• International Journal of Control, Automation, and Systems
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• 제6권5호
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• pp.677-688
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• 2008

In this paper, the general problem of impedance control for a robotic manipulator with a moving flexible base is addressed. Impedance control imposes a relation between force and displacement at the contact point with the environment. The concept of impedance control of flexible base mobile manipulator is rather new and is being considered for first time using singular perturbation and new sliding mode control methods by authors. Initially slow and fast dynamics of robot are decoupled using singular perturbation method. Slow dynamics represents the dynamics of the manipulator with rigid base. Fast dynamics is the equivalent effect of the flexibility in the base. Then, using sliding mode control method, an impedance control law is derived for the slow dynamics. The asymptotic stability of the overall system is guaranteed using a combined control law comprising the impedance control law and a feedback control law for the fast dynamics. As first time, base flexibility was analyzed accurately in this paper for flexible base moving manipulator (FBMM). General dynamic decoupling, whole system stability guarantee and new composed robust control method were proposed. This proposed Sliding Mode Impedance Control Method (SMIC) was simulated for two FBMM models. First model is a simple FBMM composed of a 2 DOFs planar manipulator and a single DOF moving base with flexibility in between. Second FBMM model is a complete advanced 10 DOF FBMM composed of a 4 DOF manipulator and a 6 DOF moving base with flexibility. This controller provides desired position/force control accurately with satisfactory damped vibrations especially at the point of contact. This is the first time that SMIC was addressed for FBMM.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.274-284
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• 2022

By explaining the essence of corporate governance as well as disclosure and transparency, the study examined the guarantees of applying disclosure and transparency to firms listed on the Saudi stock exchange. The research also addressed the disclosure and transparency duties of firms listed on the Saudi stock exchange. Finance to prepare a prospectus, as the Capital Market Authority's regulations required that the prospectus includes information that enables the investor in securities to make his investment decision based on real foundations based on the issuing company's financial position and to ensure that companies fulfill that disclosure in the prospectus. Firms who fail to disclose are required by law to do so, and the Capital Market Authority's laws mandate companies listed on the financial market to regularly report fundamental events linked to the issuer or the securities issued by it. The Capital Market Authority must make it available to the public dealing with the business issuing the securities, and The Capital Market Authority's Law and Regulations have imposed fines on corporations that do not comply with disclosure and make the Board of Director's report available. The research focused on activities that the legislator deemed to be a breach of the obligation of openness, such as the danger of many measures aimed at ensuring the impartiality and transparency of trading in the Saudi financial market, as well as the absence of conflicts of interest. The research also addressed the sanctions imposed on The source for failing to meet the obligation of disclosure and openness, as well as the mechanisms of compensating persons harmed by the failure to meet that responsibility.

• 한국보건간호학회지
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• 제13권2호
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• pp.84-100
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• 1999

Caring is the essential and universal concept of underlying nursing. Exactly how caring attributes relate to nurses' perception in the context of a contemporary technological environment have yet to be operationlized. In total. 560 Registered Nurses from 5 different university hospitals were involved in this study which aimed to : investigate technological influence and caring attributes as perceived by nurse. Data were obtained using Technological Influence Questionnaire (TIQ) and Caring Attributes Questionnaires(CAQ) which developed by Arthur et al(1999). Data were analyzed using SAS program for frequency. t-test. ANOVA and Tukey's Studentized Range test. and Pearson correlation coefficients. The results were as follows : 1) The mean score of TIQ was 48.84 and special unit nurses' TIQ was higher than that of general ward nurses. 2) The mean score of CAQ was 237.02 and it showed significant differences in the following variables : age. religion. educational background. marital status. career, and position. 3) With regard to the mean item score of CAQ by 3 perspectives : theoretical perspectives score was 3.76. practical perspectives score was 4.03, and pedagogical perspectives score was 3.84. 4) The correlation between TIQ score and CAQ score was slightly moderate (r=.35), The CAQ mean scsre was significantly different accordig to the level of TIQ meen score. The CAQ mean score was $247.19(\pm18.17)$ in high TIQ(>mean+1SD) group, $236.21(\pm19.71)$ In moderate $TIQ(between\;mean{\pm}1SD) $ group, and $228.47(\pm18.07)$ in low TIQ( (mean-1SD) group. In conclusion, nurses perceived the CAQ differently by several demographic characteristics which relating to age. religion, eduacational background. marital status. career. and position. This study provides an important message for administrators and nurse educators by highlighting factors which can be addressed by education programs. staff development and appraisal. Further research is necessary to improve and refine the Korean version of TIQ and CAQ instead of Arthur et al's scales directly to Korean nurses.

