• Transactions of Materials Processing
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• v.32 no.3
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• pp.153-159
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• 2023

This paper presents the optimal design of a heating system using radiant heating elements for application in smart farms. Smart farming, an advanced agricultural technology, is based on artificial intelligence and the internet of things and promotes crop production. Temperature and humidity regulation is critical in smart farms, and thus, a heating system is essential. Radiant heating elements are devices that generate heat using electrical energy. Among other applications, radiant heating elements are used for environmental control and heating in smart farm greenhouses. The performance of these elements is directly related to their electrical energy consumption. Therefore, achieving a balance between efficient electrical energy consumption and maximum heating performance in smart farms is crucial for the optimal design of radiant heating elements. In this study, the size, electrical energy supply, heat generation efficiency, and heating performance of radiant heating elements used in these heating systems were investigated. The effects of the size and electrical energy supply of radiant heating elements on the heating performance were experimentally analyzed. As the radiant heating element size increased, the heat generation efficiency improved, but the electrical energy consumption also increased. In addition, increasing the electrical energy supply improved both the heat generation efficiency and heating performance of the radiant heating elements. Based on these results, a method for determining the optimal size and electrical energy supply of radiant heating elements was proposed, and it reduced the electrical energy consumption while maintaining an appropriate heating performance in smart farms. These research findings are expected to contribute to energy conservation and performance improvement in smart farming.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.345-353
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• 2009

The success and failure of any project depends upon many factors, the Project Manager is considered to be the key contributor to the success of any project, as well as a guide to the team members to achieve the client satisfaction (Cost, Time and Quality). Therefore the main aim of this paper is to provide a practical approach for understanding the importance of the Project Manager and his effectiveness to the success of the construction projects. In addition, the Project Manager's roles, responsibilities and duties have direct impact to the success of the construction projects. In order to identify the thoughts and opinion of the construction industry on this particular assertion, a quantitative study was carried out within the UK construction industry. The result of the study shows that there is an extremely strong correlation between the Project Manager and the success of the construction projects. In construction projects the Project Manager is considered to be one of the most important people who can lead and drive the projects in the right direction and conclude construction projects successfully. Moreover, these can play the most important role regarding the improvement of the organization's performance, the organization's profitability and the client's satisfaction. The research confirmed that the Project Manager is a very essential element to the success of the construction project and have an impact at every stage of the construction project. So it concluded that selection of a Project Manager should be carefully done with regard to experience, knowledge, power/authority and good understanding to the kind of the project.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.195-204
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• 2023

Purpose : This study applied general training (control group) or cranio-cervical flexor training (experimental group) using a pressure biofeedback unit along with general training for 4 weeks to secondary school teachers with moderate to severe neck pain and forward head posture. After that, we tried to compare the effects through differences in neck pain intensity (using numberical rating scale), functional performance (using neck disability index), and cranio-vertebral angle change. Methods : All 50 subjects were randomly assigned to either the "experimental group (n= 25)" or the "control group (n= 25)", and the measurements were evaluated in the same way before the intervention (baseline) and after the intervention (4 weeks). During the intervention period, the subject visited the physiotherapy center and made a reservation three times a week at a fixed time as much as possible, and each training session was thoroughly conducted under the 1:1 guidance of the therapist in charge so that the correct movement and number of times could be performed without compensatory action. Results : As a result of the homogeneity analysis on the general characteristics of the subjects, there were no significant differences between the groups in all variables (p>.05). Compared to the "control group", the "experimental group" showed significant improvement after intervention in all measured variables of neck pain intensity, functional performance, and cranial-vertebral angle (p<.05). Conclusion : For secondary school teachers with forward head accompanied by neck pain, cranio-cervical flexor training using a compression biofeedback unit is an excellent method to show superior pain reduction and functional performance improvement compared to general training alone. In addition, it can be presented as a more effective intervention method that can promote recovery of forward head posture, which is an essential element of the solution.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.2
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• pp.323-336
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• 2023

