• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.121-128
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• 2012

High resolution intertidal DEM is a basic material for science research like sedimentation/erosion by ocean current, and is invaluable in a monitoring of environmental changes and practical management of coastal wetland. Since the intertidal zone changes rapidly by the inflow of fluvial debris and tide condition, remote sensing is an effective tool for observing large areas in short time. Although radar interferometry is one of the well-known techniques for generating high resolution DEM, conventional repeat-pass interferometry has difficulty on acquiring enough coherence over tidal flat due to the limited exposure time and the rapid changes in surface condition. In order to overcome these constraints, we tested the feasibility of radar interferometry using Cosmo-SkyMed tandem-like one-day data and ERS-ENVISAT cross tandem data with very short revisit period compared to the conventional repeat pass data. Small temporal baseline combined with long perpendicular baseline allowed high coherence over most of the exposed tidal flat surface in both observations. However the interferometric phases acquired from Cosmo-SkyMed data suffer from atmospheric delay and changes in soil moisture contents. The ERS-ENVISAT pair, on the other hand, provides nice phase which agree well with the real topography, because the atmospheric effect in 30-minute gap is almost same to both images so that they are cancelled out in the interferometric process. Thus, the cross interferometry with very small temporal baseline and large perpendicular baseline is one of the most reliable solutions for the intertidal DEM construction which requires very accurate mapping of the elevation.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.2
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• pp.59-69
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• 2019

This study was carried out to investigate effects of soil water content on growth and antioxidative enzymes activity of tomato seedlings during the nursery period. The water stress significantly damages morphological, physiological, and biochemical activities in plants. The seedlings planted with soil on the tray were irrigated and categorized into 3 groups with 30 g, 40 g, and 50 g of plant-soil weight. After then, the changes in weight of the soil and the seedling were measured evey 2 hours for 4 days and the leaf temperature was measured with the thermal-camera at the same time. The antioxidant enzymes were measured to determine the level of stress using all of the seedling samples. The result showed that the decrease of soil weight in the day time was faster than that in the night time, but there was no significant difference in the weight loss of the seedlings and soil among the groups. However, the group with 50 g of wight showed the highest SOD and POD contents. This is considered that the continuously wet soil on the root zone of the seedlings caused more stress for the seedlings. Therefore, it is concluded that the excess moisture content causes stress to stimulate the secretion of antioxidant enzymes, and the effect of stress is required to be analyzed comprehensively using environmental data and also the physiological data that are collected over a longer period.

• Journal of Information Technology Applications and Management
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• v.26 no.4
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• pp.51-69
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• 2019

One of the most considerate phenomena of the era of the Fourth Industrial Revolution is the use of digital devices. Digitalization is rapidly advancing through all areas of industry and life. Customer journey with digitalization is looking totally different from previous customer journey. The research targets were users of fashion, automobiles, cosmetics and online shopping malls. We analyzed 300 people for each valid questionnaire. The results of the study are as follows. First, it has been proven that digital experience affects positive (+) impact on purchasing intention and positive (+) impact on recommending intention and negative impact (-) on switching intent and subsequently affects positive impact (+) to purchase and incase of switching intent, negative impact (-) to purchase. Unlike traditional methods such as SPC(Service Profit Chain), the Digital experience to Purchase process Chain (DPC) has been identified to be suitable in the digital age. Second, the digital satisfied group (5 score-very satisfaction) has shown same result as above. However the digital neutral group (even though 4 score- satisfaction in five-point scale), specially in a highly competitive industry, has different from the satisfied group and 3 score-normal is same as dissatisfied group. It means that this group is that If there is a high level of attractiveness of substitute goods, there is a high possibility of switching them. It has supported Jones and Sasser [1995] that there have been two types of loyalty of true long-term loyalty and what we call false loyalty in the highly competitive industry zone which is commoditization or low differentiation, many substitutes, low cost of switching. Identifying true loyalty and false loyalty is crucial to establishing a customer experience strategy. it is necessary to actively utilize long-term digital experiences strategy to increase the total satisfaction of digital experience through all of customer purchasing journey in order to enhance the digital customer experience. It is difficult to see the effect as a one-time event. It should be scaled over the entire customer purchase process over a long period of time, which can positively affect purchase intention, recommendation intention, and conversion intention. This is also why it is difficult for second-runners to overtake first-runners in a short period.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.277-291
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• 2012

