• Journal of Korean Society of Forest Science
• /
• v.110 no.3
• /
• pp.322-340
• /
• 2021

Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.41 no.2
• /
• pp.11-18
• /
• 2023

This study aims to distinguish what can be used in consideration of the national situation with Korea for Chinese Scenic and Historic Interest Areas, and the results are as follows; First, the Chinese Scenic and Historic Interest Areas expanded to the existing scenic cruise culture, travel, and tourism culture in the process of the influx of Western culture in the modern and contemporary era, and became popular as a travel destination. Accordingly, the Chinese government developed the tourism industry around the scenic sites, and thanks to the development of transportation and communication, the Scenic and Historic Interest Areas has become an important national heritage. This influenced the establishment of the system related to Scenic and Historic Interest Areas, and today, it is operated around the Scenic and Historic Interest Areas ordinance. Second, the designation of the Scenic and Historic Interest Areas is divided into the size of the site according to the area, and the process of selecting the Scenic and Historic Interest Areas classification, rating evaluation, and comprehensive value evaluation according to evaluation indicators and rating standards is carried out. Accordingly, according to the results of the classification, it is subdivided from the national level to the Scenic and Historic Interest Areas at the local level. Third, the central government is in charge of managing and supervising Scenic and Historic Interest Areas across the country, and the local government's construction department is in charge of supervising Scenic and Historic Interest Areas in the region. The management organization of Scenic and Historic Interest Areas established by local governments above the county level has a system that actually protects, utilizes, and manages Scenic and Historic Interest Areas. In addition, 14 detailed indicators are used to monitor Scenic and Historic Interest Areas. Based on these results, considering the application of the domestic scenic site policy, the method of developing the policy that has established the system from the perspective of the utilization of the people is worth considering. On the other hand, the evaluation of the designation and management system through the setting of various indicators has limitations in that it is difficult to secure objectivity in impressing or evaluating the landscape. Therefore, rather than blindly introducing quantified evaluation, it seems that guidance and promotion on how to expand consensus on scenic values and enjoy heritage should be prioritized.

• Journal of Service Research and Studies
• /
• v.12 no.1
• /
• pp.25-35
• /
• 2022

Covid-19, of which the first patient in Korea occurred in January 2020, has affected various fields. Of these, the tourism sector might havebeen hit the hardest. In particular, since tourism-based industrial structure forms the basis of the region, Gangwon-province, and the tourism industry is the main source of income for small businesses and small enterprises, the damage is great. To check the situation and extent of such damage, targeting the Chuncheon region, where public access is the most convenient among the Gangwon regions, one-day tours are possible using public transportation from Seoul and the metropolitan area, with a general image that low expense tourism is recognized as possible, this study conducted empirical analysis through data analysis. For this, the general status of the region was checked based on the visitor data of Chuncheon city provided by the tourist information system, and to check the levels ofinterest in 2019, before Covid-19, and in 2020, after Covid-19, by comparing keywords collected from the web service sometrend of Vibe Company Inc., a company specializing in keyword collection, with SK Telecom's T-map search site data, which in parallel provides in-vehicle navigation service and communication service, this study analyzed the general regional image of Chuncheon-city. In addition, by comparing data from two years by developing a tourism popularity index applying keywords and T-map search site data, this study examined how much the Covid-19 situation affected the level of interest of visitors to the Chuncheon area leading to actual visits using a data analysis approach. According to the results of big data analysis applying the tourism popularity index after designing the data mart, this study confirmed that the effect of the Covid-19 situation on tourism popularity in Chuncheon-city, Gangwon-provincewas not significant, and confirmed the image of tourist destinations based on the regional characteristics of the region. It is hoped that the results of this research and analysis can be used as useful reference data for tourism economic policy making.

• Korean Journal of Environmental Agriculture
• /
• v.34 no.2
• /
• pp.149-154
• /
• 2015

