• International journal of advanced smart convergence
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• v.11 no.3
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• pp.142-149
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• 2022

This study aims to develop the education for college students who should perform the social role of the fut ure by conducting trekking activities including the characteristics, history, and culture of Cheonan area and then investigating the sociality and history of 36 college students. Taejosan, Seonggeosan, and Heukseongsan, which are part of the independent ring of Cheonan city, were selected as courses. The training was conducted by six instructors majoring in humanities, history, physical education and medicine. Teachers of humanities and history majors conducted theoretical lectures to raise the historical awareness of Cheonan area related to trekking course. In trekking practice, instructors of physical education and medicine majored in trekking safety education and course progress. Among the social development factors, responsibility, autonomy, and sociality were high. After the education, students recognized that the interest and necessity of history were high in order to understand the present society, thought that they made a lot of development compared to the previous one, and answered that the main development factors of history were the people and that there was a change in perception through this education. This study was composed of the survey after the education, so the psychological characteristics of the individual were not reflected, and it is difficult to generalize it because the number of subjects is small. In the future, more subjects need to be investigated and local residents need to investigate changes in local awareness.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.28-33
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• 2022

A pipe is a hollow, long-form part that is primarily used to transport fluids, such as liquids or gases. Pipes are used in a range of applications in different fields from mechanical purposes to architecture and electrical uses. Despite the significance owing to various usability of pipes, few studies have been conducted using the physical property test method. The tensile test is widely used as a method to check the physical properties of the pipe. The existing pipe tension test contains the possibility to cause errors, which are fractures outside the gauge distance and cross-sectional deformation of the pipe. In this study, a novel pipe tension test method using a jig is presented and pipes with various materials are tested. It is expected that the proposed method can reduce errors that occur in conventional pipes and also obtain more accurate values to enable more efficient testing.

• ETRI Journal
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• v.45 no.2
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• pp.346-357
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• 2023

Hardware security primitives, also known as physical unclonable functions (PUFs), perform innovative roles to extract the randomness unique to specific hardware. This paper proposes a novel hardware security primitive using a commercial off-the-shelf flash memory chip that is an intrinsic part of most commercial Internet of Things (IoT) devices. First, we define a hardware security source model to describe a hardware-based fixed random bit generator for use in security applications, such as cryptographic key generation. Then, we propose a hardware security primitive with flash memory by exploiting the variability of tunneling electrons in the floating gate. In accordance with the requirements for robustness against the environment, timing variations, and random errors, we developed an adaptive extraction algorithm for the flash PUF. Experimental results show that the proposed flash PUF successfully generates a fixed random response, where the uniqueness is 49.1%, steadiness is 3.8%, uniformity is 50.2%, and min-entropy per bit is 0.87. Thus, our approach can be applied to security applications with reliability and satisfy high-entropy requirements, such as cryptographic key generation for IoT devices.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.75-76
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• 2020

Use fire resistant construction methods, of which fire resistant boards are used to protect buildings and structures from fire. However, in the case of fire resistant boards, the unit price of the main raw material is high and the cost efficiency is low. There have been studies to apply oyster shells to fire resistant boards to solve these problems. On the other hand, egg shells are also considered to be applicable to fire-resistant boards with components like oyster shells, but there is no case of using egg shells as building materials. Therefore, in this study, we confirmed the physical properties of egg shell powers used as mortar filler and compared them with the fire resistant board flexural strength standard. As a result, it was judged that the powder of egg shells could be used as a building material, because the standards for the flexural strength of fire resistant boards were satisfied except for a part.

• Advances in nano research
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• v.15 no.4
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• pp.329-337
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• 2023

Wearing the right sportswear is one of the essential points in exercising, which is mainly neglected. Sportswear should be suitable for the ambient temperature and not cause more heat or cold in the athlete's body. On the other hand, increased sweating and blood circulation during exercise should not cause fatigue or heatstroke in the athlete. Nanotechnology has grown significantly in the field of producing more efficient equipment in the field of sports. The increase in demand in sports for complete sports equipment has revealed the necessity of using the highest quality materials in this sector. In the world of championship sports, a minor change in equipment can lead to significant changes in causing failure and victory. Since the sole is the most critical part of sports shoes, with the introduction of nanotechnology and nanocomposites, it is possible to help athletes rush and increase their sense of calm and satisfaction. Using nanocomposites in the soles of shoes can improve some of their characteristics, prevent the smell and sweat of shoes, and induce water repellency in these shoes. In this research, titanium dioxide (TiO₂) nanocomposite, along with cellulose, has been used to create antibacterial and hydrophobic properties in the soles of sports shoes. The synthesized nanocomposite has been synthesized using the least amount of chemicals, which shows this method's easy and cost-effective synthesis.