Aquaculture is challenged by a number of constraints with future efforts towards sustainable production. Global climate change has a potential damage to the sustainability by changing environmental surroundings unfavorably. The damaging parameters identified are water temperature, sea level, surface physical energy, precipitation, solar radiation, ocean acidification, and so on. Of them, temperature, mostly temperature elevation, occupies significant concern among marine ecologists and aquaculturists. Ocean acidification particularly draws shellfish aquaculturists' attention as it alters the marine chemistry, shifting the equilibrium towards more dissolved CO2 and hydrogen ions ($H^+$) and thus influencing signaling pathways on shell formation, immune system, and other biological processes. Temperature elevation by climate change is of double-sidedness: it can be an opportunistic parameter besides being a generally known damaging parameter in aquaculture. It can provide better environments for faster and longer growth for aquaculture species. It is also somehow advantageous for alleviation of aquaculture expansion pressure in a given location by opening a gate for new species and aquaculture zone expansion northward in the northern hemisphere, otherwise unavailable due to temperature limit. But in the science of climate change, the ways of influence on aquaculture are complex and ambiguous, and hence are still hard to identify and quantify. At the same time considerable parts of our knowledge on climate change effects on aquaculture are from the estimates from data of fisheries and agriculture. The consequences may be different from what they really are, particularly in the temperature region. In reality, bivalves and tunicates hung or caged in the longline system are often exposed to temperatures higher than those they encounter in nature, locally driving the farmed shellfish into an upper tolerable temperature extreme. We review recent climate change and following environment changes which can be factors or potential factors affecting shellfish aquaculture production in the temperate region.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.2
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• pp.63-72
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• 2017

Purpose: The purpose of this study is to review the material handling system of the Airborne Infection Isolation Hospitals which is the one of the key elements of infection control and to improve the basic data for the planning and design of those facilities. Methods: Research was conducted by literature reviews and case studies for the material handling system of domestic and foreign Isolation hospitals. Results: The result of this study can be summarized into three points. First, a general isolation unit and a high level isolated unit need to be distinguished in terms of efficiency and safety. In particular, it is desirable that a high level isolated unit have to completely separate clean and soiled circulations, and soiled corridor should be installed by those means. By doing this, the medical staff can observe patient rooms and supply clean materials directly in the clean zone without wearing PPE, so that safety and work efficiency can be improved at the same time. Second, for the safe disposal of wastes, it is desirable to install a dedicated sterilizer per ward and sterilize it at least in the ward. In addition, It is desirable to install a central waste treatment room and a dedicated soiled corridor in consideration of the inadequate handling capacity and emergency situation. Third, the characteristics of material flow chart in the negative pressured isolation hospitals and the corresponding material handling system have been presented. Implications: Infection control is very important in safety, but it is necessary to respond to the symptoms of the patient.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.637-643
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• 2008

When planning outfall system, the first target cif design is to maximize initial dilution of discharge effluent. To achieve the target effectively, the characteristics of mixing phenomenon between ambient and discharged water should be analyzed. Especially the analysis at the Near-Field-Region(NFR) as initial dilution zone should be preceded. Usually, the initial behavior of effluent through outfall system is rising toward the surface due to mixing with ambient water for heat discharge and sinking toward the bottom due to the difference of density for brine discharge. After mixed with eddies accompanied by the ambient water, the plumes are showing the same density and internal current pattern by advection and diffusion. Until recently, lots of studies are being carried out for the optimum design of outfall system. but it is difficult to find any studies of heat and brine discharge at the same time. Therefore, this study is hoped to provide some basic data for optimum design of outfall system.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.261-273
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• 2011

Recently, the demands for steel frame are increasing because of the trend and due to the demand for bigger and higher buildings. In the analysis of typical steel frame, connections are based on the idealized fixed or pinned connection. A fixed connection assumes that the relative angle of each member before deformation is the same after the transformation. Therefore, the stiffener reinforces the connection to sufficient rigidity and stability of the panel zone. In the economical aspect, however, the necessity of connection that the stiffener reinforcement has omitted is increasing due to the excessive production as well as labor costs of connection. In contrast, pinned connection is assumed that bending moments between the beams and columns do not transfer to each member. This is easy to make in the plant and the construction is simple. However, the structural efficiency is reduced in pinned connection because connection cannot transfer moments. The introduction of this semirigid process can decide efficient cross-sectional dimensions that promote ease in the course of structural erection, as performed by members in the field-a call for safety in the entire frame. Therefore, foreign countries exert efforts to study the practical behavior and the results are applied to criterion. This paper analyzes the semirigid connection of domestic steel by design specifications of AISC/LRFD and make data bank that pertain to each steel. After wards, the results are compared to those of idealized connection; at the same time, this paper presents a design method that matches economic efficiency, end-fixity, and rotational stiffness.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.233-254
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• 2017

