• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1111-1123
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• 2023

In recent times, semantic image segmentation methods using deep learning models have been widely used for monitoring changes in surface attributes using remote sensing imagery. To enhance the performance of various UNet-based deep learning models, including the prominent UNet model, it is imperative to have a sufficiently large training dataset. However, enlarging the training dataset not only escalates the hardware requirements for processing but also significantly increases the time required for training. To address these issues, transfer learning is used as an effective approach, enabling performance improvement of models even in the absence of massive training datasets. In this paper we present three transfer learning models, UNet-ResNet50, UNet-VGG19, and CBAM-DRUNet-VGG19, which are combined with the representative pretrained models of VGG19 model and ResNet50 model. We applied these models to building extraction tasks and analyzed the accuracy improvements resulting from the application of transfer learning. Considering the substantial impact of learning rate on the performance of deep learning models, we also analyzed performance variations of each model based on different learning rate settings. We employed three datasets, namely Kompsat-3A dataset, WHU dataset, and INRIA dataset for evaluating the performance of building extraction results. The average accuracy improvements for the three dataset types, in comparison to the UNet model, were 5.1% for the UNet-ResNet50 model, while both UNet-VGG19 and CBAM-DRUNet-VGG19 models achieved a 7.2% improvement.

• The Journal of KAIRB
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• v.5 no.2
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• pp.43-50
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• 2023

Purpose: Due to the stringency of regulations related to clinical research, researchers face various requirements in the Institutional Review Board (IRB) review process. Specifically, they encounter time constraints and administrative burdens. In order to cultivate a more favorable review culture and establish a robust research environment, it is necessary to analyze researchers' perceptions of the IRB review. Therefore, this study aims to assess researchers' overall experiences with the IRB and identify researchers' educational needs and demands for research-related policies. Methods: A semistructured questionnaire with 34 items was developed and refined in consultation with advisors from IRB and Human Research Protection Program (HRPP). The questionnaire was distributed via an online survey to researchers with experience in IRB review. The survey covered general characteristics, satisfaction with the IRB review process (rated on a 10-point scale), experiences with IRB review, HRPP policy demands. Results: The study's descriptive statistics revealed a moderate satisfaction level (average rating, 6.75 out of 10) with the IRB review. Researchers from clinical medicine and other disciplines showed similar satisfaction scores of 6.65 and 6.87, respectively. However, respondents with over 5 years of research experience expressed higher satisfaction (mean score, 7.03) compared to those with less experience (mean score, 6.57). Institutional support was emphasized for improving the IRB review process. Certain training topics generated higher demands for addressing frequently raised IRB issues among minor discipline researchers compared to clinical medicine (p=0.017). Conclusion: We conducted an analysis of researchers' perceptions regarding the IRB as well as their demands concerning educational and HRPP policies. It is imperative to address the pinpointed areas for enhancement and integrate a range of perspectives in order to effectively cultivate a robust research ethics culture and ensure comprehensive participant protection.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.61-81
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• 2024

eCall system assists traffic accident victims by connecting emergency rescue institutions with accurate accident information, helping them to identify the on-site situation in the event of a traffic accident. The purpose of this paper is to develop a Korean eCall system that reflects the requirements of domestic emergency rescue institutions and to analyze the expected effects through an integrated demonstration. The results of an integrated demonstration indicated that the communication success rate between the eCall IVS and the call center was 99.25%, and the average location information error was 1.2 m. In particular, it has been confirmed that the average location information error is less than 21.6 meters, as assessed by the Korea Communications Commission when evaluating the accuracy of domestic emergency rescue location information. When the eCall system was introduced, it was confirmed that the time from traffic accidents to hospital arrival could be shortened by 3 m 38 s for highways and 1 m 22 s for general roads. By it to traffic deaths from 2005 to 2022, it was analyzed that the number of fatalities decreased by 82,662, resulting in a reduction of approximately social costs.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.65-76
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• 2024

