• Journal of Radiation Protection and Research
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• 제44권1호
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• pp.43-52
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• 2019

Background: The mid-term performance of clinical linear accelerator (LINAC) during volumetric modulated arc therapy (VMAT) treatment period is not performed in clinical practice and usually replaced with one-time plan quality assurance (QA). In this research we aim to monitor daily reproducibility of VMAT delivery from tracking individual leaf movement error and dosimetric error to evaluate the mid-term quality of the machine used. Materials and Methods: First, multileaf collimator (MLC) information was imported into MATLAB program to determine which of the MLC leaves in the leaf bank had the maximum RMS position error (maxRMS). We estimated where the maximum positional errors (maxPE) of the chosen leaf occur along its path length and tracked its daily variations over the entire treatment period. Secondly, picture information of dosimetric error from portal dosimetry was imported into MATLAB where representative high gamma index region (HGR) was determined as HGR with length of > 1 cm and their centers were daily tracked. Results and Discussion: The maxPEs in the brain and tongue cases were distributed broader than in other cases, but all data were found located within ${\pm}0.5mm$. From first day to last day all of five cases show the similar visual pattern of HGRs and Centers of the longest HGRs remained within ${\pm}1mm$ of that in first day. These findings prove excellent mid-term performance of the LINAC used in VMAT treatments over a full course of treatment. Conclusion: Tracking the daily location changes of leaf movement and dosimetric error can be a good indicator of predicting the daily quality like stability and reproducibility of beam delivering in VMAT treatment.

• 대한예방한의학회지
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• 제27권2호
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• pp.73-84
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• 2023

Objectives : We tried to propose the direction of Korean medicine education through the consideration of 'professionalism as a competency beyond knowledge-skill' that modern medicine should take and therefore the perspectives of the competency-based curriculum in Korean medicine education. Methods : Competency-based curriculum, professionalism education phase and competency at medical school, student demand survey, Korean medicine education Accreditation Standards, and related research articles were used. Results : Proposed development measures to cultivate students' professionalism in Korean medicine education are as follows. self-care and emotional stability programs, communications between patient and doctor and among the colleagues, career exploration programs based on global medical trends and government policy, standardized professional training programs, and the evaluation of teaching experiences and achievements. Conclusions : The main purpose of the reorganization of the competency-based curriculum should be for improving Korean medicine education. The contents of phase performance, process performance, and course performance should be carefully organized so that the core contents and spirit of traditional Korean medicine can be achieved. In modern medicine, education of professionalism has been used to cover the problems that arise from taking achievement goals only from a biomedical perspectives. Accordingly the education of professionalism is also important in Korean medicine education as the modern Korean medicine follows the aspect of modern medicine,

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.869-879
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• 1995

The new field of learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this task. The simplest forms of learning control are based on the same concept as integral control, but operating in the domain of the repetitions of the task. In the previous paper, I had studied the use of such controllers in a decentralized system, such as a robot with the controller for each link acting independently. The basic result of the paper is to show that stability of the learning controllers for all subsystems when the coupling between subsystems is turned off, assures stability of the decentralized learning in the coupled system, provided that the sample time in the digital learning controller is sufficiently short. In this paper, we present two examples. The first illustrates the effect of coupling between subsystems in the system dynamics, and the second studies the application of decentralized learning control to robot problems. The latter example illustrates the application of decentralized learning control to nonlinear systems, and also studies the effect of the coupling between subsystems introduced in the input matrix by the discretization of the system equations. The conclusion is that for sufficiently small learning gain, and sufficiently small sample time, the simple learning control law based on integral control applied to each robot axis will produce zero tracking error in spite o the dynamic coupling in the robot equations. Of course, the results of this paper have much more general application than just to the robotics tracking problem. Convergence in decentralized systems is seen to depend only on the input and output matrices, provided the sample time is suffiently small.