• Korean Journal of Mathematics
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• 제20권1호
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• pp.137-159
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• 2012

영뉵 또는 영부족(盈不足)은 그 글자의 의미에서 보듯이 넘치는 것과 부족한 것에 관계된 '과부족'문제를 나타낼 때 사용되는 유용한 개념으로, 영부족술(盈不足術)은 과부족문제를 푸는 일종의 산법이다. 본 논문은 먼저 지금까지 영부족에 관하여 소개된 최근의 모든 논문을 분석하고, <구장산술 九章算術> 권칠(卷七) "영부족" 장의 대표문제를 통하여 영부족술의 내용과 산법으로써의 의미를 쉽게 이해할 수 있도록 새롭게 서술하였다. 그리고 서양에서 이중가정법(rule of double false position)으로 알려진 영부족에 관한 최근의 동서양 연구결과를 분석하여, 영부족술과 Cramer's Rule과의 관계 및 <산학보감 算學寶鑑>에 소개된 진화된 영부족술의 특징에 대하여 논하였다. 더 나아가 영부족술의 기원과 중국의 영부족술이 아랍을 거쳐 유럽으로 전파된 배경을 구체적으로 밝혔다.

• 한국항공우주학회지
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• 제42권6호
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• pp.505-514
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• 2014

본 논문은 의사위성 항법시스템을 이용하여 항공기, 선박 등에 정밀한 항법해를 제공할 경우 해수면의 반사파에 의한 영향으로 항법신호의 의사거리 추정 성능이 어떻게 변화하는지 분석하였다. 해수면 반사파의 영향을 최소화하기 위한 방안들로써 수신기 설계에 있어 상관기별 성능비교 분석을 통해 의사위성 항법시스템에 적절한 상관기를 제시하고자 하였으며, 다중 안테나 기법 사용을 제안하였다. 또한, 해수면 반사파를 회피하기 위한 가장 확실한 방안으로 송신소 위치 이동시의 실험값을 제시하여 해수면 반사파의 영향으로부터 항법 신호의 의사거리 추정 성능의 개선 정도를 분석하였다.

• 한국사회복지학
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• 제58권3호
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• pp.269-294
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• 2006

이 연구는 장애인복지학의 이론적 패러다임에 따라 한국장애인복지학의 연구동향에 관한 분석을 목적으로 한다. 즉, 장애인복지학의 기술적 이론적 분석을 통해 한국장애인복지학의 변화를 점검하고 향후 지향해야 할 방향성에 대한 논의의 장을 마련하고자 한다. 이를 위해 이 연구는 첫째, 사회복지학이 주 전공인 학회 중 학술진흥재단 등재지나 등재후보지로 등록된 학술지 9종을 대상으로 1979년부터 2005년에 이르기까지 연구동향에 관한 기술적 분석을 실시하였다. 둘째, 장애의 복합성에 기초한 사분모델을 이용하여 한국장애인복지학의 이론적 경향을 분석하였다. 이 연구의 결과 다음과 같이 두 가지를 제언한다. 첫째, 장애 현장의 다양한 이슈와 장애당사자의 욕구 반영, 장애종별 특수성과 장애인복지학 고유의 역사성 등 다양한 주제에 관한 장애 연구가 활성화되어 한국장애인복지학의 이론구축(theory-building)을 해야 한다. 둘째, 한국의 장애인복지학의 이론적 연구동향은 개인적-관념론이 우세하나 사회적-유물론이 증가하는 경향을 보이며, 이러한 이론적 경향성은 최근 장애인복지 현장 및 학계에서 이루어지고 있는 사회적 모델 및 자립생활 모델에 대한 논의와 맞물리는 것으로 이에 대한 좀 더 밀도 있는 학계 및 현장의 성찰이 필요하다.

