• Title/Summary/Keyword: core strength

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A Study on Job Analysis and Physical Fitness of Special Security Guard in Nuclear Power Plant (원자력발전소 특수경비원의 직무분석과 체력에 관한 연구)

  • Jeong, Howon;Kim, Sora;Chae, Hyeonsoo
    • Korean Security Journal
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    • no.56
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    • pp.83-105
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    • 2018
  • Special security guards play the role to safely operate and manage nuclear power plants from unintended internal and external threats. Physical fitness management of special security guards is one of the most important factors for improving and maintaining the level of physical protection. Thus, the purpose of this study is to analyze the physical fitness factor and physical fitness level required for mission accomplishment through job analysis of special security guards. The special security guards of Nuclear Power Plant in Korea were performing 7 jobs, 26 duties, 159 tasks. In order to accomplish theses tasks, the following physical fitness were required: muscle strength and muscle endurance of the hand, upper limb, lower limb and core, quickness, agility and Cardio function. The duties that require a lot of physical fitness were in the order of conducting arrest and self-defense, conducting unarmed defensive tactics, demonstrating proficiency with semiautomatic rifle, using protective equipment, performing emergency plan and defensive strategy, etc. The results of this study are expected to provide basic data necessary for establishing guidelines for fitness qualification and training of special security guards in the future and contribute to enhancement of physical protection of nuclear power plants.

Surface Milling for the Study of Pore Structure in Shale Reservoirs (셰일 저류층 내 공극 구조 연구를 위한 표면 밀링)

  • Park, Sun Young;Choi, Jiyoung;Lee, Hyun Suk
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.4
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    • pp.419-426
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    • 2020
  • Understanding the pore structure including pore shape and connectivity in unconventional reservoirs is essential to increase the recovery rate of unconventional energy resources such as shale gas and oil. In this study, we found analysis condition to probe the nanoscale pore structure in shale reservoirs using Focused Ion Beam (FIB) and Ion Milling System (IMS). A-068 core samples from Liard Basin are used to probe the pore structure in shale reservoirs. The pore structure is analyzed with different pretreatment methods and analysis condition because each sample has different characteristics. The results show that surface milling by FIB is effective to obtain pore images of several micrometers local area while milling a large-area by IMS is efficient to observe various pore structure in a short time. Especially, it was confirmed that the pore structure of rocks with high content of carbonate minerals and high strength can be observed with milling by IMS. In this study, the analysis condition and process for observing the pore structure in the shale reservoirs is established. Further studies are needed to perform for probing the effect of pore size and shape on the enhancement of shale gas recovery.

Effects of EMS Compression Belts with Different Muscular Patterns on Lumbar Stabilization (근육모양의 패턴을 달리한 EMS 복압벨트가 요추 안정화에 미치는 영향에 관한 연구)

  • Kim, Dae-Yeon;Park, Jin-hee;Kim, Joo-Yong
    • Science of Emotion and Sensibility
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    • v.24 no.2
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    • pp.81-92
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    • 2021
  • In this study, we investigated the effects of five EMS lumbar back pressure belts produced on an anatomical basis on lumbar spine stabilization. Five core muscles were selected, including the urinal, vertebral column, endotracheal, external abdominal, and large back muscles, and patterns were designed using a conductive fabric considering the appropriate muscle shape and pain-causing points. We experimented with four motions to examine the effects of different EMS abdominal compression belts on lumbar spine stabilization. Five healthy men in their 20s were selected. The selection conditions include no back pain history for the past three months, no restricted movements through pre-inspection, and the muscular strength of the body should belong to the normal grade. Using SLR, the sequence of experimental actions was chosen from the following but not limited to left-hand, body-hand, and back-line forces. Resting between movements lasted for 2 min, and the experiments were conducted after wearing the EMS abdominal pressure belt. Electrical stimulation was applied for 10 min to increase blood flow and muscle activation. The statistics of the experimental results were analyzed for specific differences by conducting the Wilcoxon and Friedman tests with nonparametric tests. The ranking results of each pattern were successfully assessed in the order of 5, 4, 3, 1, 2 for the five patterns, and we could identify slightly more significant results for experimental behavior associated with each muscle movement. Patterns produced based on anatomy showed differentiated effects when electric stimulation was applied to each muscle in different shapes, which could improve the stabilization of the lumbar spine in everyday life or training to the public. Based on these results, subsequent research would focus on developing smart healthcare clothing that is practical in daily life by employing different anatomical mechanisms, depending on the back pain, to utilize trunk-type tights.

