• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.293-300
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• 2008

Efficient designing of SRM Grains in the field of Rocketry is still the main test for most of the nations of world for scientific studies, commercial and military applications. There is a strong need to enhance thrust, improve the effectiveness of SRM and reduce mass of motor and burning time so as to allow the general design to increase the weight of payload/on board electronics. Moreover burning time can be increased while keeping the weight of the propellant and thrust in desired range, so as to give the time to control / general design group in active phase for incorporating delayed cut off if required. A mathematical design, optimization & analysis technique for Slotted Tube Grain has been discussed in this paper. In order to avoid the uncertainties that whether the Slotted Tube grain configuration being designed is best suited for achieving the set design goals and optimal of all the available designs or not, an efficient technique for designing SRM Grain and then getting optimal solution is must. The research work proposed herein addresses and emphasizes a design methodology to design and optimize Slotted Tube Grain considering particular test cases for which the design objectives and constraints have been given. In depth study of the optimized solution have been conducted thereby affects of all the independent parametric design variables on optimal solution & design objectives have been examined and analyzed in detail. In doing so, the design objectives and constraints have been set, geometric parameters of slotted tube grain have been identified, performance prediction parameters have been calculated, thereafter preliminary designs completed and finally optimal design reached. A Software has been developed in MATLAB for designing and optimization of Slotted Tube grains.

• Advances in aircraft and spacecraft science
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• 제3권3호
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• pp.351-366
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• 2016

Macroperforations improve the sound absorption performance of porous materials in acoustic cavities and in waveguides. In an acoustic cavity, enhanced noise reduction is achieved using porous materials having macroperforations. Double porosity materials are obtained by filling these macroperforations with different poroelastic materials having distinct physical properties. The locations of macroperforations in porous layers can be chosen based on cavity mode shapes. In this paper, the effect of variation of macroporosity and double porosity in porous materials on noise reduction in an acoustic cavity is presented. This analysis is done keeping each perforation size constant. Macroporosity of a porous material is the fraction of area covered by macro holes over the entire porous layer. The number of macroperforations decides macroporosity value. The system under investigation is an acoustic cavity having a layer of poroelastic material rigidly attached on one side and excited by an internal point source. The overall sound pressure level (SPL) inside the cavity coupled with porous layer is calculated using mixed displacement-pressure finite element formulation based on Biot-Allard theory. A 32 node, cubic polynomial brick element is used for discretization of both the cavity and the porous layer. The overall SPL in the cavity lined with porous layer is calculated for various macroporosities ranging from 0.05 to 0.4. The results show that variation in macroporosity of the porous layer affects the overall SPL inside the cavity. This variation in macroporosity is based on the cavity mode shapes. The optimum range of macroporosities in poroelastic layer is determined from this analysis. Next, SPL is calculated considering periodic and nodal line based optimum macroporosity. The corresponding results show that locations of macroperforations based on mode shapes of the acoustic cavity yield better noise reduction compared to those based on nodal lines or periodic macroperforations in poroelastic material layer. Finally, the effectiveness of double porosity materials in terms of overall sound pressure level, compared to equivolume double layer poroelastic materials is investigated; for this the double porosity material is obtained by filling the macroperforations based on mode shapes of the acoustic cavity.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.105-112
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• 2022

The development and spread of IT-technologies has raised interest in teaching programming pupils. The article deals with problems related to programming and ways to overcome them. The importance of programming skills is emphasized, as this process promotes the formation of algorithmic thinking of pupils. The authors determined the level of pupils' interest to programing learning depending on the age. The analysis has showed that the natural interest of younger pupils in programming is decreasing over the years and in the most productive period of its study is minimized. It is revealed that senior school pupils are characterized by low level of interest in the study of programming; lack of motivation; the presence of psychological blocks on their own abilities in the context of programming; law level of computer science understanding. To overcome these problems, we conducted the second stage of the experiment, which was based on a change in the approach to programing learning, which involved pupils of non-specialized classes of senior school (experimental group). During the study of programming, special attention was paid to the motivational and psychological component, as well as the use of game technologies and teamwork of pupils. The results of the pedagogical experiment on studying the effectiveness of teaching programming for pupils of nonspecialized classes are presented. Improvement of the results provided the use of social and cognitive motives; application of verbal and non-verbal, external and internal means; communicative attacks; stimulation and psychological setting; game techniques, independent work and reflection, teamwork. The positive effect of the implemented methods is shown by the results verified by the methods of mathematical statistics in the experimental and control groups of pupils.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.146-152
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• 2022

