• Journal of the Korea Institute of Building Construction
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• v.22 no.3
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• pp.305-316
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• 2022

Domestic construction companies have difficulty in establishing strategies when entering overseas markets because they do not have an overseas construction economic sentiment index to refer to for data on overseas construction prospects. Considering that the fluctuation of overseas construction orders over the past decade has been substantial and large companies and SMEs are actively advancing overseas, this study developed an evaluation model for an overseas construction business sentiment index to grasp the economic experience of overseas construction companies. In 2021 Korean companies earned 30.6 billion in overseas construction contracts, 87% the level of the previous year, despite difficulties such as COVID-19 and low oil prices, thanks to efforts by construction companies to strengthen their strategies for entry, such as regional diversification, and government support for winning orders. Since the overseas construction industry fluctuates greatly due to changes in the international environment, it is necessary to investigate and analyze the economic sentiment index of overseas construction companies. In particular, despite the increase in overseas expansion of small and medium-sized construction companies and engineering companies, the provision of information on the overseas construction market sentiment index is insufficient, limiting the establishment of strategies for overseas construction expansion. Therefore, this study intends to develop an overseas construction market sentiment index model that can understand the economic sentiment of overseas construction companies, provide a forecast for overseas construction, and use it to establish overseas construction strategies and policies.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.83-94
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• 2022

In order to actively prepare to frost damage that occurs in the process of growing crops, the spatial and temporal distribution of frost occurrence in South Korea was derived using frost observation data from 20 regions over the past 21 years (2000~2020). The main products are the number of frost days, first frost day, and last frost day by region. And the climatic trends of these results were identified by performing the Mann-Kendall trend test and Sen's slope estimator. In South Korea, a lot of frost occurs in the inland area to the west of the Taebaek and Sobaek Mountains. Relatively closer to the coastal area, the number of frost days is small, the first frost day is slow, and the last frost day is early. The east coast region has fewer frost days, the first frost day is later, and the last frost day is earlier than the west coast region. The southern sea, the southeastern sea region, and the island region rarely experience frost. As a result of the annual time series trend analysis, although South Korea is a country where climate warming is progressing, there was no trend in reducing the number of frost days and slowing the first frost day, and it was found that the last frost day is delayed by 0.5 days per year.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.92-99
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• 2021

Light-scattering fine particulate matter monitors can measure particulate matter (PM) concentrations in every second and can be designed in a portable size. They can measure the concentrations of various PM sizes (PM_1.0, PM_2.5, PM_4.0 and PM₁₀) with a single sensor. They measure the number and size of particulate matters and convert them to weight per volume (concentration). These devices show a large error for asian dust. This paper proposes a scheme that compensates the PM_2.5 concenstration error for asian dust by multiple linear regression machine learning in light-scattering PM monitors. This scheme can be effective with only two or three types of PM sizes. The experimental results compare a beta-ray PM monitor of national institute of environmental research and a light-scattering PM monitor during a month. The correlation coefficient (R²) of theses two devices was 0.927 without asian dust, but it was 0.763 due to asian dust during the entire experimental period and improved to 0.944 by the proposed machine learning.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.275-284
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• 2022

Changes in air temperature, CO₂ concentration and precipitation due to climate change are expected to have a significant impact on soybean productivity. This study was conducted to evaluate the climate change impact on growth and development of determinate soybean cultivar in the southern parts of Korea. The high temperature during vegetative period, which does not accompany the increase of CO₂ concentration, increased the canopy photosynthetic rate in soybean, but after flowering, the high temperature above the optimal ranges interrupts the photosynthetic metabolism. In yield and yield components, high temperature reduced both the pod and seed number and single seed weight, resulting in a reduction of total seed yield. On the other hand, the increase in CO₂ concentration dramatically increased the canopy photosynthetic rate over the whole growth period. In addition, high CO₂ concentration increased the number of pods and seeds, which had a positive effect on total seed yield. Under concurrent elevation of air temperature and CO₂ concentration, canopy photosynthesis increased significantly, but enhanced canopy photosynthesis did not lead to an increase in soybean seed yield. The increase in biomass and branch by enhanced canopy photosynthesis seems to be attributed to an increase in the total number of pods and seeds per plant, which compensates for the negative effects of high temperature on pod development. However, Single seed weight tended to decrease rapidly by high temperature, regardless of CO₂ concentration level. Elevated CO₂ concentration did not compensate for the poor distribution of assimilations from source to sink caused by high temperature. These results show that the damage of future soybean yield and quality is closely related to high temperature stress during seed filling period.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.3
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• pp.21-28
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• 2022