• Journal of Microbiology and Biotechnology
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• 제33권6호
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• pp.707-714
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• 2023

Plant-derived insecticide-neonicotinoid insecticides (NIs) played a crucial role in the development of agriculture and food industry in recent years. Nevertheless, synthesis of these nitrogen-containing heterocyclic compounds with an effective and greener routing remains challenging especially to the notion raise of "green chemistry" and "atom economy". While bio-catalyzed methods mediated by nicotinate dehydrogenase (NDHase) then provide an alternative. The current review mainly focuses on the introduction of sources, components, structure, catalytic mechanism and applications of NDHase. Specifically, NDHase is known as nicotinic acid hydroxylase and the sources principally derived from phylum Proteobacteria. In addition, NDHase requires the participation of the electron respiratory chain system on the cell membrane. And the most important components of the electron respiratory chain are hydrogen carrier, which is mainly composed of iron-sulfur proteins (Fe-S), flavin dehydrogenase (FAD), molybdenum binding protein and cytochromes. Heterologous expression studies were hampered by the plasmid and host with high efficiency and currently only Pseudomonas entomophila L48 as well as Comamonas testosterone was successfully utilized for the expression of NDHase. Furthermore, it is speculated that the conjugate and inductive effects of the substituent group at position 3 of the substrate pyridine ring exerts a critical role in the hydroxylation reactions at position 6 concerning about the substrate molecular recognition mechanism. Finally, applications of NDHase are addressed in terms of pesticide industry and wastewater treatment. On conclusion, this critical review would not only deepen our understanding of the theory about NDHase, but also provides the guideline for future investigation of NDHase.

• 대한기계학회논문집A
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• 제41권7호
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• pp.655-663
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• 2017

ICT 기술의 발달로 로봇의 실내 활용이 증가하고 있다. 현재 이용되거나 향후 이용 범위가 증가할 수 있는 운반, 청소, 안내 로봇 등의 연구가 고도화 될 것이다. 실내 공간에서 이동 로봇 활용을 원활히 하기 위해 자기 위치 인식 문제는 가장 먼저 해결되어야 하는 중요한 연구이다. 추가적으로 이동 로봇의 위치가 인위적으로 이동되거나 예기치 못한 충돌로 인해 기존의 경로에서 이탈하였을 경우 등에서도 이동 로봇이 이런 상황을 인지하고 판단하여 목적지로 정확히 이동할 수 있는 강인한 시스템이 필요하다. 따라서 본 연구에서는 이동 로봇의 자기 위치 관련 여러 문제들을 해결하고자 실내에 설치되어 있는 다수의 CCTV 등 외부 영상 및 이를 절대 공간 좌표 변환한 정보와 더불어 이동 로봇의 엔코더 정보 등을 융합하여 강인한 위치 인식 시스템을 구현하였다. 추가로 이동 로봇 시스템에 경로 주행 알고리즘인 벡터 필드 히스토그램 기법을 적용하였고 실제 실험 수행 후 연구 결과를 확인하였다.

• 한국소음진동공학회논문집
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• 제18권10호
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• pp.997-1005
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• 2008

Linear motor stage is a useful device in precision engineering field because of its simple power transmission mechanism and accurate positioning. Even though linear motor stage shows fine positioning accuracy along travel axis, geometric dependent errors which relay on machining and assembling accuracy should be addressed to increase total positioning performances. In this paper, we suggests a cost effective yaw error compensation servo-system which is mounted on platform of the stage and nullify travel position dependent yaw error. This paper also provides a method of designing a sliding mode control which is robust to existing friction disturbance and model uncertainties. The reachability condition of slinding mode control for the yaw error compensating servo-system has been established. From some experimental results by using an experimental set-up, the sliding mode control showed its effective in disturbance rejection and its performance was superior to conventional linear controls.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.111.1-111.1
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• 2015

As an alternative way to get sophisticated nanostructures, atomic force microscopy (AFM) has been used to directly manipulate building primitives. In particular, assembly of metallic nanoparticles(NPs) can provide various structures for making various metamolecules. As far, conventionally made polygonal shaped metallic NPs showed non-uniform distribution in size and shape which limit its study of fundamental properties and practical applications. In here, we optimized conditions for deterministic manipulation of ultra-smooth and super-spherical gold nanoparticles (AuNPs) by AFM. [1] Lowered adhesion force by using platinum-iridium coated AFM tips enabled us to push super-spherical AuNPs in linear motion to pre-programmed position. As a result, uniform and reliable electric/magnetic behaviors of assembled metamolecules were achieved which showed a good agreement with simulation data. Furthermore, visualization of near field for super-spherical AuNPs was also addressed using photosensitive azo-dye polymers. Since the photosensitive azo-dye polymers can directly record the intensity of electric field, optical near field can be mapped without complicated instrumental setup. [2] By controlling embedding depth of AuNPs, we studied electric field of AuNPs in different configuration.