Load-Displacement Relationship of Passive Vibration Units Composed with a Spring and Vibration-Proof Rubbers (스프링과 방진고무가 융합된 제진장치의 하중-변위 관계)

  • Mun, Ju-Hyun;Im, Chae-Rim;Wang, Hye-Rin;Yang, Keun-Hyeok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.226-234
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    • 2021
  • The objective of this study is to establish the fundamental design data for axial load-displacement relationship under axial monotonic or cyclic responses of seismic damping·isolation (SDI) units developed for ceiling structures. The main parameters include the installation of a spring, the number of rubber layer, prestress stress of bolts for connector between the spring and rubbers, and loading type. Test results showed that SDI units with a spring in the core and higher prestress stress of bolts tended to be higher stiffness at the ascending branch and more ductile behavior at the descending branch. This trends more notable for the specimens under monotonic load rather than cyclic loads. Consequently, the energy dissipation of SDI unit can be optimally designed with the following conditions: installation of a spring within 3-layer rubbers and prestress applied to the bolts at 10% of their yielding strength . When compared with the experimental tension capacity of the developed SDI units, the predictions by JIS B 2704-1 and KDS 31 00 are conservative under monotonic loading but higher by approximately 10% under cyclic loading.

A Study on the Vibration Analysis of Spindle Housing with High Strength Aluminum of 2NC Head in Five-axis Cutting Machine Training (5축 절삭가공기 교육 중 2NC 헤드의 고강도 알루미늄을 적용한 스핀들 하우징의 극한 조건의 진동해석에 관한 연구)

  • Lee, Ji Woong
    • Journal of Practical Engineering Education
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    • v.14 no.1
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    • pp.119-125
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    • 2022
  • Materials used for education are materials such as SM20C, Al6061, and acrylic. SM20C materials are carbon steel and are often used in certification tests and functional competitions, but are also widely used in industrial sites. The Al6061 material is said to be a material that has lower hardness and stronger flexibility than carbon steel, so it is a material that generates a lot of compositional selection of tools. If students are taught practical training using acrylic materials, vibration occurs due to excessive cutting in some parts and damage to the tool occurs. In this process, we examine to what extent the impact on the 2NC head, which is a five-axis equipment, can affect precision control. The weakest part of the five-axis equipment can be said to be the weakest part of the head that controls the AC axis. When the accuracy and cumulative tolerance of this part occur, the accuracy of all products decreases. Therefore, the core part of the 2NC head, the spindle housing, was carried out using an Al7075 T6 (Alcoa, USA) material. In the process of vibration and cutting applied to this material, the analysis was conducted to find out the value applied to the finite element analysis under extreme conditions. It is hoped that this analysis data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

Bibliometric Analysis of Herbal Medicine on Atopic Treatment Research Trends over the Past 20 Years (최근 20년간 한약을 중심으로 한 아토피 질환 치료에 대한 계량서지학적 분석)