BACKGROUND: Yeast isolates associated with the leaves, stems, and flowers of the tiger lily needed to be identified using isolation methods that have previously been used effectively in yeast biotechnology. A culture-based approach was necessary for the isolation of many yeast strains associated with tiger lily. METHODS AND RESULTS: In this study, the homogenized leaves, stems, and flowers of tiger lily were spreaded onto GPY medium containing chloramphenicol, streptomycin, Triton X-100, and L-sorbose. A total of 82 yeast strains from the leaves, 94 and 97 yeast strains from the stems and flowers were isolated, respectively. Yeast isolates were identified by phylogenetic analysis based on internal transcribed spacer region sequencing. The yeast species isolated from the leaves comprised of 31 isolates of the genus Pseudozyma, 28 of Aureobasidium pullulans, and 11 of the genus Cryptococcus. Those isolated from the stems comprised of 40 of A. pullulans and 11 of Cryptococcus, and 95 of A. pullulans While, 1 isolate each of the genera Rhodotorula and Metschnikowia were isolated from the flowers. CONCLUSION: We identified site-specific yeast communities associated with tiger lily. These yeast isolates may have high potential for application in the field of biotechnology.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.3
• /
• pp.147-155
• /
• 2010

This study was conducted to investigate the benzene exposure levels in coal chemical and petrochemical refining industries during BTX turnaround (TA) processes where benzene was being produced. Three companies producing benzene were selected, one coal chemical and two petrochemical industries. TA processes were classified into three stages: shut down, maintenance, and start up. Data was analyzed by classifying the refining method into 2 groups (Petrochemistry, Coal chemistry) for 823 workers. Comparing the data from petrochemical industries with data from a coal chemical refining industry, while benzene concentration levels of long-term samples during TA were not statistically different (p> 0.05), those levels of short-term samples were significantly different (p< 0.001). About 4.79 % of data in petrochemical industries exceed the occupational exposure limits (OELs) of benzene, 1 ppm. In a coal refining methods, about 15.7% exceeded the benzene OELs. The benzene concentrations in maintenance and start up stage of TA for petrochemical refineries were higher than those in a coal chemical refinery (p <0.01). These findings suggest that the coal chemical refining site requires more stringent work practice controls compare to petrochemical refining sites during TA processes. Personal protective equipments including organic respirators should be used by TA workers to protect them from benzene overexposure.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.172-173
• /
• 2012

Currently GaN based LED is known to show high internal or external efficiency at low current range. However, this LED operation occurs at high current range and in this range, a significant performance degradation known as 'efficiency droop' occurs. Auger process, carrier leakage process, field effect due to lattice mismatch and thermal effects have been discussed as the causes of loss of efficiency, and these phenomena are major hindrance in LED performance. In order to investigate the main effects of efficiency loss and overcome such effects, it is essential to obtain relative proportion of measurements of internal quantum efficiency (IQE) and various radiative and nonradiative recombination processes. Also, it is very important to obtain radiative and non-radiative recombination times in LEDs. In this research, we measured the IQE of InGaN/GaN multiple quantum wells (MQWs) LEDs with PSS and Planar substrate using modified ABC equation, and investigated the physical mechanism behind by analyzing the emission energy, full-width half maximum (FWHM) of the emission spectra, and carrier recombination dynamic by time-resolved electroluminescence (TREL) measurement using pulse current generator. The LED layer structures were grown on a c-plane sapphire substrate and the active region consists of five 30 ${\AA}$ thick In0.15Ga0.85N QWs. The dimension of the fabricated LED chip was $800um{\times}300um$. Fig. 1. is shown external quantum efficiency (EQE) of both samples. Peak efficiency of LED with PSS is 92% and peak efficiency of LED with planar substrate is 82%. We also confirm that droop of PSS sample is slightly larger than planar substrate sample. Fig. 2 is shown that analysis of relation between IQE and decay time with increasing current using TREL method.

• Industry Promotion Research
• /
• v.5 no.4
• /
• pp.55-61
• /
• 2020

In conducting school violence counseling to solve school violence, this study studied the use of school violence counseling to solve school violence by forming a correct peer relationship. Through this study, we can see that peer relations are an important factor in preventing school violence in school violence counseling. The findings are as follows. First, school violence counseling should first protect and heal victims. The primary goal of school violence counseling should begin with consideration for the victims and be placed on the continuation of the victim's right peer relationship. That's how important peer relationships are. Second, not only victims of school violence counseling, but also perpetrators should be included in the list of counsels. In other words, there may be many cases where counseling is usually focused only on the victim. Therefore, the peer relationship can continue even after school violence, so customized counseling is needed not only for victims but also for perpetrators. Third, for school violence counseling, the recovery of peer relations and insight into life are important. Therefore, the focus should be on self-reflection and the restoration of relations between the parties, not on a disciplined or disciplined, controlled perspective. Fourth, we should recognize the importance of peer relations in school violence and activate the 'old counseling program'. Therefore, school violence counselors should optimize their programs by reflecting on-site needs so that they can act as emotional facilitators, problem solvers, and empathic cultural promoters in their roles. In conclusion, school violence counseling should basically be involved in peer relationships. School violence counseling should develop and implement programs focusing on the formation of proper peer relations in order to eradicate school violence.