• 통상정보연구
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• 제16권1호
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• pp.145-161
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• 2014

21세기에는 물류운송 시스템의 정보화가 국제적으로 이루어져서 항공화물운송에서도 화물운송 통합서비스가 구현되고 있다. 본 연구에서는 항공화물운송 관리체계의 핵심적인 연구 주제인 운송관리 시스템과 고객만족과의 상관성을 전제로 Forwarder의 수익률을 중심으로 경영성과의 상관성을 규명하였다. 소규모 운송관리 품질과 고객만족의 상관성 연구에서 기존에 연구주제로 채택되지 않았던 경영성과와 고객 만족도를 측정하였다. 연구목적의 달성을 위해 포워딩 이용 무역업체들을 대상으로 항공화물 운송관리 품질, 성과, 만족 관련 조사를 통하여 실증분석을 하였다. 항공화물의 운송과정의 제 단계에서 시스템의 서비스조건 측면의 운송관리 부분을 대상으로 성과변수를 단일항목으로 한정하여 측정하였다. 분석 결과, 국내 포워더의 운송시장에서 업무행태가 소비자 집단인 무역업체들의 업무에 긍정적인 영향을 주는 것으로 확인되었으며 이는 본 연구의 전제조건과 합치된다. 운송관리 품질 구성 차원들은 수익률 평가로 측정된 성과에 직접적인 영향을 주는 것으로 평가되었다. 아울러 성과는 고객만족에 긍정적인 영향을 주는 것이 분석되었다. 즉, 소규모 운송관리 품질은 화물위탁자의 만족도에 영향을 주는 한편, 성과를 통해 고객만족에 영향을 주는 것이 확인되었다. 이러한 분석결과는 항공화물 운송관리 상의 업무행태와 고객의 만족의 관계를 경영성과 측면에서 규명하였다는 점에서 실학적 가치를 극대화 하였으며, 운송실무 측면에서 포워더의 운송관리 시스템 향상을 위한 지속적인 투자의 타당성을 확보해준다는 측면에서 의미가 있다.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.375-381
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• 2005

A rapid and specific high-performance liquid chromatographic method was developed and validated for the simultaneous determination of prostaglandin $E_{1}\;(PGE_{1})$ and prostaglandin $E_{1}$ ethyl ester $(PGE_{1}-EE)$ in hairless mouse skin homogenate. The sample treatment procedure involved deproteination and precipitation by acetonitrile. $PGE_{1}$ and $PGE_{1}-EE$ in supernatant were separated in a reversed-phase C18 column without being interfered by other components present in hairless mouse skin homogenate. 9-Anthracenecarboxylic acid was used as an internal standard. The retention times of $PGE_{1}$, 9-anthracenecarboxylic acid and $PGE_{1}-EE$ were, 4.5, 9.5 and 18.0 min, respectively. The assay showed linearity from 1 to $40\;{\mu}g/ml$ for both $PGE_{1}$ and $PGE_{1}-EE$. Precision expressed as RSD ranged from 2.3 to 14.1 % for $PGE_{1}$ and 1.6 to 11.0% for $PGE_{1}-EE$. Accuracy ranged from 100.5 to 119.6 % for $PGE_{1}$ and from 98.0 to 103.7% for $PGE_{1}-EE$. This method was employed successfully to follow the time course of concentrations of $PGE_{1}$ and $PGE_{1}-EE$ in hairless mouse skin homogenate for stability study.