Fine dust enters the lungs or blood vessels through the respiratory tract through the air. Recently, due to the fine dust problem, the demand for air purifiers in Korea is also increasing rapidly. Moss is the oldest terrestrial plant, and it is known that it has the property of adsorbing and decomposing heavy metals and fine dust. To compare the effect of reducing fine dust between moss and the existing chemical filter (Hepa), a cube of 1 m³ was manufactured and the amount of fine dust reduction under a controlled environment was compared. Under the fine dust conditions, an umbrella moss filter, rat tail moss filter, feather moss filter, and silk moss filter were inserted for a total of 40 experiments, 10 times each in 4 different situations. The difference between the amount after 30 minutes was statistically significant for all filters. However, as a result of the test, it was confirmed that there was no statistically significant difference between filters for fine dust, mixed gas, CO₂, and O₂. In particular, it was confirmed that the previously claimed effect of oxygen generation was almost nonexistent. Through this result, it was confirmed that the reduction of fine dust is effective regardless of the species view of moss, and it is expected to replace or supplement the chemical filter of the existing air purifier through future improvement.

• Journal of Cadastre & Land InformatiX
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• v.51 no.2
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• pp.83-106
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• 2021

Interests in clean fuels have been soaring because of environmental problems such as air pollution and global warming. Unlike fossil fuels, hydrogen obtains public attention as a eco-friendly energy source because it releases only water when burned. Various policy efforts have been made to establish a hydrogen based transportation network. The station that supplies hydrogen to hydrogen-powered trucks is essential for building the hydrogen based logistics system. Thus, determining the optimal location of refueling stations is an important topic in the network. Although previous studies have mostly applied optimization based methodologies, this paper adopts machine learning to review spatial attributes of candidate locations in selecting the optimal position of the refueling stations. Machine learning shows outstanding performance in various fields. However, it has not yet applied to an optimal location selection problem of hydrogen refueling stations. Therefore, several machine learning models are applied and compared in performance by setting variables relevant to the location of highway rest areas and random points on a highway. The results show that Random Forest model is superior in terms of F1-score. We believe that this work can be a starting point to utilize machine learning based methods as the preliminary review for the optimal sites of the stations before the optimization applies.

• Journal of Internet Computing and Services
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• v.23 no.1
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• pp.135-145
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• 2022

This paper presented a method to build a predictable smart ammunition logistics system using the 4th industrial technology for ammunition logistics, which is the core functions in the field of defense and logistics. We have analyzed the current level of ammunition logistics with various perspectives such as domestic and overseas logistics policies, technology trends, ammunition logistics characteristics, the smart logistics certification measures by Ministry of Land, Infrastructure and Transport. As a result it is considered that the current ammunition logistics needs needs improvement. To improve this, we presented a direction based on the implications derived after analyzing various ongoing programs such as wired/wireless-based automation, smart ammunition depots, and logistics innovation of the army, navy, and air force that can be applied to the ammunition logistics. In order to implement a data-based smart ammunition logistics management system that can achieve innovation and efficiency of total life cycle while meeting changes in the battlefield environment, we presented 4 objectives such as "automation and modernization of field work", "3D-based storage management & improvement of issuing at war," and "data management for prediction-oriented ammunition management". it is expected that there will be benefits such as improvement of operational continuity, guarantee of ammunition reliability, budget reduction, improvement of inefficiencies such as delay, waiting, and double work, and reduction of accidents.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.113-126
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• 2022