The National Agency for Quality Assurance in Higher Education plays a crucial role in education in Ukraine, as an independent entity creates and ensures quality standards of higher education, which allow to properly implement the educational policy of the state, develop the economy and society as a whole. The purpose of the article: to reveal the crucial role of the National Agency for Quality Assurance in Higher Education to create quality management of higher education institutions, to show its mechanism as an independent entity that creates and ensures quality standards of higher education. and society as a whole. The mission of the National Agency for Quality Assurance in Higher Education is to become a catalyst for positive changes in higher education and the formation of a culture of its quality. The strategic goals of the National Agency are implemented in three main areas: the quality of educational services, recognition of the quality of scientific results, ensuring the systemic impact of the National Agency. The National Agency for Quality Assurance in Higher Education exercises various powers, which can be divided into: regulatory, analytical, accreditation, control, communication. The effectiveness of the work of the National Agency for Quality Assurance in Higher Education for 2020 has been proved. The results of a survey conducted by 183 higher education institutions of Ukraine conducted by the National Agency for Quality Assurance in Higher Education are shown. Emphasis was placed on the development of "Recommendations of the National Agency for Quality Assurance in Higher Education regarding the introduction of an internal quality assurance system." The international activity and international recognition of the National Agency for Quality Assurance in Higher Education are shown.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.447-448
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• 2021

경계 기반 보안 관리체계는 보안 솔루션 배치가 쉽고, 그 운영 효율성이 높은 장점이 있다. 경계 기반 보안 관리체계는 외부에서 발생하는 보안 위협을 차단하기 적합하지만, 내부에서 발생하는 보안 위협을 차단하기에는 부적합하다. 안타깝게도 내부에서 발생하는 보안 위협은 갈수록 그 빈도가 증가하고 있다. 이러한 한계점을 극복하기 위하여 제로 트러스트 모델이 제안되었다. 제로 트러스트 모델에서는 다양한 정보 자원에 접근하는 주체의 행위를 분석하기 위하여, 실시간 모니터링 기능을 요구하고 있다. 그러나 시스템에 신뢰된 것으로 확인된 주체의 파일 접근을 실시간으로 모니터링 하는 것은 그 한계가 있다. 이에 따라 본 연구에서는 사용자의 파일 접근을 실시간으로 모니터링 할 수 있는 방법을 제안한다. 제안하는 모니터링 방법의 실효성을 검증하기 위하여 실증 구현 후 목표하는 기능을 검증하였다. 그 결과, 본 연구에서 제안하는 방법은 파일에 대한 접근을 실시간으로 모니터링 할 수 있다고 확인되었다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4527-4542
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• 2023

The present microbial reinforcement of rock and soil exhibits limitations, such as uneven reinforcement effectiveness and low calcium carbonate generation rate, resulting in limited solidification strength. This study introduces electroosmosis as a standard microbial grouting reinforcement technique and investigates its solidification effects on microbial-reinforced uranium tailings. The most effective electroosmosis effect on uranium tailings occurs under a potential gradient of 1.25 V/cm. The findings indicate that a weak electric field can effectively promote microbial growth and biological activity and accelerate bacterial metabolism. The largest calcium carbonate production occurred under the gradient of 0.5 V/cm, featuring a good crystal combination and the best cementation effect. Staged electroosmosis and electrode conversion efficiently drive the migration of anions and cations. Under electroosmosis, the cohesion of uranium tailings reinforced by microorganisms increased by 37.3% and 64.8% compared to those reinforced by common microorganisms and undisturbed uranium tailings, respectively. The internal friction angle is also improved, significantly enhancing the uniformity of reinforcement and a denser and stronger microscopic structure. This research demonstrates that MICP technology enhances the solidification effects and uniformity of uranium tailings, providing a novel approach to maintaining the safety and stability of uranium tailings dams.