With the recent activation of the offshore wind power industry, there has been a development of power plants with a scale exceeding 400MW, comparable to traditional thermal power plants. Renewable energy, characterized by intermittency depending on the energy source, is a prominent feature of modern renewable power generation facilities, which are structured based on controllable inverter technology. As the integration of renewable energy sources into the grid expands, the grid codes for power system connection are progressively becoming more defined, leading to active discussions and evaluations in this area. In this paper, we propose a method for selecting optimal reactive power compensation capacity when multiple offshore wind farms are integrated and connected through a shared interconnection facility to comply with grid codes. Based on the requirements of the grid code, we analyze the reactive power compensation and excessive stability of the 400MW wind power generation site under development in the southwest sea of Jeonbuk. This analysis involves constructing a generation site database using PSS/E (Power System Simulation for Engineering), incorporating turbine layouts and cable data. The study calculates reactive power due to charging current in internal and external network cables and determines the reactive power compensation capacity at the interconnection point. Additionally, static and dynamic stability assessments are conducted by integrating with the power system database.

• Information Systems Review
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• v.19 no.2
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• pp.185-209
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• 2017

In modern society, crime records have been digitized. Digital information is difficult to distinguish from original information, but the former is easy to modulate. This situation explains the increasing importance of digital forensics. However, digital forensic has several inefficiencies because of the rapid development of technology, unclear jurisdiction, and tool errors. This study surveyed digital forensic specialists and derived the priority of domestic digital forensic issues by redefining 17 issues in digital forensics from Brungs-Jamieson study in Australia. The present study was divided into four groups, namely, police, government and public corporations, private companies, and legal groups. The study could compare and analyze comparative analysis of existing studies in Australia and the US. This study can also examine differences in the results of each group in Korea. Thus, the key issues in Korea were derived as "Requirements to 'Fire Up' Original." The differences of the three groups in terms of legal issues were then identified. This finding enables us to understand differences in priorities and importance between groups and countries.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.215-235
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• 1996