  • Hye-Jin Park;Hyoen-Jun Cheon;So-Eun Son;So-Mi Jung;Jeong-Hwa Choi;Soo-Yeon Park;Min-Yeong Jung;Jong-Han Kim
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.36 no.2
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    • pp.60-75
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    • 2023
  • Objectives : A bibliometric approach using network analysis was applied to explore the global trends of research on herbal medicine for atopic treatment. Methods : Articles related to herbal medicine on atopic treatment from 2003 to 2022 were retrieved from Web of Science Core Collection. Extracted records were analyzed according to the publication year, research area, journal title, country, organization, author and keyword. The VOSviewer program was used to visualize the trends and the research hotspots in herbal medicine for atopy. Results : Analysis of 406 articles indicated the consistent increase of using herbal medicine for atopic treatment over the last 20 years. The most productive country and research organization in issuing articles were South Korea and Kyunghee university. Many articles have been published in research areas such as 'integrative complementary medicine' and 'pharmacology pharmacy'. By evaluating the total link strength, the average publication year and the average citations of countries and authors, the influential countries and authors were identified. A network analysis based on the co-occurrence and the publication year of keywords revealed the relevant characteristics and trends of herbal medicine for atopy. The most up-to-date keywords were 'topical application', 'skin barrier' and 'care'. Conclusions : This bibliometric study examined the overall trends and the time-based development of herbal medicine for atopic treatment. The current study would be useful not only for grasping the global network hub of research on herbal medicine for atopic treatment, but also to explore the new directions for future research.

Geotechnical Engineering Characteristics of Ulleung Basin Sediment, East Sea (동해, 울릉 분지 심해토의 지반공학특성)

  • Lee, Chang-Ho;Yun, Tae-Sup;J.C., Santamarina;Bahk, Jang-Jun;Lee, Jong-Sub
    • Journal of the Korean Geotechnical Society
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    • v.25 no.6
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    • pp.17-29
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    • 2009
  • There has been an increase in the investigation of deep sea sediments with a consequent increase in the amount of energy required to undertake these investigations. The geotechnical characteristics of Ulleung Basin sediment are explored by using depressurized specimens following methane production tests carried out on pressured core samples obtained at 2,100 m water depth and 110 m below sea floor. Geotechnical index tests, X-ray diffraction, and scanning electron microscope are conducted to identify the geotechnical index parameters, clay mineralogy, chemical composition, and microstructure of the sediments. Compressibility, and elastic and electromagnetic wave parameters are investigated for two samples by using a multi sensing instrumented oedometer cell. The strength chatracteristics are obtained by the direct shear tests. The dominant clay minerals are mostly kaolinite, illite, chlorite, and calcite. The SEM shows a well-developed flocculated structure of the microfossil. Void ratio, electrical resistivity, real permittivity, conductivity, and shear wave velocity show bi-linear behavior with the effective vertical stress: as the vertical effective stress increases. The friction angle obtained by the direct shear test is about $21^{\circ}$, which is similar to the value observed in the Ulleung Basin sediments. This study shows that the understanding of the behavior acting on the diatomaceous marine sediment is important because it often maintains the useful energy resources such as gas hydrate and so will be the new engineering field in the next generation.

A Study on Factors Affecting the Sustainability of Industry-University Cooperation: Focusing on the I-U Relationship Strength and Overcoming I-U barrier (산학협력 지속가능성에 영향을 주는 요인에 관한 연구: 산학협력관계강도와 장애의 극복을 중심으로)