• 대한감각통합치료학회지
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• 제11권2호
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• pp.1-11
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• 2013

목적 : 본 연구는 감각통합중재가 취학 전 자세조절장애 아동의 자세조절과 작업수행(놀이)에 미치는 영향을 알아보고자 하였다. 연구방법 : 대상은 2012년 대한감각통합치료학회 임상과정에 참여한 만 5세 8개월의 남아이다. 평가결과에 따라 치료목표, 치료계획을 제시하였고 11회기 동안 치료가 진행 되었으며 아동의 활동과 적응반응을 기술하였다. 각 회기별 목표를 목표성취척도(Goal Attainment Scale)를 이용해 측정하였으며 2012년 12월 재평가하였다. 결과 : 치료 후기 아동은 배와위굴곡자세를 20초 이상 유지하여 신체근위부 안정성이 향상되었고, 신체활동놀이 한 가지에 지속적으로 주의집중하여 노는 것이 향상되었다. 결론 : 본 연구를 통하여 고유-전정감각 중심의 감각통합 중재가 취학 전 자세조절장애 아동의 자세조절 향상과 함께 작업수행('신체활동놀이')에도 긍정적인 영향을 미치는 것을 알 수 있었다.

• 한국생활과학회지
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• 제15권5호
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• pp.791-802
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• 2006

The construction of athlete's tight-fitting garments by reducing the elastic knit pattern is an interesting subject, which directly influences the performance of the wearer. Therefore, relationships between the reduction rates of the men's pants pattern obtained using measurements of Size Korea 2004 and clothing fitting were explored to improve clothing comfort. Two pattern making methods were developed and the reduction rates were applied to those pants depending on the parts of human body. The four male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales during 4 consecutive days. While wearing the garments, subjects were kept four various postures including waist flexion and sitting etc by requests of the researchers. Likert type scale was used for the evaluation and 7 point indicates that it gave the best fit as tight-fitting pants. As results, differences in the length and girth between two piece pants pattern(style 1) and one piece pants pattern(style 2) were 0.0$\sim$0.3cm. Between two pattern making methods, one piece pants pattern(the style 2) was superior to two piece pants pattern in terms of subjective sensation and fit. Among eight tight-fitting pants, C, D, G, H pants were superior in terms of fitting and stability of waist and hip part to the others. ill case of tight-fitting pants, the reduction rate of the pattern in the course direction, the reduction rate of T2/3(66%) was better than that of T/2(50%), but the reduction rate of the pattern in the wale direction, that of the part of crotch, which was very sensitive part, should be kept the same as suggested earlier by Ziegert(1988).

• 대한전자공학회논문지TE
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• 제39권2호
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• pp.84-89
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• 2002

본 논문에서는 무선전화 시스템의 잡음제거 방법을 제안한다. 구현회로는 압축기(Compressor), 신장기(Expender) 및 필터로 구성된다. 제안방법의 기본개념은 채널잡음을 방지하기 위해 전송전에 음성신호를 압축(Compress)하여 전송하고 원래의 신호를 복원하기 위해 전송신호의 역 비율로 신장(Expand)한다. 압축과 신장과정을 통해서 음성신호의 감쇠나 왜곡은 일어나지 않는다. 압축과정에서 압축기의 이득은 입력신호의 유효 다이나믹 영역과 신호대 잡음 비를 향상시키기 위해 음성신호의 포락선 레벨에 따라 자동적으로 제어된다. 압축비율은 음성신호의 제곱근(Root) 배로 압축한다. 압축된 신호는 신장기에서 음성신호의 제곱이 되게 신장하여 원래의 신호를 복원한다. 시뮬레이션을 통해 제안한 방법의 성능과 안정성을 검증하였다.

• 대한토목학회논문집
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• 제9권3호
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• pp.125-131
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• 1989