In Small and Medium-sized Enterprises(SMEs) compared to major, competence of CEO relatively has a large impact on management performance, so the biggest factor to strengthen the competitiveness is the competence of CEO. Meanwhile, a consultant is defined as a subject of execution that directly and indirectly participates in management by inducing objective and rational decision-making on various management issues and problems facing companies. The management expertise, problem-solving skills, communication skills, insights, and leadership that a consultant must have in order to perform his or her duties are the same as the role and capabilities that the CEO must have in enhancing the company's performance and competitiveness. Therefore, through previous studies, this study divided consultant competences of CEO into job competence, communication competence, learning competence, and innovation competence and tried to understand whether those competences affect corporate's innovation performance and management performance. The survey was conducted on SMEs and the analysis techniques were reliability and validity analysis, confirmatory factor analysis, and structural equation analysis. As a result, it was found that the CEO's job competence, communication competence, learning competence, and innovation competence had a significant effect on innovation performance of the company, and second, innovation performance had a significant effect on the management performance. Through, this study derived a common factor of consultant competences of SMEs CEO, and derived implications for the competence characteristics of the CEO necessary to improve the performance of SMEs.

• The Korean Journal of Coaching Psychology
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• v.5 no.2
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• pp.25-51
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• 2021

The purpose of this study is to deeply explore the communication process with team members perceived by team leader. To this end, in-depth interviews were conducted with 10 team leaders, and analyzed according to the grounded theory research method procedure suggested by Strauss and Corbin. As a results, a total of 51 concepts, 17 subcategories, and 8 categories were derived. As a causal condition, the concept of 'contemplating and reinterpreting communication necessary for the organization' was derived, and the central phenomenon was 'intentional effort made in parallel with work and private conversations'. The contextual condition was 'recognizing the need to cope with environmental changes', and the mediating condition was 'self-reflection and self-coaching time' was derived. The action/interaction strategy was conceptualized as a communication process with task-oriented coping, conflict resolution coping, and relationship promotion coping, and was confirmed as 'recognizing virtuous cycle communication within the organization' as a result of interaction with the central phenomenon. As a result of analysis of the team leader's communication process, the effort stage, approach stage, coping stage, and cycle stage were shown. As a result of the type analysis, task-oriented coping was a facilitator, conflict resolution coping was a supporter, and relationship promotion coping was a considerate. This study is an empirical study on how the corporate team leader perceives and expresses communication in the relationship with the team members.

• Journal of Science Education
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• v.47 no.1
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• pp.52-62
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• 2023

This study examines how prospective earth science teachers perceive the concept of "equilibrium" and "interaction between Earth's spheres" in understanding Earth's radiative equilibrium and tries to identify their misconceptions. For this purpose, a questionnaire was designed and put to them to look into their thought flow based on the items that appeared in the national level evaluation. As a result of analyzing their answers, even though all the prospective teachers correctly described the concept of radiative equilibrium, about 90% of them did not apply the concept of radiative equilibrium to the new environment of the Earth without atmosphere. They do not seem to be able to smoothly derive the concept of a new 'interaction' between the changed regions and a new 'equilibrium' that will be reached over a long period of time. In this respect, it is likely that the textbooks had some influence on the formation of their concepts. In particular, high school Earth Science textbooks describe the Earth's radiation equilibrium in a quantitative manner, focusing on the heat budget of the equilibrium state rather than the process of reaching radiation equilibrium. Such an approach of textbooks might be an obstacle to fostering students into creative convergence-type talents pursued in the 2015 revised curriculum. Meanwhile, in order to eliminate the misconceptions of students often found in the understanding of Earth's radiation equilibrium, this study suggests that the core concepts need to be dealt with more attention even in college courses for training prospective teachers.