• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.81-86
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• 2019

In X-ray image, the role of filtration through the filter is to reduce the exposure of the patient by using photon which is useful in formation of the image, and at the same time, enhance the contrast of the image. During interaction between photon and object, low energy X-rays are absorbed from the site of a few cm of the first patient's tissue, and high energy X-rays are the one which form the image. Therefore, the radiation filter absorbs low energy X-ray in order to lower the exposure of the patient and improve the quality of the image. The purpose of this study is to compare the effect on the image quality by differences of added filter through simulation image and actual radiation image. For that purpose, we used Geant4 Application for Tomographic Emission (GATE) as a tool for Monte Carlo simulation. We set actual size, shape and material of Polymethylmethacrylate (PMMA) Phantom on GATE and differentiated the parameter of added filter. Also, we took image of PMMA phantom with same parameter of added filter by digital radiography (DR). Than we performed contrast-to-noise ratio (CNR) evaluation on both simulation image and actual DR image by Image J. Finally, we observed the effect on image quality due to different thickness of added filter, and compared two images' CNR evaluation's transitions of change. The result of this experiment showed decreasing in the progress of CNR on both DR and simulation image. It is ultimately caused by decreasing in contrast on image. In theory, contrast decrease with kVp increased. Given that condition, this study found out that filter makes not only decreasing total dose by absorbing low energy of X-ray, but also increasing average energy of X-ray.

• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.21-33
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• 2019

This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.306-318
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• 2018

In order to evaluate the seismic capacity of massive vertical type breakwaters which have intensively been deployed along the coast of South Korea over the last two decades, we carry out the preliminary numerical simulation against the PoHang, GyeongJu, Hachinohe 1, Hachinohe 2, Ofunato, and artificial seismic waves based on the measured time series of ground acceleration. Numerical result shows that significant sliding can be resulted in once non-negligible portion of seismic energy is shifted toward the longer period during its propagation process toward the ground surface in a form of shear wave. It is well known that during these propagation process, shear waves due to the seismic activity would be amplified, and non-negligible portion of seismic energy be shifted toward the longer period. Among these, the shift of seismic energy toward the longer period is induced by the viscosity and internal friction intrinsic in the soil. On the other hand, the amplification of shear waves can be attributed to the fact that the shear modulus is getting smaller toward the ground surface following the descending effective stress toward the ground surface. And the weakened intensity of soil as the number of attacking shear waves are accumulated can also contribute these phenomenon (Das, 1993). In this rationale, we constitute the numerical model using the model by Hardin and Drnevich (1972) for the weakened shear modulus as shear waves go on, and shear wave equation, in the numerical integration of which $Newmark-{\beta}$ method and Modified Newton-Raphson method are evoked to take nonlinear stress-strain relationship into account. It is shown that the numerical model proposed in this study could duplicate the well known features of seismic shear waves such as that a great deal of probability mass is shifted toward the larger amplitude and longer period when shear waves propagate toward the ground surface.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.41-63
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• 2021

The purpose of this study was to investigate the nutritional knowledge and eating behavior of middle school students in Gwangju area in order to provide basic data for the development of home economics curriculum that can help the students form healthy eating habits. For this purpose, a self-administered questionnaire was distributed to middle school students in Gwangju area. A total of 330 questionnaires were collected by convenience sampling and analyzed using SPSS(Statistics Package for the Social Science) Version 20.0 for Windows. Results of this study are as follows. First, school curriculum session ranked top(31.82%) on the list of sources for middle school students to acquire nutrition knowledge. Second, the mean score of nutrition knowledge of all respondents was moderately high(14.33 points out of maximum 20 points). In terms of nutrition knowledge by gender, female students had a higher level of nutrition knowledge in the 'Food' domain than their male counterparts(p<0.05). With regard to nutrition knowledge by grade, Grade 9 showed a higher score than Grade 7 and 8(p<0.001). Third, the mean score of eating behavior of all respondents was at an average level(69.75 out of 100 points). In terms of eating behavior by gender, male students showed a higher score than their female counterparts(p<0.05). In particular, male students had higher scores than female students for the following items: "I exercise regularly after school"(p<0.001); "I regularly eat meal three times per day"(p<0.01); "I don't skip breakfast"(p<0.01); and "I don't eat sweet food often"(p<0.01). In terms of eating behavior by grade, Grade 9 showed higher scores than Grades 7 and 8 for the following items: "I eat meal out of thankfulness for those who have prepared food"(p<0.01) and "I eat grains for every meal"(p<0.01). Finally, with regard to eating behavior depending on the level of nutrition knowledge, the 'Upper' and 'Middle' groups had higher scores for eating behavior than the 'Lower' group, indicating that a lower level of nutrition knowledge resulted in a lower score in eating behavior. Based on the above results, home economics teachers responsible for dietary education should have a greater sense of mission and pride and make more efforts to improve nutrition knowledge and eating behavior of middle school students.