• Journal of Digital Convergence
• /
• v.10 no.6
• /
• pp.133-140
• /
• 2012

This study starts from interests on an endeavor of each economy unit, especially the enterprises, for the survival and sustainability of themselves. Competition, how to get it, maintain it and advance it! Agreeing the perceivedness of industries, scholars and public; what the core competition of manufacturer is an competitiveness of product, this study focuses on the PLM system as the key solution for obtaining the competitiveness of product with reviewing the contents and studies of PLM formulated. PLM is highlighted as the one of top tier ICT solution for the product development domain of manufacturing industry today. First of all, this study deals with the opinion of actual work-site and management of our small&medium business for the benefits of PLM based on product development; the impact on the performances of management, which is the key objective of the existence of enterprises. In conclusion, the answers for these questionnaires shows positive perception of actual work-sites and managers for the PLM system. They agree some useful effects on shortening the term and downsizing the cost of product development due to Data integration and Process management, even if they have not full confidence on the effectiveness of the individual functionality of the PLM system.

• Korean Journal of Agricultural Science
• /
• v.41 no.4
• /
• pp.473-480
• /
• 2014

Upon setting up a dedicated plastic greenhouse for tomato cultivation developed by the Rural Development Administration on the Gyehwa reclaimed land, this study was aimed at analyzing the problems can be occurred in the installation of plastic greenhouse on reclaimed lands as well as finding out solutions for improvement. A relatively cheaper wooden pile was used in the installation in order to supplement the soft ground conditions. Based on the results of ground investigation of the installation site, both the allowable bearing capacity and pulling resistance of the wooden pile with a diameter of 150 mm and a length of 10 m were computed and came out to be 30.645 kN. It was determined that the values were enough to withstand the maximum compressive force (17.206 kN) and the pullout force (20.435 kN) that are generally applied to the greenhouse footing. There are three problems aroused in the process of greenhouse installation, and the corresponding countermeasures are as follow. First, due to the slightly bent shape of the wooden pile, there were phenomenon such as deviation, torsion, and fracture when driving the pile. This could be prevented by the use of the backhoe (0.2) rotating tongs, which are holding the pile, to drive the pile while pushing to the direction of the driving and fixing it until 5 m below ground and applying a soft vibrating pressure until the first 2 m. Second, there exists a concrete independent footing between the column of the greenhouse and the wooden pile driven to the underground water level. Since it is difficult to accurately drive the pile on this independent footing, the problem of footing baseplate used to fix the column being off the independent footing was occurred. In order to handle with this matter, the diameter of the independent footing was changed from 200 mm to 300 mm. Last, after films were covered in the condition that the reinforcing frame and bracing are not installed, there was a phenomenon of columns being pushed away by the strong wind to the maximum of $11m{\cdot}s^{-1}$. It is encouraged to avoid constructions in winter, and the film covering jobs always to be done after the frame construction is completely over. The height of the independent footing was measured for 9 months after the completion of the greenhouse installation, and it was found to be within the margin of error meaning that there was no subsidence. The extent to the framework distortion and the value of inclinometers as well showed not much alteration. In other words, the wooden pile was designed to have a sufficient bearing capacity.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.2
• /
• pp.191-197
• /
• 2017

The safety nature of construction industry differs from that of manufacturing sector. For instance, accident risk level dramatically varies at each phase of construction process. Korean Occupational and Health Safety Act has been regulated OHS expense and it contributed reducing accident risk and enhancing safety culture for many years. However, although current regulation guides to use OHS expense proportionate to construction progress, it still allows late use of the expense. This study was conducted for the purpose of presenting methods of estimating a step-by-step OHS expense rate required at each construction phase. In order to do provide proper OHS expense schedule, it analysed accident risk of each construction phase by sorting out 1439 cases of construction site fatality reports, and proposed a method of generating appropriate OHS expense scheme according to its construction work progress characteristics. Both linear and sigmoidal S-curve model were used for the analysis, and the latter generally requires earlier use of OHS expense. By comparing the estimated OHS expense use schedule with current criteria, more than 27%p early use of OHS expense is required for the prevention of accident.