• Journal of Conservation Science
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• v.5 no.1 s.5
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• pp.20-40
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• 1996

For obtaining the basic data for establishing plan on the conservation of the Gameunsa 3-story and Naweonri 5-story Pagodas located at the Kyeongju city, the characteristics of the rock and weathering phenomena have been investigated. The former consists of quartz-rlch granite containing small amount of biotite, and the latter of alkali granite with abundant perthite, These rock phases are nearly identical to the marginal phase of medium-grained hornblende-biotite granodiorite and alkali granite respectively, which are distributed around the Kyeongju city. The rock weathering may be governed mainly by chemical weathering of feldspar following physical segregation of quartz grains and pervasive moss. The feldspar easily dissolve In the solution with pH<7 to precipitate clay mineral such as a kaolinite as a secondary phase on the feldspar surface. However, the chemical weathering of feldspar may continue when the surface is washed by the rain according to removal of the reprecipitated phase. On forwarding, the weathering may be greatly Influenced by the acid rain. Exfoliation and weathering along igneous lineation resulting in exfoliating along the structural line are the characteristic weathering phenomena. Also the secondary small cracks are irregularly developed on the rocks due to different strain on places by the overall structural unbalance of the pagodas. Along these cracks, the rain water intrudes deeply into the rocks and weathering occurs intensively compared to other parts. Weathering may be artificially promoted by the grinding or sculpturing when the pagodas were made. Because it may influence on the physical properties of the rocks as well as destruct the surface of the feldspar crystals, the major constituents of the rocks, it results in providing the environment of easy chemical weathering along time. For conservation, the pagodas must be structurally balanced by compacting the soil basement and supplementing rocks on the destroyed part. On the exfoliated part it is better not to be artifically treated as using cementing material. But the cracks may be filled up by cementing material to avoid the intrusion of acidic water. To supplement the rocks on the destroyed part, it may be better to use similar rock phases from identical biotite granite and alkali granite masses around the Kyeongju city.

• Korean Journal of Hospice Care
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• v.5 no.1
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• pp.14-25
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• 2005

This study was conducted to examine the present state, types of services, difficulties, education programs, motivation, satisfaction and attitude of hospice volunteers and also to suggest supporting programs for the volunteer. For these purposes, a questionnaire was distributed among the 200 hospice volunteers in ten hospice organizations in Daejeon and Chungcheong province. In this research, 85.5% of the respondents were women and most of them were housewives in their forties and fifties. The majority of hospice volunteers had an education background of more than high school. Christianity (94%) was the dominant religion of volunteers. Among the service area of the hospice, emotional caring, such as listening closely and establishing empathy were the most frequently done by the respondents and the next one was spiritual care. Hospice volunteers who had started with altruistic motivation show more dynamic activities in emotional, spiritual, physical caring and so on, than those with non-altruistic motivation. Most of the respondents expressed that they felt a hospice volunteer was valuable. However they had a hard time to overcome the sorrow coming from sharing empathy with the dying patients. Those who had started with altruistic motivation usually took part in two times per a week and had more positive attitude. Volunteers who had been working more than five years showed better attitude than those who had been working less than three years. The longer the voluntary services, the more positive attitude experienced by volunteers. Hospice volunteers encountered the most considerable difficulty with lack of background knowledge and their actual capability. Insufficiency of time was the next reason for the considerable difficulty of the hospice volunteer. On the other hand, those who served more than twice per week replied that lack of background knowledge and their capability were the least considerable difficulty. Insufficiency of time was the reason of difficulty for male volunteers, as well as for females under thirty and those in their forties and fifties respectively. Generally most of the hospice volunteers (70%) were satisfied with their services and they usually satisfied with physical caring, spiritual caring, hospice's family caring. The less difficulty in voluntary services, more satisfaction for the volunteers in the end. There is a positive correlation between a attitude of the hospice volunteer and frequency of voluntary services while the volunteers' difficulty affect negatively their attitude as well as the frequency of voluntary services. Most of the hospice volunteers want to have more education about basic skills, volunteer's attitude and role, spirituality, the way of attending on the hospice and so on. Most of them considered discussion and sharing different cases as the most effective method. They also wish to had more supporting programs for the hospice volunteers(in the order of their needs) such as regular events, newsletters, personal concern, social meetings among the volunteers, insurance and minimum expenses. Based on the study results, more programs should be run in order to activate the voluntary services regardless of their gender and education background. A continuous practical supporting policy and education programs are required in order to provide special education and training courses considering every field of voluntary services. Expanding the role of the volunteers allows them more opportunities to take part in voluntary services and th activate participation. It is necessary to establish a new hospice system as a part public medical system, which can not only facilitate the voluntary services for a hospice but also enhance professional hospice volunteers. Finally, experts are needed to operate the voluntary services effectively.