• Journal of Christian Education in Korea
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• v.66
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• pp.75-112
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• 2021

This study is purposed to prepare students in theological universities so that they contribute to their faith community as well as the broader social community in future through developing a practical course model for education of character formation. Facing the challenge of a high-tech revolution being progressed globally in this period, theological seminaries as the Christian-affiliated institute of higher education see the necessity to nurture their learners' competency of holistic personality comprehending cognitive, affective, behavioral, and more spiritual maturity as well as specialty in each subject matter. The holistic character capability of seminarians is closely related not only to their own self-realization, but also social community's well-being. This research had the following content and results. Chapter 1 brought up a subject to educational needs of the holistic character formation in the theological seminaries to meet the rapidly changing times. Chapter 2 considered the importance of character formation in the curriculum of the universities and theological seminaries in the times of high-tech revolution through the literature reviews related to. Chapter 3 clarified the elements of character education to be placed emphasis on theological seminaries and established the way of course planning. Chapter 4, using a course of Christian social education for illustration, described in order the whole process of course planning comprehending the need of planning, description of course concept, establishment and definition of learning outcomes, organization of learning experience(course content), teaching-learning activities, evaluation of learning outcome, and course improvement, which was visualized with the chart of the process of course design. Also, it provided a practical illustration of the conceptual map, an outline of content and an organization of units, and scope-sequence chart. Finally, chapter 5 gave an syllabus example in an integrative and digestive form as the course plan to be distributed to the students, which is the final result produced through the whole process of course planning. This research is intended not to present a overall curriculum planning of the university-level in the theological seminaries, but to develop a course-level curriculum focused on the formation of character. The author hope that this study would be used as a guideline in developing a course model to nurture the capability of the learners' holistic character.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.95-104
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• 2011

Distribution types of native conifers (Juniperus chinensis, Pinus parviflora, Tusga sieboldii and Taxus cuspidata var. latifolia) were studied by phytosociological investigation and ZM method in Ulleung Island, South Korea. Two main types were divided maritime vegetation (Juniperus chinensis forest) and mountain vegetation (Taxus cuspidata var. latifolia forest and Pinus parviflora-Tusga sieboldii forest). The former was divided into sea cliff distribution (J-SC) and sea ridge distribution (J-SR) type. The latter was classified 7 distribution types; Taxus cuspidata var. latifolia forest was rock distribution (Ta-R) and mountain slope distribution (Ta-MS) type, and Pinus parviflora-Tusga sieboldii forest was rock distribution (P T-R), upper and ridge distribution (P T-UR, 3 units sub-types:1sub, 2sub, 3sub), and Mountain slope distribution (P T-MS) type. It was considered that J-SC, Ta- R, and P T-R were maintained by topographic climax, but J-SR, Ta-MS, P T-UR and P T-MS were the process of vegetation succession. Distribution types of topographic climax are entrusted to process of vegetation succession. Types in the process of vegetation succession will be needed tending of forest to promote saplings growth and seedlings germination. Especially in order to restore Tsuga sieboldii forest should be afforest and make forest gap because It is mid shade tolerant tree and purity percentage of its seed is 1~2%. It was considered that the composition of group mixture forest constituted Pinus parviflora, Tsuga sieboldii, Taxus cuspidata, Camellia japonica, Machilus thunbergii and Acer okamotoanum, etc. will be able to restore native vegetation, after take the form of forest gap by strong thinning and pruning of Pinus thunbergii forest.