  • Hong, Eun-Young;Choi, Jong-in
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.410-422
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    • 2018
  • This paper studies the factors that increase the sustainability of Industry-University cooperation in the current structure of domestic I-U cooperation, which is highly dependent on government support. First, we examine the extent to which the 'I-U Relationship Strength' can be explained by the cumulative 'Experiences of I-U cooperation' and 'Width of various I-U cooperation channels', and the 'I-U cooperation barrier' can be explained by the 'Difference in mutual recognition' and 'Institutional barriers' on sustainability. In addition, the factors that can lower the 'I-U cooperation barrier', such as the 'University administration's efforts' and 'Trust between I-U', are examined. The researchers examined the factors affecting the sustainability of I-U cooperation and the factors affecting 'I-U cooperation barriers' in the 'I-U cooperation technology development projects' of the Ministry of Small & Medium Venture Business and Startups with its long history of domestic I-U cooperation programs. In order to clarify the data of the research sample, a questionnaire survey of organizational units was conducted for all companies participating in the 'I-U cooperation technology development projects' of the Ministry of SMVB and Startups between 2011 and 2015, and the responses of 356 organizations were used. It was found that the greater the 'Width of the I-U cooperation channels', the higher the sustainability and that the greater the 'Institutional barriers', the lower the sustainability. However, through the 'University administration's efforts' and 'Trust between I-U', it is possible to overcome the 'I-U cooperation barrier'. Ultimately, the systematization of Industry-University-Research institute subjects is needed to realize sustainability. In other words, it is necessary to have a linkage program that can broaden the link between industry and universities, that is to broaden the scope of I-U cooperation. Moreover, it is necessary for the government to provide institutional support to promote desirable I-U cooperation policies. Finally, it is essential to change the universities' core organizations in order to improve the level of university administration services.

Influence of Soil Texture and Bulk Density on Root Growth Characteristics and Nutrient Influx Rate of Soybean Plant (토성(土性)과 용적밀도(容積密度)가 대두(大豆)의 뿌리 생장특성(生長特性)과 양분흡수기능(養分吸收機能)에 미치는 영향(影響))

  • Jung, Yeong-Sang;Lim, Hyung-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.3
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    • pp.221-227
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    • 1989
  • This study was conducted to understand the influence of soil compaction on root growth and nutrient uptake characteristics of the soybean roots grown in two soils with different texture. Tap root elongation was measured on young seedling grown in cores compacted to different bulk densities of 1.2, 1.4 and $1.6/cm^3$ with different soil water retention in laboratory. The soil used were Samgag sandy loam and Baegsan loam soils. The wet and dry weight, total length, average radius and total surface area of roots were measured on soybean plants grown in 1/5000 a Wagner pots compacted to different bulk density of 1.2 and $1.4g/cm^3$. The nutrient uptake of soybean shoot was measured and evaluated with the unit surface area of roots at the 7th, 17th and 27th days after germination. The results were as follows: 1. The tap root elongation rate was faster in the loam soil with low bulk density than in the sandy loam soil with high bulk density. The elongation rates were remarkedly decreased when soil water was lower than the retention of 4 bars in loam soil and that of 1 bars in sandy loam soil. 2. Tap root elongation rate sharply decreased as increased soil strength higher than $2kgf/cm^2$ measured by ELE penetrometer showing curvillinear regression. However, it was low regardless of soil strength when soil water retention was 10 bars in sandy loam soil. 3. From the pot experiment, the total length of roots were longer in loam soil than in sandy loam soil and was longer in the soils with lower bulk density. The average radius of fine roots grown in sandy loam soil was larger than that grown in loam soil. The total surface area of roots was greater in the loam soil with low bulk density than in the sandy loam soil with high bulk density as the total length of roots. 4. The amounts of nutrient uptake by soybean shoots were greater in loam soil primarily due to more production of dry matter than in sandy loam soil. The nitrogen influx rates through the unit surface area were 597 to $753nmoles/day-cm^2$ in loam soil and 222 to $365nmoles/day\;cm^2$ in sandy loam soilshowing higher value in higher bulk density. The potasium influx rates were 99 to $175nmoles/day-cm^2$, and those of phosphate were 26 to $46nmoles/day\;cm^2$. Those of Ca and Mg were 175 to 246 and 163 to $205nmoles/day\;cm^2$. The difference in nutrient influx rates between bulk densities of these elements were lower than that of nitrogen.