도로포장(道路鋪裝)은 그 수명기간내(壽命其間內)에 다수(多數)의 반복하중(反復荷重)을 받는 데, 이 반복된 재하(재하)에 의해 영구변형(永久變形)과 피로파괴(疲勞破壞)가 발생하여, 포장(鋪裝) 공용성(供用性)이 저하(低下)된다. 따라서 높은 공용성(供用性)을 유지(維持)하려면, 포장(鋪裝)의 각부(各部)에서 이와 같은 문제(問題)의 발생(發生)을 막고, 포장(鋪裝)의 안정성(安定性)을 향상(向上)시키기 위해서는 노반(路盤), 노상(路床)에 대해서 반복재하에 따른 영구변형(永久變形)이나 피로파괴(疲勞破壞)의 문제(問題)를 해결하는 것이 중요하다. 이와 같은 관점(觀點)에서 본(本) 연구(硏究)는 $20kg/cm^2$의 7일 강도를 갖는 각각 시멘트량 92%와 18.3%인 사질토 soil-cement와 점성토 soil-cement에 있어서 반복하중(反復荷重)을 가하였을 때의 변형특성(變形特性)에 대해서 검토(檢討)하였다. 연구 결과, 사질토 soil-cement의 탄성계수는 점성토 soil-cementt 보다 크며, 반복횟수 $1{\times}10^3$회(回)까지 탄성계수가 감소하고, 그 후 $1{\times}10^5$회(回)까지는 증가하였다. 또한 일축압축강도(一軸壓縮强度)는 약 30% 정도의 강도증가(强度增加) 나타냈다.

• International Journal of Aeronautical and Space Sciences
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• 제8권1호
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• pp.10-20
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• 2007

For spacecraft attitude control, reaction wheel (RW) steering laws with more than three wheels for three-axis attitude control can be derived by using a control allocation (CA) approach.1-2 The CA technique deals with a problem of distributing a given control demand to available sets of actuators.3-4 There are many references for CA with applications to aerospace systems. For spacecraft, the control torque command for three body-fixed reference frames can be constructed by a combination of multiple wheels, usually four-wheel pyramid sets. Multi-wheel configurations can be exploited to satisfy a body-axis control torque requirement while satisfying objectives such as minimum control energy.1-2 In general, the reaction wheel steering laws determine required torque command for each wheel in the form of matrix pseudo-inverse. In general, the attitude control command is generated in the form of a feedback control. The spacecraft body angular rate measured by gyros is used to estimate angular displacement also.⁵ Combination of the body angular rate and attitude parameters such as quaternion and MRPs(Modified Rodrigues Parameters) is typically used in synthesizing the control command which should be produced by RWs.¹ The attitude sensor signals are usually corrupted by noise; gyros tend to contain errors such as drift and random noise. The attitude determination system can estimate such errors, and provide best true signals for feedback control.⁶ Even if the attitude determination system, for instance, sophisticated algorithm such as the EKF(Extended Kalman Filter) algorithm⁶, can eliminate the errors efficiently, it is quite probable that the control command still contains noise sources. The noise and/or other high frequency components in the control command would cause the wheel speed to change in an undesirable manner. The closed-loop system, governed by the feedback control law, is also directly affected by the noise due to imperfect sensor characteristics. The noise components in the sensor signal should be mitigated so that the control command is isolated from the noise effect. This can be done by adding a filter to the sensor output or preventing rapid change in the control command. Dynamic control allocation(DCA), recently studied by Härkegård, is to distribute the control command in the sense of dynamics⁴: the allocation is made over a certain time interval, not a fixed time instant. The dynamic behavior of the control command is taken into account in the course of distributing the control command. Not only the control command requirement, but also variation of the control command over a sampling interval is included in the performance criterion to be optimized. The result is a control command in the form of a finite difference equation over the given time interval.⁴ It results in a filter dynamics by taking the previous control command into account for the synthesis of current control command. Stability of the proposed dynamic control allocation (CA) approach was proved to ensure the control command is bounded at the steady-state. In this study, we extended the results presented in Ref. 4 by adding a two-step dynamic CA term in deriving the control allocation law. Also, the strict equality constraint, between the virtual and actual control inputs, is relaxed in order to construct control command with a smooth profile. The proposed DCA technique is applied to a spacecraft attitude control problem. The sensor noise and/or irregular signals, which are existent in most of spacecraft attitude sensors, can be handled effectively by the proposed approach.