• The Journal of Korean Philosophical History
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• no.31
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• pp.7-32
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• 2011

Cheng Yi(程?, 1033~1107) understood that nature is full of "changes(易)". And he noted that human being as part of nature also exists only in a series of changes, i.e. birth, growth, extinction and death. All things including human being arise from the same principle, or "Heavenly Principle." Hence human being can fundamentally be one with all other beings, or nature. It is called "Unity of all things(萬物一體)" and "Unity of heaven and human(天人合一)." This philosophical perspective cannot be regarded as being unique to Cheng only; neo-Confucian predecessors called "the five masters of the Northern Song(北宋五子)" anticipated Cheng's vision already. Nevertheless, Cheng elaborated on the shared vision, revealing his philosophical uniqueness. Cheng maintains that only human being receives the principle in the unstained form, and thereby is capable of being one with nature. The one who realizes her/his potential to be one with nature is a sage(聖人); for Cheng, the order and pattern found in nature is nothing other than moral principle that human beings have to live up to and vice versa. Cheng's idea on the principle which human being receives from Heaven no doubt relates to Mencian notion of the innate goodness of human nature(性善); the innate goodness of human nature is no other than Heavenly Principle, and to become a sage depends on whether one can realize her/his potential - human nature, i.e. Heavenly Principle in her/himself. For Cheng, human nature tantamount to Heavenly Principle has no evil quality; all the evil in the world comes from imperfect "physical endowment(氣質)," or "capacity(才)" which is various from person to person, making various personalities. Accordingly, the task of moral cultivation in Cheng's theory can translate into the matter of rectification of one's physical endowment.

• (The)Study of the Eastern Classic
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• no.71
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• pp.147-180
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• 2018

Seokjeong JEONG-JIK LEE is a scholar who tried to render a form of service for his country by writing works of literature during the crisis of the Period of Modern Enlightenment. He mainly expressed his perception of reality through an evaluation of historical figures. He left behind a text on the Analects of Confucius, which is known as the '10 questions and answers regarding the Analects of Confucius', in his posthumous work. It seems that he wrote it to be used as lecture material for his students. The purpose of this thesis is to analyze his recognition to the Analects of Confucius and its learning direction expressed in the writing '10 questions and answers regarding the Analects of Confucius'. With respect to the word ren(仁), which is the most fundamental concept of the Analects, he viewed his life in an introspective way from the standpoint of a 'Hoinyupe(好仁有蔽)', which means that if you like kindness and fairness but don't like learning it, then there will be negative effects, and through the 'Gwangwajiin(觀過知仁)', which means that you will know for sure kindness and fairness when you observe wrongdoing, not the general viewpoint of 'Humaneness or Love'. He tried to determine the meaning of ren, and virtue(德) through a common denominator from an overall point of view. It might have been a reflection of his thoughts that a sound comprehension of powerful countries was needed. In terms of relationship between Gunja(君子) and Myeong(命), Gunja needs to make constant efforts to understand Myeong as a talented person who can maintain order. The direction of learning was examined under three categories: Jongipjibang (從入之方), Gunjajiryu(君子之類), and Sumunihae(隨文而解). Jongipjibang is defined as a way to complement the weaknesses of leaners according to their characteristics and it promotes a focus on pushing ethics into practice rather than acquiring knowledge as it is today. Gunja was classified into 3 stages. However, it merely provides standards to help learners' understandings, so not all students may fall into these stages. Sumunihae gives explanations of commentaries on the book. Seokjeong remarked that the meaning was not different even if the same concept was annotated differently in the "Four Books". This is because the context was emphasized according to the principle of 'Sosisojeol Pilchakpilseom (所始所切, 必着必贍)'.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.274-291
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• 2020