• Tuberculosis and Respiratory Diseases
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• 제57권6호
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• pp.557-566
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• 2004

연구배경 : 비소세포폐암 중 IIIA병기는 같은 병기라도 다양한 임상적 경과를 밟고 어느 한가지 치료만으로는 치료 성적이 좋지 못하다. 이에 최근에는 다각적치료(항암, 화학치료, 방사선치료 및 수술적 치료)가 치료의 근간이 되고 있고 이에 대한 연구가 많이 시도되고 있으며 일부에서는 긍정적인 결과를 보고 하고 있다. 이에 저자들은 유도화학요법에 근간을 둔 다각적 치료의 효과를 살펴보고자 연구를 계획하였다. 방 법 : 1997.1월부터 2002.12월까지 충남대학교 병원에 내원하여 임상적으로 비소세포폐암 IIIA병기 진단을 받고 초치료로 유도화학치료를 시행받은 환자에 대하여 다각적 치료의 반응률, 재발율 및 생존기간등을 살펴보았다. 결 과 : 1) 유도화학요법은 74명에게서 시행되었고 반응률은 44.6%(완전관해 1.4% 및 부분반응 3.2%)였고, 고전적약(VPP)과 신약과의 반응률은 차이가 없었다(38.9%vs. 50%, p=0.506). 임파선의 반응률은 다발성 N2이상 병기로 수술적 치료에 어려움이 있다고 판단됐던 37명중 18명(54%)에서 단발성 N2이하로 병기하향을 보였고 이중 수술거부 6명과 폐기능문제 4명을 제외한 8명(21%)이 수술을 시행 받았다. 단발성 N2병기의 경우는 37명중 33명(89%)에게서 단발성 N2이하로 병기유지 내지 하향을 보였고 수술거부 7명과 폐기능문제 5명을 제외한 21명(56.7%)이 수술을 시행 받았다. 유도화학요법 후 다발성 N2였으나 수술적 절제가 가능하다고 판단됐던 4명의 경우에도 수술이 시행되어 전체 환자 중 수술적 치료는 33명(44.5%)에게서 시행되었으며, 완전절제는 30명(40.5%)이었고, 2명(2.6%)의 경우는 불완전 절제, 그리고 1명(1.3%)의 경우는 산소 포화도가 유지가 되지 않아 바로 봉합하였다. 2) 유도화학요법후 WHO기준 3이상의 호중구 감소증은 20명(25.7%)에서 발생하였고 이에 병발된 폐렴은 3명에게서 발생하였으나 이로 인한 사망은 없었다. 3) 수술적 절제가 불가능하여 방사선 치료를 시행하였던 27명의 반응률은 완전관해가 4.8%였고 부분반응은 11.9%였다. 4) 완전 절제되었던 군의 무병지속기간은 13.6개월이었고, 2년의 추적관찰기간 시점의 재발률은 52%였으며, 추가 방사선 치료군의 국소 재발율은 의미있게 적었다(0% vs. 40%, 0.02). 완전 절제되지 못하였거나 불완전 절제된 군의 무진행 질병기간은 11.2개월이었고, 2년의 추적관찰기간 시점의 병의 진행률은 66.7%였다. 5) 전체 대상환자의 중앙생존기간은 25.1개월이었고, 유도화학요법 후 수술 적으로 완전절제를 이루었던 군이 국소 치료로 방사선 치료를 시행하였던 군에 비하여 생존기간이 유의하게 길었지만(31.7개월 vs. 26.1개월, p=0.04), 완전절제 된 군의 추가 방사선 치료에 따른 생존 이득은 없었다. (34.9개월 vs. 32.2개월, p=0.48) 결 론 : 이상의 결과로 임상적 IIIA병기 비소세포폐암의 치료로 다각적 치료시 유도화학요법 후 가능하다며 수술적으로 완전절제를 이루는 것이 가장 좋은 치료라 생각된다. 하지만 전체적인 생존율은 그다지 높지 못하여 유도화학요법시 추가적인 방사선 치료, 수술 후 보조적 항암화학요법, 그리고 생물학적 치료제 등에 대한 보다 많은 3상 연구가 필요하리라 생각된다.