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Measuring Consumer-Brand Relationship Quality (소비자-브랜드 관계 품질 측정에 관한 연구)

  • Kang, Myung-Soo;Kim, Byoung-Jai;Shin, Jong-Chil
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.2
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    • pp.111-131
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    • 2007
  • As a brand becomes a core asset in creating a corporation's value, brand marketing has become one of core strategies that corporations pursue. Recently, for customer relationship management, possession and consumption of goods were centered on brand for the management. Thus, management related to this matter was developed. The main reason of the increased interest on the relationship between the brand and the consumer is due to acquisition of individual consumers and development of relationship with those consumers. Along with the development of relationship, a corporation is able to establish long-term relationships. This has become a competitive advantage for the corporation. All of these processes became the strategic assets of corporations. The importance and the increase of interest of a brand have also become a big issue academically. Brand equity, brand extension, brand identity, brand relationship, and brand community are the results derived from the interest of a brand. More specifically, in marketing, the study of brands has been led to the study of factors related to building of powerful brands and the process of building the brand. Recently, studies concentrated primarily on the consumer-brand relationship. The reason is that brand loyalty can not explain the dynamic quality aspects of loyalty, the consumer-brand relationship building process, and especially interactions between the brands and the consumers. In the studies of consumer-brand relationship, a brand is not just limited to possession or consumption objectives, but rather conceptualized as partners. Most of the studies from the past concentrated on the results of qualitative analysis of consumer-brand relationship to show the depth and width of the performance of consumer-brand relationship. Studies in Korea have been the same. Recently, studies of consumer-brand relationship started to concentrate on quantitative analysis rather than qualitative analysis or even go further with quantitative analysis to show effecting factors of consumer-brand relationship. Studies of new quantitative approaches show the possibilities of using the results as a new concept of viewing consumer-brand relationship and possibilities of applying these new concepts on marketing. Studies of consumer-brand relationship with quantitative approach already exist, but none of them include sub-dimensions of consumer-brand relationship, which presents theoretical proofs for measurement. In other words, most studies add up or average out the sub-dimensions of consumer-brand relationship. However, to do these kind of studies, precondition of sub-dimensions being in identical constructs is necessary. Therefore, most of the studies from the past do not meet conditions of sub-dimensions being as one dimension construct. From this, we question the validity of past studies and their limits. The main purpose of this paper is to overcome the limits shown from the past studies by practical use of previous studies on sub-dimensions in a one-dimensional construct (Naver & Slater, 1990; Cronin & Taylor, 1992; Chang & Chen, 1998). In this study, two arbitrary groups were classified to evaluate reliability of the measurements and reliability analyses were pursued on each group. For convergent validity, correlations, Cronbach's, one-factor solution exploratory analysis were used. For discriminant validity correlation of consumer-brand relationship was compared with that of an involvement, which is a similar concept with consumer-based relationship. It also indicated dependent correlations by Cohen and Cohen (1975, p.35) and results showed that it was different constructs from 6 sub-dimensions of consumer-brand relationship. Through the results of studies mentioned above, we were able to finalize that sub-dimensions of consumer-brand relationship can viewed from one-dimensional constructs. This means that the one-dimensional construct of consumer-brand relationship can be viewed with reliability and validity. The result of this research is theoretically meaningful in that it assumes consumer-brand relationship in a one-dimensional construct and provides the basis of methodologies which are previously preformed. It is thought that this research also provides the possibility of new research on consumer-brand relationship in that it gives root to the fact that it is possible to manipulate one-dimensional constructs consisting of consumer-brand relationship. In the case of previous research on consumer-brand relationship, consumer-brand relationship is classified into several types on the basis of components consisting of consumer-brand relationship and a number of studies have been performed with priority given to the types. However, as we can possibly manipulate a one-dimensional construct through this research, it is expected that various studies which make the level or strength of consumer-brand relationship practical application of construct will be performed, and not research focused on separate types of consumer-brand relationship. Additionally, we have the theoretical basis of probability in which to manipulate the consumer-brand relationship with one-dimensional constructs. It is anticipated that studies using this construct, which is consumer-brand relationship, practical use of dependent variables, parameters, mediators, and so on, will be performed.

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