This year is the 50th anniversary of the adoption by UNESCO in 1970 of the Convention on the Means of Prohibiting and Preventing the Illicit Import, Export, and Transfer of Ownership of Cultural Property (the '1970 Convention'). Since its ratification of the 1970 Convention in 1983, the Republic of Korea has domestically implemented the Convention through its Cultural Heritage Protection Act, which was first enacted in 1962. This is a different form of implementation than is normally used for other UNESCO Conventions on cultural heritage, in that the Republic of Korea has recently adopted special acts to enforce the 2003 Convention for the Safeguarding of Intangible Cultural Heritage and the 1972 Convention concerning the Protection of the World Cultural and Natural Heritage. In addition, the 1970 Convention has been developed further through the introduction of new Operational Guidelines in 2015 for the concrete enforcement of the Convention, which has provided momentum for the Republic of Korea to analyze its current national legislation related to the 1970 Convention as well as consider its amendment in the future. Overall, the Cultural Heritage Protection Act of the Republic of Korea effectively reflects the duties of States Parties under the 1970 Convention. These include measures to introduce export certificates, prohibit the import of stolen cultural property, return other state parties' cultural property, and impose penalties or administrative sanctions in the event of any infringements. Indeed, the Republic of Korea's implementation of the 1970 Convention was introduced as an example of good practice at the Meeting of State Parties in 2019. However, changes in the illegal market for cultural property and development of relevant international law and measures imply that there still exists room for improvement concerning the legal implementation of the 1970 Convention at the national level. In particular, the Operational Guidelines recommend States Parties to adopt legal measures in two respects: detailed criteria for due diligence in assessing bona-fide purchasers, referring to the 1995 UNIDROIT Convention on Stolen or Illegally Exported Cultural Objects, and measures to address the emerging issue of illegal trade in cultural property on internet platforms. Amendment of the Cultural Heritage Protection Act and other relevant laws should be considered in order to duly reflect these issues. Taking that opportunity, concrete provisions to facilitate international cooperation in respect of the implementation of the 1970 Convention could be introduced as well. Such measures could be expected to strengthen the Republic of Korea's international legal cooperation to respond to the changing environment regarding illicit trafficking of cultural property and its restitution.

• Industry Promotion Research
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• v.7 no.2
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• pp.43-49
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• 2022

This study aims to study Esping-Anderson's theory of welfare state system, develop a model of welfare state suitable for Korea's situation, and apply it to reality. In this research method, basic research and analysis of ideology is used, focusing on Esping-Anderson's welfare state system theory, and applying it appropriately to the Korean situation. Studies on the model of the welfare state have been studied after the classification of complementary and institutional models asserted by Willensky and Lebo in 1965. In addition, Esping-Andersen asserts three things as a model of the welfare state according to ideology. First, the role of the market is central to the liberal welfare system that best fits the image of classical capitalism, and individualistic solidarity through the market. The role of the state or family, which can be a hindrance, is actually marginalized. In addition, in order to maximize individualistic solidarity through the market, de-commodification in the national domain tends to be minimized. Second, the conservative welfare system has a strong familistic element, so the source of social solidarity is the family, and the state plays a role of supporting and supplementing the characteristics of this family. In the conservative system, de-commodification appears to be high among household heads, or the welfare system takes on a corporatist and nationalistic form, it can be said that these characteristics are reflected. Third, in the social democratic welfare system, the source of social solidarity is the state. Therefore, the role of the state is large, the state has a high possibility of decommodification, and it has the characteristics of substitutes for the family and the market through universalist intervention. This study applies Esping-Anderson's three welfare state models to study a model suitable for the Korean situation. In conclusion, Esping-Anderson's three welfare state models can be classified into a market-oriented model based on a liberal welfare system, a status-oriented model based on a conservative corporatist welfare system, and a solidarity-oriented model based on a social-democratic welfare system, presented a compromise between liberalism and conservatism as a Korean model.