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Various Pulse Forming of Pulsed $CO_2$ laser using Multi-pulse Superposition Technique

  • Chung, Hyun-Ju;Kim, Hee-Je
    • KIEE International Transactions on Electrophysics and Applications
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    • v.11C no.4
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    • pp.127-132
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    • 2001
  • We describe the pulse forming of pulsed $CO_2$laser using multi-pulse superposition technique. A various pulse length, high duty cycle pulse forming network(PFN) is constructed by time sequence. That is, this study shows a technology that makes it possible to make various pulse shapes by turning on SCRs of three PFN modules consecutively at a desirable delay time with the aid of PIC one-chip microprocessor. The power supply for this experiment consists of three PFN modules. Each PFN module uses a capacitor, a pulse forming inductor, a SCR, a High voltage pulse transformer, and a bridge rectifier on each transformer secondary. The PFN modules operate at low voltage and drive the primary of HV pulse transformer. The secondary of the transformer has a full-wave rectifier, which passes the pulse energy to the load in a continuous sequence. We investigated laser pulse shape and duration as various trigger time intervals of SCRs among three PFN modules. As a result, we can obtain laser beam with various pulse shapes and durations from about 250 $mutextrm{s}$ to 600 $mutextrm{s}$.

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Neurophysiological Evaluation of the Motor System Using Transcranial Magnetic Stimulation (뇌자기자극을 이용한 운동신경계의 신경생리학적 평가)

  • Shin, Hae-Won;Sohn, Young-H.
    • Annals of Clinical Neurophysiology
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    • v.13 no.1
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    • pp.1-12
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    • 2011
  • Transcranial magnetic stimulation (TMS) is a non-invasive tool used to study aspects of human brain physiology, including motor function and the pathophysiology of various brain disorders. A brief electric current passed through a magnetic coil produces a high-intensity magnetic field, which can excite or inhibit the cerebral cortex. Although various brain regions can be evaluated by TMS, most studies have focused on the motor cortex where motor evoked potentials (MEPs) are produced. Single-pulse and paired-pulse TMS can be used to measure the excitability of the motor cortex via various parameters, while repetitive TMS induces cortical plasticity via long-term potentiation or long-term depression-like mechanisms. Therefore, TMS is useful in the evaluation of physiological mechanisms of various neurological diseases, including movement disorders and epilepsy. In addition, it has diagnostic utility in spinal cord diseases, amyotrophic lateral sclerosis and demyelinating diseases. The therapeutic effects of repetitive TMS on stroke, Parkinson disease and focal hand dystonia are limited since the duration and clinical benefits seem to be temporary. New TMS techniques, which may improve clinical utility, are being developed to enhance clinical utilities in various neurological diseases.

PHOTOELASTIC ANALYSIS OF STRESSES INDUCED BY VARIOUS SUPERSTRUCTURES ON THE ENDOSTEAL IMPLANT (치과 임플랜트 보철 수복시 각 상부구조의 형태에 따라 발생되는 응력의 광탄성학적 분석)

  • Choi Young-Hee;Cho In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.4
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    • pp.679-686
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    • 1993
  • The osseointegrated implant conducts the stress directly to the bone due to lack of cushoning effect of periodontal ligament. So, the design and material quality of superstructure plays an important role in resolution and diffusion of stress. Recently, the various superstructures have been developed to improve esthetics and resolve various complicated conditions. The purpose of this study was to evaluate the stress induced by various system on the osseointegrated implant using UCLA abutment, EsthetiCone abutment, Anatomic abutment as well as Branemark conventional abutment. The stress distribution was evaluated by the photoelastic method which can simultaneously observe all around stress distribution. The superstructures embedded in epoxy resin specimen were loaded at various angle with a force of 15Kg to analyse the stress distribution of the fixture. The results of this study were obtained as follows : 1. Under vertical loading, the large and broad stress was distributed below the fixture in all systems. 2. The fringe order of the stress was increased in proportion to tillting the specimen. The largest stress was shown in 25 angled degree tilting case. 3. The Branemark conventional abutment showed the lowest value, and EsthetiCone abutment, Anatomic abutment and UCLA abutment showed the stress value in accending order.