The thermal analysis by mathematical model simulation makes it possible to reasonably predict heating and/or cooling requirements of certain greenhouses located under various geographical and climatic environment. It is another advantages of model simulation technique to be able to make it possible to select appropriate heating system, to set up energy utilization strategy, to schedule seasonal crop pattern, as well as to determine new greenhouse ranges. In this study, the control pattern for greenhouse microclimate is categorized as cooling and heating. Dynamic model was adopted to simulate heating requirements and/or energy conservation effectiveness such as energy saving by night-time thermal curtain, estimation of Heating Degree-Hours(HDH), long time prediction of greenhouse thermal behavior, etc. On the other hand, the cooling effects of ventilation, shading, and pad ||||&|||| fan system were partly analyzed by static model. By the experimental work with small size model greenhouse of 1.2m$\times$2.4m, it was found that cooling the greenhouse by spraying cold water directly on greenhouse cover surface or by recirculating cold water through heat exchangers would be effective in greenhouse summer cooling. The mathematical model developed for greenhouse model simulation is highly applicable because it can reflects various climatic factors like temperature, humidity, beam and diffuse solar radiation, wind velocity, etc. This model was closely verified by various weather data obtained through long period greenhouse experiment. Most of the materials relating with greenhouse heating or cooling components were obtained from model greenhouse simulated mathematically by using typical year(1987) data of Jinju Gyeongnam. But some of the materials relating with greenhouse cooling was obtained by performing model experiments which include analyzing cooling effect of water sprayed directly on greenhouse roof surface. The results are summarized as follows : 1. The heating requirements of model greenhouse were highly related with the minimum temperature set for given greenhouse. The setting temperature at night-time is much more influential on heating energy requirement than that at day-time. Therefore It is highly recommended that night- time setting temperature should be carefully determined and controlled. 2. The HDH data obtained by conventional method were estimated on the basis of considerably long term average weather temperature together with the standard base temperature(usually 18.3$^{\circ}C$). This kind of data can merely be used as a relative comparison criteria about heating load, but is not applicable in the calculation of greenhouse heating requirements because of the limited consideration of climatic factors and inappropriate base temperature. By comparing the HDM data with the results of simulation, it is found that the heating system design by HDH data will probably overshoot the actual heating requirement. 3. The energy saving effect of night-time thermal curtain as well as estimated heating requirement is found to be sensitively related with weather condition: Thermal curtain adopted for simulation showed high effectiveness in energy saving which amounts to more than 50% of annual heating requirement. 4. The ventilation performances doting warm seasons are mainly influenced by air exchange rate even though there are some variations depending on greenhouse structural difference, weather and cropping conditions. For air exchanges above 1 volume per minute, the reduction rate of temperature rise on both types of considered greenhouse becomes modest with the additional increase of ventilation capacity. Therefore the desirable ventilation capacity is assumed to be 1 air change per minute, which is the recommended ventilation rate in common greenhouse. 5. In glass covered greenhouse with full production, under clear weather of 50% RH, and continuous 1 air change per minute, the temperature drop in 50% shaded greenhouse and pad ＆ fan systemed greenhouse is 2.6$^{\circ}C$ and.6.1$^{\circ}C$ respectively. The temperature in control greenhouse under continuous air change at this time was 36.6$^{\circ}C$ which was 5.3$^{\circ}C$ above ambient temperature. As a result the greenhouse temperature can be maintained 3$^{\circ}C$ below ambient temperature. But when RH is 80%, it was impossible to drop greenhouse temperature below ambient temperature because possible temperature reduction by pad ||||&|||| fan system at this time is not more than 2.4$^{\circ}C$. 6. During 3 months of hot summer season if the greenhouse is assumed to be cooled only when greenhouse temperature rise above 27$^{\circ}C$, the relationship between RH of ambient air and greenhouse temperature drop($\Delta$T) was formulated as follows : $\Delta$T= -0.077RH＋7.7 7. Time dependent cooling effects performed by operation of each or combination of ventilation, 50% shading, pad ＆ fan of 80% efficiency, were continuously predicted for one typical summer day long. When the greenhouse was cooled only by 1 air change per minute, greenhouse air temperature was 5$^{\circ}C$ above outdoor temperature. Either method alone can not drop greenhouse air temperature below outdoor temperature even under the fully cropped situations. But when both systems were operated together, greenhouse air temperature can be controlled to about 2.0-2.3$^{\circ}C$ below ambient temperature. 8. When the cool water of 6.5-8.5$^{\circ}C$ was sprayed on greenhouse roof surface with the water flow rate of 1.3 liter/min per unit greenhouse floor area, greenhouse air temperature could be dropped down to 16.5-18.$0^{\circ}C$, whlch is about 1$0^{\circ}C$ below the ambient temperature of 26.5-28.$0^{\circ}C$ at that time. The most important thing in cooling greenhouse air effectively with water spray may be obtaining plenty of cool water source like ground water itself or cold water produced by heat-pump. Future work is focused on not only analyzing the feasibility of heat pump operation but also finding the relationships between greenhouse air temperature(T$_{g}$ ), spraying water temperature(T$_{w}$ ), water flow rate(Q), and ambient temperature(T$_{o}$).

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.72-84
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• 2020

The purpose of this study is to provide a reference for the development of forest therapy programs for subfertile women. This exploratory study identifies the emotional characteristics of subfertile women and the demands for forest therapy according to the emotional characteristics and provides basic data for the development and operation of forest therapy programs. This study surveyed 200 subfertile women who visited a subfertility hospital in Seoul on 33 items of subfertile women's emotional characteristics and requirements of forest therapy programs. We conducted the frequency analysis, cross-analysis, and one-way ANOVA to determine the correlation and importance between the emotional characteristics of subfertile women and the demands for forest therapy programs using the SPSS 21.0 program. Emotional traits of subfertile women included pressure on pregnancy, anxiety/fear, depression, hopelessness, helplessness, loneliness, sadness, shame/guilt, impatience/frustration, and anger/hypersensitivity. Of these traits, pressure on pregnancy, depression, hopelessness, helplessness, loneliness, sadness, anger/hypersensitivity, and anxiety/fear were particularly high among subfertile women. The demands for forest therapy programs also differed according to the emotional characteristics of subfertile women. There was a significant difference in the operation mode of the subfertile couple's forest therapy program according to the pressure, shame, and guilt of pregnancy. There was a significant difference in the experience of participating in a program according to anxiety and fear and in the reason for not being able to participate in the forest therapy program according to depression, hopelessness, helplessness, loneliness, and sadness. There was a significant difference in couples participating the in the forest therapy program according to impatience and frustration. There was a significant difference in the experience of participating in the forest therapy program and the effect of self-help groups through the forest therapy program for subfertile women according to anger and hypersensitivity. We expect that the results of this study would be useful as the reference data for developing forest therapy programs for the improvement of the mental health of subfertile women.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.584-596
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• 2008