In the 21st century, fashion films are frequently used throughout the fashion industry. In particular, as videos have become an essential element and a communication tool of social media, they are becoming even more important in the world of fashion. In this study, different types of short-length fashion films (< 0:60) in current use were derived, and the effects of on the cognitive and emotional responses of users were analyzed using electroencephalogram(EEG) findings. EEG measurements were performed using Epoc+ on 31 healthy women aged 20-29 years after viewing six types of fashion films[fiction/well-made, fiction/user generated content(UGC), documentary/well-made, documentary/UGC, art/well-made, and art/UGC] in random order. The results demonstrate differences among four types of films. Specifically, alpha waves in the frontal lobe decreased more while watching documentary/UGC films than while watching art/well-made films. Gamma waves in the temporal lobe decreased more while watching fiction/well-made films than while watching documentary/UGC films. Furthermore, theta waves in the occipital lobe increased more while watching fiction/well-made films than while watching art/UGC films. These findings suggest that different types of fashion films can stimulate different parts of the brain that process thinking, cognition, emotion, and visual and auditory information and consequently evoke emotional responses.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1382-1399
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• 2023

Pressure relief valve (PRV) is one of the important control valves used in nuclear power plants, and its sealing performance is crucial to ensure the safety and function of the entire pressure system. For the sealing performance improving purpose, an explicit function that accounts for all design parameters and can accurately describe the relationship between the multi-design parameters and the seal performance is essential, which is also the challenge of the valve seal design and/or optimization work. On this basis, a surrogate model-based design optimization is carried out in this paper. To obtain the basic data required by the surrogate model, both the Finite Element Model (FEM) and the Computational Fluid Dynamics (CFD) based numerical models were successively established, and thereby both the contact stresses of valve static sealing and dynamic impact (between valve disk and nozzle) could be predicted. With these basic data, the polynomial chaos expansion (PCE) surrogate model which can not only be used for inputs-outputs relationship construction, but also produce the sensitivity of different design parameters were developed. Based on the PCE surrogate model, a new design scheme was obtained after optimization, in which the valve sealing stress is increased by 24.42% while keeping the maximum impact stress lower than 90% of the material allowable stress. The result confirms the ability and feasibility of the method proposed in this paper, and should also be suitable for performance design optimizations of control valves with similar structures.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.134-134
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• 2019

Utilization of organic waste as a renewable energy source is promising for sustainability and mitigation of climate change. Pyrolysis converts organic waste to gas, oil, and biochar by incomplete biomass combustion. Biochar is widely used as a soil conditioner and adsorbent. Biochar adsorbs/desorbs metals and ions depending on the soil environment and condition to act as a nutrient buffer in soils. Biochar is also regarded as a carbon storage by fixation of organic carbon. Phosphorus (P) and nitrogen (N) are strictly controlled in many wastewater treatment plants because it causes eutrophication in water bodies. P and N is removed by biological and chemical methods in wastewater treatment plants and transferred to sludge for disposal. On the other hand, P is an irreplaceable essential element for all living organisms and its resource (phosphate rock) is estimated about 100 years of economical mining. Therefore, P and N recovery from waste and wastewater is a critical issue for sustainable human society. For the purpose, intensive researches have been carried out to remove and recover P and N from waste and wastewater. Previous studies have shown that biochars can adsorb and desorbed phosphates implying that biochars could be a complementary fertilizer. However, most of the conventional biochar have limited capacity to adsorb phosphates and nitrate. Recent studies have focused on biochar impregnated with metal salts to improve phosphates and nitrate adsorption by synthesizing biochars with novel structures and surface properties. Metal salts and metal oxides have been used for the surface modification of biochars. If P removal is the only concern, P adsorption kinetics and capacity are the only important factors. If both of P and N removal and the application of recovery are concerned, however, P and N desorption characteristics and bioavailability are also critical factors to be considered. Most of the researches on impregnated biochars have focused on P removal efficiency and kinetics. In this study, coffee waste is thermally treated to produce biochar and it was impregnated with Mg/Al to enhance phosphates and nitrate adsorption/desorption and P bioavailability to increase its value as a fertilizer. Kinetics of phosphates and nitrate adsorption/desorption and bioavailability analysis were carried out to estimate its potential as a P and N removal adsorbent in wasewater and a fertilizer in soil.