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A Numerical Analysis on Mixing Performance for Various Types of Turbine Impeller in a Stirred Vessel (교반기 내 터빈 임펠러 형태에 따른 교반성능에 대한 수치해석적 연구)

  • Choi, Younguk;Choi, Jongrak;Kim, Daejoong;Hur, Nahmkeon
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.1
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    • pp.47-55
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    • 2013
  • In the present study, a numerical simulation to analyze mixing performance inside an industrial mixer was investigated for various geometry of turbine impellers. Various pitching angles and various types of turbine blades were considered in the simulation. In order to model the rotation of impeller, the Multiple Reference Frames (MRF) technique was used. For evaluation of the effect of various shapes on the mixing performance, dimensionless coefficient such as flow coefficient, circulation coefficient, power coefficient, pumping effectiveness and circulation effectiveness were used. From the results, the effect of pitching angle of a pitched turbine impeller was to give best pumping effectiveness around $30^{\circ}$ pitching angle, whereas best circulation effectiveness around $65^{\circ}$ pitching angle. Dual pitched turbine impeller showed best performance in both pumping effectiveness and circulation effectiveness among impeller types considered in the present study.

A Study on the Use of Diagram for the Process of Architecturalization (건축화 도구로서의 다이어그램에 관한 연구)

  • Kim, Jung-Ae;Kim, Dong-Jin
    • Korean Institute of Interior Design Journal
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    • v.16 no.2 s.61
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    • pp.71-78
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    • 2007
  • This study began from the idea that new materials and awareness in the modern society demand new methods in architecture and focused on diagrams as the tool many modern architects use in their process of architectural design. Therefore, the purpose is re-finding the potential of diagrams as profilerating architectural design media by examining mentions of architects about diagrams, investigating diagrams used in design process and treating comments referring to diagrams, by redefining the meaning of the contemporary architecture and of diagrams in architecture, and by grasping the various methods of use and its process. The design process using diagrams produces synthetic or reasonable process dissimilar to previous processes. Where diagrams are mainly used as tools to relate the segregated parts compressively. On the other hand reasonable process concerns reasonable design advancement to satisfy various requirements or conditions in reality, where diagrams are used as tools offering its phase in the whole structure of various information and relating steps of design each other. Dealing synthetically in the various steps of design process with the various properties originally obtained, proposing a new type of architecture by increasing thoughts and leaving the design process open-fluid, offering process and results having the same value as design process, and satisfying requirements in reality most reasonably, diagrams working in the above-mentioned design process have the potential to narrow the schism among theory, practice and criticism in contemporary architecture.

A Case Report of Various Oriental Medical Therapy in Combination with Learning Therapy on School Underachievement Child caused by ADHD (ADHD로 인한 학습부진아동 치험 1례)

  • Wy, Young-Man;Kang, Hyung-Won
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.4
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    • pp.197-209
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    • 2009
  • Objectives : Attention Deficit Hyperactivity Disorder(ADHD) is a psychiatric disorder, characterized by the primary symptoms of inattention and/or impulsivity and hyperactivity. the aim of this study is to investigate the clinical efficiency of Various Oriental Medical Therapy combinated with Learning therapy in the treatment of ADHD. Methods : This study is a clinical report of 1 ADHD child treated with Various Oriental Medical Therapy(Herb-med, acupunture, etc.) in Combination with Learning therapy. CAR(Conner's abbreviated Rating Scale), K-CBCL, ADS(ADHD Diagnostic System) were compared between before and after treatment. Results : The results show the Various Oriental Medical Therapy in Combination with Learning therapy is efficient in the treatment of ADHD. Conclusions : Various Oriental Medical therapy including herb-med, pharmacopuncture, electroacupuncture is efficient in improvement of ADHD child. also In case of combination with Learning therapy, it is more effective in child's school life and school work. therefore, it is practical useful in the treatment of ADHD.