Purpose : This study was conducted to investigate treatment compliance and related factors in pediatric patients. Methods : Three hundred and fifty-five patients diagnosed with various acute diseases at a teaching hospital or clinic in October 2003 were enrolled. Data were analyzed using the Health Belief Model, which includes items on self-efficacy and family assistance. Results : The study found that 62.9% of pediatric patients adhered faithfully to agreed-upon hospital revisits, 41.6% complied with dose timings instructions, 65.8% precisely took medication, and 27.2% complied with all of these requirements. According to ${\chi}^2$ test analysis, the factors found to be related to therapeutic compliance (the taking of medicines requested) were; susceptibility, severity, benefit, barriers, mother's self-efficacy, and family assistance (P<.05). Multiple logistic analysis and path analysis showed that susceptibility, severity, barriers, and mother's self-efficacy were related to therapeutic compliance (P<.05). Moreover, mother's self-efficacy was identified as the most important factor. Conclusion : To improve therapeutic compliance among pediatric patients, parental education is necessary, and a health care professional must take a thorough history of how the medication was taken before it is assumed that treatment failure is attributable to the medication prescribed. Furthermore, the type of device recommended for dosing should be determined by clinicians. In addition, it is important that pediatric medications be discussed in relation to their palatability and internal acceptability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.1-8
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• 2017

As the IT environment becomes more sophisticated, various threats and their associated serious risks are increasing. Threats such as DDoS attacks, malware, worms, and APT attacks can be a very serious risk to enterprises and must be efficiently managed in a timely manner. Therefore, the government has designated the important system as the main information communication infrastructure in consideration of the impact on the national security and the economic society according to the 'Information and Communication Infrastructure Protection Act', which, in particular, protects the main information communication infrastructure from cyber infringement. In addition, it conducts management supervision such as analysis and evaluation of vulnerability, establishment of protection measures, implementation of protection measures, and distribution of technology guides. Even now, security consulting is proceeding on the basis of 'Guidance for Evaluation of Technical Vulnerability Analysis of Major IT Infrastructure Facilities'. There are neglected inspection items in the applied items, and the vulnerability of APT attack, malicious code, and risk are present issues that are neglected. In order to eliminate the actual security risk, the security manager has arranged the inspection and ordered the special company. In other words, it is difficult to check against current hacking or vulnerability through current system vulnerability checking method. In this paper, we propose an efficient method for extracting diagnostic data regarding the necessity of upgrading system vulnerability check, a check item that does not reflect recent trends, a technical check case for latest intrusion technique, a related study on security threats and requirements. Based on this, we investigate the security vulnerability management system and vulnerability list of domestic and foreign countries, propose effective security vulnerability management system, and propose further study to improve overseas vulnerability diagnosis items so that they can be related to domestic vulnerability items.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.217-224
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• 2008

In deep geological disposal system, the integrity of a disposal canister having spent fuels is very important factor to assure the safety of the repository system. This disposal canister is one element of the engineered barriers to isolate and to delay the radioactivity release from human beings and the environment for a long time so that the toxicity does not affect the environment. The main requirement in designing the deep geological disposal system is to keep the buffer temperature below 100$^{\circ}C$ by the decay heat from the spent fuels in the canister in order to maintain the integrity of the buffer material. Also, the disposal canister can endure the hydraulic pressure in the depth of 500 m and the swelling pressure of the bentonite as a buffer. In this study, new concept of the disposal canister for the CANDU spent fuels which were considered to be disposed without any treatment was developed and the thermal stability and the structural integrity of the canister were analysed. The result of the thermal analysis showed that the temperature of the buffer was 88.9$^{\circ}C$ when 37 years have passed after emplacement of the canister and the spacings of the disposal tunnel and the deposition holes were 40 m and 3 m, respectively. In the case of structural analysis, the result showed that the safety factors of the normal and the extreme environment were 2.9 and 1.33, respectively. So, these results reveal that the canister meets the thermal and the structural requirements in the deep geological disposal system.