has been, and is rapidly being replaced by foreign tree species in many parts of the world. However, the studies on population structure and regeneration characteristics of native tree species were not conducted enough. Regeneration of Kalopanax septemlobus growing among other hardwoods in natural forests is very difficult because of its low seed viability and germination rate. The study examined the distribution of mature trees of K. septemlobus and their regeneration pattern at the 1.12 ha study plot in natural deciduous broad-leaved forest of Mt. Jeombong. The density and mean DBH of K. septemlobus was 97 trees per ha and 32 cm, respectively. The spatial distribution of K. septemlobus showed a random pattern (aggregation index is 0.935) in the 1.12 ha study plot. The age of 90 trees among 99 sample trees of K. septemlobus ranged from 90 to 110 years and represented a single cohort, thus suggesting that K. septemlobus in advance regeneration has regenerated as a result of disturbances such as canopy opening.

• Journal of Distribution Research
• /
• v.1 no.1
• /
• pp.65-81
• /
• 1996

Despite the impressive economic growth over the past several decades, Korea's distribution sector has remained quite underdeveloped. Until recently, management of the marketing channels also has been staying at an unsophisticated level. The Korean marketing channel system is largely characterized by 1) undifferentiated channel types among the competing manufacturers, 2) dominance by the manufacturers over the other channel members, 3) high level of conflicts among the channel members, 4) inefficient marketing information system, and 5) lack of managers properly trained in channel operation and management. Currently, major change factors emerged and has begun to directly affect the Korean marketing channel system. The most salient changes surrounding the Korean marketing channel system are 1) complete opening of the marketing channels for the foreigners, 2) emergence and spread of new types of channels 3) adoption of advanced information technology by the various channel members, 4) increase in flexibility in production and supply systems, 5) shift of power toward the retailers away from the manufacturers, 6) growing trend for cooperation and alliance among the traditional marketing institutions. To these changes the manufacturers have been reacting, rather than proacting, mostly using defensive measures. The proactive measures that are recommended on behalf of the manufacturers include 1) installation of the strategic channel management system, 2) development of the skills for efficient interorganization management, 3) investing in efficient system for marketing information and logistics management, 4) more efficient management of brands, and 5) maintenance of price-competitiveness.

• Journal of Distribution Science
• /
• v.19 no.5
• /
• pp.61-68
• /
• 2021

Purpose: Retailing is one of the fastest-growing sectors in Vietnam. In the sight of foreign investors, the Vietnamese retailing market is very prospective. However, the current competition is very intensive, and retailers are keen on gaining new customers. Hence, Vietnamese retailers have paid more attention to customer loyalty. Saigon Co.op is one of the largest retailers in Vietnam, but its consumers have more choices over a retailer. As a result, Saigon Co.op has realized the significance of customer loyalty. This study aims to determine the factors impacting customer loyalty of Saigon Co.op supermarket in Vietnam. Research design, data and methodology: this study applied the multiple regression analysis with 250 samples collected from Saigon Co.op customers. The questionnaire is provided to respondents via Google Form, and the link is sent to the fan page of Co.op mart on Facebook. Two hundred eighty-seven samples were collected, but 37 samples were removed due to missing values. Exploratory Factor Analysis (EFA) and regression analysis are used for data analysis on SPSS software version 20. Results: The findings show all four determinants of Saigon Co.op's customer loyalty, including Product Quality, Brand Image, Price Strategy and Service Quality. Conclusions: managerial recommendations are provided for supermarkets to improve their customer loyalty in Vietnam and other emerging markets. Limitations and suggestions for further research are also discussed.

• Journal of Sensor Science and Technology
• /
• v.32 no.2
• /
• pp.75-81
• /
• 2023

The significance of gas sensors has been emphasized in various industries and applications, owing to the growing significance of environmental, social, and governance (ESG) management in corporate operations. In particular, the monitoring of hazardous gas leakages and detection of fugitive emissions have recently garnered significant attention across several industrial sectors. As industrial workplaces evolve to ensure the safety of their working environments and reduce greenhouse gas emissions, the demand for high-performance gas sensors in industrial sectors dealing with toxic substances is on the rise. However, conventional gas-sensing systems have limitations in monitoring fugitive gas leakages at both critical and subcritical concentrations in complex environments. To overcome these difficulties, recent studies in the field of gas sensors have employed techniques such as mobile robotic olfaction, remote optical sensing, chemical grid sensing, and remote acoustic sensing. This review highlights the significant progress made in various technologies that have enabled accurate and real-time mapping of gas distribution and localization of hazardous gas sources. These recent advancements in gas-sensing technology have shed light on the future role of gas-detection systems in industrial safety.