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An Efficient Dynamic Indexing Model for Various Structure Retrievals of XML Documents (XML 문서의 다양한 구조 검색을 위한 효율적인 동적 색인 모델)

  • 신승호;손충범;강형일;유재수
    • Journal of KIISE:Databases
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    • v.31 no.1
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    • pp.48-60
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    • 2004
  • XML documents consist of elements that are basic units of information. When the structure of XML documents is changed dynamically, we need to update structure information efficiently without changing the information of the index structure for fast retrieval. In this paper, we propose a dynamic indexing model scheme that updates the index structure in real time as the structure of XML documents is changed by insertion and deletion of elements. Our dynamic indexing model consists of a structure information representation method and a dynamic index structure. The structure information representation method supports various types of structure retrievals. Our dynamic index structure processes various structural queries efficiently. We show through various experiments that our method outperforms existing ones in processing various types of queries such as content based queries, structural queries and hybrid queries.

A Scheme on Anomaly Prevention for Systems in IoT Environment (사물인터넷 환경에서 시스템에 대한 비정상행위 방지 기법)

  • Lee, Keun-Ho
    • Journal of Internet of Things and Convergence
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    • v.5 no.2
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    • pp.95-101
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    • 2019
  • Entering the era of the 4th Industrial Revolution and the Internet of Things, various services are growing rapidly, and various researches are actively underway. Among them, research on abnormal behaviors on various devices that are being used in the IoT is being conducted. In a hyper-connected society, the damage caused by one wrong device can have a serious impact on the various connected systems. In this paper, We propose a technique to cope with the problem that the threats caused by various abnormal behaviors such as anti-debugging scheme, anomalous process detection method and back door detection method on how to increase the safety of the device and how to use the device and service safely in such IoT environment.

Use of Terminal Restriction Length Polymorphism (T-RFLP) Analysis to Evaluate Uncultivable Microbial Community Structure of Soil

  • Chauhan, Puneet Singh;Shagol, Charlotte C.;Yim, Woo-Jong;Tipayno, Sherlyn C.;Kim, Chang-Gi;Sa, Tong-Min
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.1
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    • pp.127-145
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    • 2011
  • Various environmental ecosystems are valuable sources for microbial ecology studies, and their analyses using recently developed molecular ecological approaches have drawn significant attention within the scientific community. Changes in the microbial community structures due to various anthropogenic activities can be evaluated by various culture-independent methods e.g. ARISA, DGGE, SSCP, T-RFLP, clone library, pyrosequencing, etc. Direct amplification of total community DNA and amplification of most conserved region (16S rRNA) are common initial steps, followed by either fingerprinting or sequencing analysis. Fingerprinting methods are relatively quicker than sequencing analysis in evaluating the changes in the microbial community. Being an efficient, sensitive and time- and cost effective method, T-RFLP is regularly used by many researchers to access the microbial diversity. Among various fingerprinting methods T-RFLP became an important tool in studying the microbial community structure because of its sensitivity and reproducibility. In this present review, we will discuss the important developments in T-RFLP methodology to distinguish the total microbial diversity and community composition in the various ecosystems.

Numerical analysis of Consolidation Behavior under Various Drainage Conditions (배수조건에 따른 압밀 거동의 수치적 분석)

  • Oh, Sang-Ho;Cho, Wan-Jei;Yune, Chan-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1194-1199
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    • 2010
  • Systematic finite element analyses on consolidation were performed with various drainage conditions. Numerical analyses were performed using SAGE CRISP2D, a commercial numerical analysis program for the conventional geotechnical engineering practice. For the input properties of the numerical analyses, incremental loading oedometer tests were performed on reconstituted kaolinite samples. Numerical analyses were performed with various drainage conditions such as vertical, radially inward and outward drainage conditions. For the case of radially inward drainage conditions, a series of numerical analyses were performed with varying the diameter of vertical drains. As a result, the lateral deformation and void ratio variation occurred during consolidation for the radially inward or outward drainage conditions. And the variations of the lateral deformation and void ratio did not fully disappear even after the completion of the consolidation and induced the spatial variations of the soil properties. Keywords : finite element analysis of consolidation, various drainage conditions, lateral deformation, spatial variation of soil properties.

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