The purpose of this study is to analyze the main factors influencing the severity of traffic accidents and to visualize spatiotemporal characteristics of traffic accidents in Seoul. To do this, we collected the traffic accident data that occurred in Seoul for four years from 2012 to 2015, and classified as slight, serious, and death traffic accidents according to the severity of traffic accidents. The analysis of spatiotemporal characteristics of traffic accidents was performed by kernel density analysis, hotspot analysis, space time cube analysis, and Emerging HotSpot Analysis. The factors affecting the severity of traffic accidents were analyzed using decision tree model. The results show that traffic accidents in Seoul are more frequent in suburbs than in central areas. Especially, traffic accidents concentrated in some commercial and entertainment areas in Seocho and Gangnam, and the traffic accidents were more and more intense over time. In the case of death traffic accidents, there were statistically significant hotspot areas in Yeongdeungpo-gu, Guro-gu, Jongno-gu, Jung-gu and Seongbuk. However, hotspots of death traffic accidents by time zone resulted in different patterns. In terms of traffic accident severity, the type of accident is the most important factor. The type of the road, the type of the vehicle, the time of the traffic accident, and the type of the violation of the regulations were ranked in order of importance. Regarding decision rules that cause serious traffic accidents, in case of van or truck, there is a high probability that a serious traffic accident will occur at a place where the width of the road is wide and the vehicle speed is high. In case of bicycle, car, motorcycle or the others there is a high probability that a serious traffic accident will occur under the same circumstances in the dawn time.

• Journal of Korea Water Resources Association
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• v.53 no.2
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• pp.107-119
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• 2020

This study analyzed past drought characteristics based on the observed rainfall data and performed a long-term outlook for future extreme droughts using Representative Concentration Pathways 8.5 (RCP 8.5) climate change scenarios. Standardized Precipitation Index (SPI) used duration of 1, 3, 6, 9 and 12 months, a meteorological drought index, was applied for quantitative drought analysis. A single long-term time series was constructed by combining daily rainfall observation data and RCP scenario. The constructed data was used as SPI input factors for each different duration. For the analysis of meteorological drought observed relatively long-term since 1954 in Korea, 12 rainfall stations were selected and applied 10 general circulation models (GCM) at the same point. In order to analyze drought characteristics according to climate change, trend analysis and clustering were performed. For non-stationary frequency analysis using sampling technique, we adopted the technique DEMC that combines Bayesian-based differential evolution ("DE") and Markov chain Monte Carlo ("MCMC"). A non-stationary drought frequency analysis was used to derive Severity-Duration-Frequency (SDF) curves for the 12 locations. A quantitative outlook for future droughts was carried out by deriving SDF curves with long-term hydrologic data assuming non-stationarity, and by quantitatively identifying potential drought risks. As a result of performing cluster analysis to identify the spatial characteristics, it was analyzed that there is a high risk of drought in the future in Jeonju, Gwangju, Yeosun, Mokpo, and Chupyeongryeong except Jeju corresponding to Zone 1-2, 2, and 3-2. They could be efficiently utilized in future drought management policies.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.136-150
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• 2022

In this study, a comparative review was conducted on how to use RGB images to obtain river topographic information, which is one of the most essential data for eco-friendly river management and flood level analysis. In terms of the topographic information of river zone, to obtain the topographic information of flow section is one of the difficult topic, therefore, this study focused on estimating the river topographic information of flow section through RGB images. For this study, the river topography surveying was directly conducted using ADCP and RTK-GPS, and at the same time, and orthomosiac image were created using high-resolution images obtained by drone photography. And then, the existing developed regression equations were applied to the result of channel topography surveying by ADCP and the band values of the RGB images, and the channel bathymetry in the study area was estimated using the regression equation that showed the best predictability. In addition, CCHE2D flow modeling was simulated to perform comparative verification of the topographical informations. The modeling result with the image-based topographical information provided better water depth and current velocity simulation results, when it compared to the directly measured topographical information for which measurement of the sub-section was not performed. It is concluded that river topographic information could be obtained from RGB images, and if additional research was conducted, it could be used as a method of obtaining efficient river topographic information for river management.