• Journal of Acupuncture Research
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• 제21권3호
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• pp.265-282
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• 2004

Objective : The aim of this study was to review systemically clinical trials on the effectiveness and safety of herbal medicines in the treatment of osteoarthritis. Methods : Computerized literature searches were carried out on seven electronic databases, and hand-searching on some chinese medical journals in library of Kyung Hee Medical Center. Trial data were extracted in a standardized, predefined manner and assessed independently. Results : 1. Thirty reports of clinical trials and two reports of meta-analyses concerning herbal medicine were collected and reviewed. Among these reports three medical herbs were applied as topical medicine and others as internal medicine. 2. The western studies established NSAIDs or placebo as their control group. Five chinese reports established formulated herb pill(Ruanshnagshenjin pill) as their control group and Six did not establish a control group at all. 3. ACR was the most highly used diagnostic criteria in the western studies while the Chinese used their official criteria established by their government or the criteria of their text books. 4. 20 reports chose the Lequesne functional index, SHAQ, WOMAC OA index, AIMS, and their own unique scoring system as the criteria of analysing the effect. Others chose clinical symptoms, articular functions, and lab finding as their criteria. 5. 7 single herbs and 19 formulated herbs were studied. Among the formulated herbs, Achyranthes japonica was studied in 10 of the studies and Angelica gigantis Radix in 8, making them the most often studied herbs among the studies.

• Journal of Korea Trade
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• 제23권8호
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• pp.110-131
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• 2019

Purpose - This paper investigates the implications for facilitating trade in the products of Industry 4.0. To identify the issues caused by the conflicts of policy objectives such as applying the tariff concession under the ITA and imposing the export control, by exploring the case of classification of drones. Design/methodology - We adopted a single case study method to gain a deeper understanding of the complex and multifaceted issues of Customs classification in the context of facilitating trade in the products of Industry 4.0. This study employs the case of drones to explore how these issues of Customs classification affect trade facilitation. We ensured the internal validity of the study by confirming the pattern of the results with the existing theories. Findings - Our main findings can be summarised as follows: the intrinsic nature of the products that converge several technologies causes issues in the classification. The inconsistency in product classification delays customs clearance by hindering the Customs risk-management system that pinpoints products subject to controls. To address the issues, therefore, we proposed fundamental reforms of Customs to empower themselves with management roles. Facilitating trade in the products of Industry 4.0 requires more enhanced Customs capability. Therefore, the reforms should include comprehensive capacity-building activities, such as changes in staff-trainings, promotion system, organisation and culture. Customs also need roles in robust designing of cooperative systems to compensate for the lacks of controls and to ensure concrete risk management for expedited Customs procedures. As well, by equipping the Single Window of Customs with crucial control functions of other ministries, Customs need to support the cooperation. The role of harmonising various preaudits of other ministries with its own is another essential role that ensures predictability of clearance procedure. Originality/value - There are scanty studies in the field of knowledge about what obstacles exist and what solution is available in the course of transforming to 'Industry 4.0'. In filling out the gap of knowledge, this paper is of academic significance in that it applies the research theory on trade facilitation for the specific cases of classification of the product of Industry 4.0 to verify its effectiveness and to extend the subject of the studies to the scope of Industry 4.0. It also has practical significance in that the results have provided implications for reforms of Customs procedures to facilitate trade in the products of Industry 4.0.

• 대한한의학원전학회지
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• 제23권4호
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• pp.63-102
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• 2010

Purpose : To propose various types of clinical research which is feasible for botanical new drug (IND) development processes, and suggest essential steps to development of study protocol for IND. Methods : Literature-based discussions and one research group's experience is given regarding domestic act, regulation, and system. Results : In order to get an approval of IND for botanical drug in Korea there are several types of clinical research to conduct. In quality control steps for standardized medicinal herbs, case reports or case series can be conducted, and for good manufacturing practice(GMP) steps, we can conduct case reports, case series, and retrospective cohort studies. In addition, as long as we gathered good laboratory practice(GLP) data we can conduct up to quasi-experimental studies and clinical trials including investigator initiated trials. In order to conduct these studies development of study protocol is essential. First, we obtain historical evidence including target disease and indication, efficacy, safety, and endpoints by reviewing medical classics. Second, we obtain clinically and statistically important data by conducting non-clinical studies, observation studies, and quasi-experimental studies. Third, we generate research hypotheses and purposes and explore methodologies, endpoints, clinical practice guidelines, cost-effectiveness, and commercial potential. Finally, we develop study protocol with aid of biostatistician or expert in contract research organization. Discussions and conclusions : This study have obvious limitations in that most thoughts, suggestions, and proposes are from one research group's experience. Therefore, we hope to see various types of research in this topic and process from other research group as well.