• Convergence Security Journal
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• v.22 no.4
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• pp.109-118
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• 2022

Countries around the world have recognized the importance of personal information protection and have discussed protecting the rights of data subjects in various forms such as laws, regulations, and guidelines. PbD (Privacy by Design) is one of the concepts that are commonly emphasized as a precautionary measure for the protection of personal information, and it is starting to attract attention as an essential element for protecting the privacy of information subjects. However, the concept of PbD to prioritize individual privacy in system development or service operation in advance is still only at the declarative level, so there is relatively little discussion on specific methods to implement it. Therefore, this study discusses which principles and rights should be prioritized to implement PbD based on the basic principles of GDPR and the rights of data subjects. This study is meaningful in that it suggests a plan for the practical implementation of PbD by presenting the privacy considerations that should be prioritized when developing systems or services in the domestic environment.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.349-377
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• 2023

With the recent advancements in artificial intelligence, the emergence of ChatGPT is expected to bring significant changes to various industries. In particular, there are active attempts to introduce ChatGPT in the education sector, and for librarians, utilizing ChatGPT is seen as an essential element for future learning tools. Against this background, this study aimed to examine librarians' perceptions of introducing ChatGPT in the school library through Focus Group Interviews (FGI). As a result, six themes were derived, including differences in perceptions of ChatGPT application in school libraries, teaching and learning activities utilizing ChatGPT, practical operation of ChatGPT, considerations for successful performance, librarians' required competencies and environment (infrastructure), and the development direction of ChatGPT utilization services in school libraries. Based on these findings, implications for the necessity of educational services utilizing ChatGPT were proposed. This study is significant as the first attempt to introduce ChatGPT in the school library field.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.335-343
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• 2019

Healthy living is an essential element of human happiness. Quality eating provides the basis for life, and the health of livestock, which provides meat and dairy products, has a direct impact on human health. In the case of calves, diarrhea is the cause of all diseases.In this paper, we use a sensor to measure calf 's biometric data to diagnose calf diarrhea. The collected biometric data is subjected to a preprocessing process for use as meaningful information. We measure calf birth history and calf biometrics. The ontology is constructed by inputting environmental information of housing and biochemistry, immunity, and measurement information of human body for disease management. We will build a knowledge base for predicting calf diarrhea by predicting calf diarrhea through logical reasoning. Predict diarrhea with the knowledge base on the name of the disease, cause, timing and symptoms of livestock diseases. These knowledge bases can be expressed as domain ontologies for parent ontology and prediction, and as a result, treatment and prevention methods can be suggested.

• Geomechanics and Engineering
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• v.31 no.3
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• pp.249-263
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• 2022

The specially-shaped Polycrystalline Diamond Compact (PDC) cutter is widely used in drill bit design due to its advantages of high rock cutting efficiency, strong impact resistance and long service life in hard and abrasive formation drilling. A detailed understanding of rock cutting behavior of worn specially-shaped PDC cutter is essential to improve the drilling efficiency and decrease the drilling costs. In this paper, the theoretical models of two new principles (loading performance (LP) and cutting performance (CP)) are derived for evaluating the cutting process of worn specially-shaped cutter, the theoretical models consider the factors, such as cutter geometry, aggressiveness, stress state, working life, and rock cutting efficiency. Besides, the numerical model of heterogeneous granite is developed using finite element method combined with Voronoi tessellation, the LP and CP of 12 kinds of worn specially-shaped PDC (SPDC) cutters are analyzed. The results found that the mechanical specific energy (MSE) of worn cutters first increase and then decrease with increasing the cutting depth, and the MSE increase with the increase of back rake angle except for Conical cutter and Wedge-shaped cutter. From the perspective of CP, the worn PDC cutters are more suitable for the smaller cutting depths, and the back rake angle has little effect on the CP of the specially-shaped worn PDC cutters. Conical cutter, Saddle-shaped cutter and Ellipse-shaped cutter have the highest CP value, while Rhombus-shaped cutter, Convex cutter and Wedge-shaped cutter have the lowest value in selecting cutters. This research leads to an enhanced understanding of rock-breaking mechanisms of worn SPDC cutters, and provides the basis to select of specially-shaped PDC cutters for the specific target formation.