• 한국체육학회지인문사회과학편
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• v.55 no.2
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• pp.35-46
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• 2016

This study aims to observe the operation aspect of physical education during before class and further, to search for the utmost improvement direction using IPA (Importance-Performance Analysis). 500 middle & high school students have chosen through a purposeful sampling method, and 430 was used for analysis. The results were as follows. The quadrant I is "the keep up the good work" part. And the quadrant I includes "de-stress", "the pleasure of school life", "improvement in performance", "peer relationship", "help for P.E.", "health promotion", "sport facility surroundings", "rules", "teacher leadership", "passionate coaching", "fair coaching", "improvement in exercise ability", "understanding P.E." The quadrant II is "the concentrate here" part. And the quadrant II includes "develop talent", "excercise time", "safety management for exercise facility", "new sports event", "consider needs and interests", "consider level" "consider gender". The quadrant III is "the low priority" part. And the quadrant III includes "change of personality", "ability to do various sports event", "develope thinking ability". "communication with peer" "an intelligible explanation" In order to improve the quality of before classes, first, "safety connected program" second, "emotional and intellectual development program", third, "divided classes per level and gender", and the last, "professional manpower for developing the quality of class" are needed.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4447-4464
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• 2023

This paper focuses on the development of a new computational model of the CNESTEN's TRIGA Mark II research reactor using the 3D continuous energy Monte-Carlo code TRIPOLI-4 (T4). This new model was developed to assess neutronic simulations and determine quantities of interest such as kinetic parameters of the reactor, control rods worth, power peaking factors and neutron flux distributions. This model is also a key tool used to accurately design new experiments in the TRIGA reactor, to analyze these experiments and to carry out sensitivity and uncertainty studies. The geometry and materials data, as part of the MCNP reference model, were used to build the T4 model. In this regard, the differences between the two models are mainly due to mathematical approaches of both codes. Indeed, the study presented in this article is divided into two parts: the first part deals with the development and the validation of the T4 model. The results obtained with the T4 model were compared to the existing MCNP reference model and to the experimental results from the Final Safety Analysis Report (FSAR). Different core configurations were investigated via simulations to test the computational model reliability in predicting the physical parameters of the reactor. As a fairly good agreement among the results was deduced, it seems reasonable to assume that the T4 model can accurately reproduce the MCNP calculated values. The second part of this study is devoted to the sensitivity and uncertainty (S/U) studies that were carried out to quantify the nuclear data uncertainty in the multiplication factor k_eff. For that purpose, the T4 model was used to calculate the sensitivity profiles of the k_eff to the nuclear data. The integrated-sensitivities were compared to the results obtained from the previous works that were carried out with MCNP and SCALE-6.2 simulation tools and differences of less than 5% were obtained for most of these quantities except for the C-graphite sensitivities. Moreover, the nuclear data uncertainties in the k_eff were derived using the COMAC-V2.1 covariance matrices library and the calculated sensitivities. The results have shown that the total nuclear data uncertainty in the k_eff is around 585 pcm using the COMAC-V2.1. This study also demonstrates that the contribution of zirconium isotopes to the nuclear data uncertainty in the k_eff is not negligible and should be taken into account when performing S/U analysis.

• Journal of the Ergonomics Society of Korea
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• v.33 no.4
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• pp.281-287
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• 2014

Objective: The objective of the study is to develop a portable assistance device to help elderly users reduce strain on the knee and leg muscle while the elderly are standing up. Background: The pose of standing up from a chair is a basic movement, but the elderly often have difficulty standing up due to their weak muscles. We focus on designing a solution that helps the elderly reduce physical problems and support them standing up. Method: This study consists of three parts. Part I explores the way to reduce the refrain of leg muscle while standing up from a chair. In the process of structural development, we found that the moment is minimized when user pushes down the armrests due to a decrease in the force acting on the center of mass. In part II, a user test of 20 participants was carried out to rank the order of comfort of two stimuli: the chair with fixed armrests and the chair with the four-link mechanism that we created-in three different ways; (1) to stand up without touching armrests, (2) to stand up by pushing down on fixed armrests, and (3) to stand up by pushing down on armrests and being supported by the mechanism. To examine the statistically significant differences among the rank means, a Friedman test was conducted. In part III, we analyze the results of the user test and interview feedbacks, focusing on establishing a design strategy from UPO and visualizing it in 1:1 scale. Results: In part I, we decided to develop the four-link mechanism. The bottom is lifted up as the link rises. In part II, based on the rank data, we empirically found that UPO was assessed as the most comfortable during the stimuli. The thigh angle is smaller and the bottom of UPO is separated from a seat. In part III, after assessing the results and feedbacks, we created a visualization strategy for UPO: light, friendly, and novel. Conclusion: The portable and non-mechanical UPO comprises a four-link system that lifts the user's hips while standing. It can help users avoid knee and leg muscle strain. Its universal design considers the elderly's difficulties. Application: In a future study, combining light and durable material in UPO is expected to increase its usability. And this study is an opportunity to design various types of standing assistance devices.