• Title/Summary/Keyword: Numeric solution

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Analysis of 2-D Potential Problem with L-shape Domain by p-Convergent Boundary Element Method (p-수렴 경계요소법에 의한 L-형 영역을 갖는 2차원 포텐셜 문제 해석)

  • Woo, Kwang-Sung;Jo, Jun-Hyung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.1
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    • pp.117-124
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    • 2009
  • The p-convergent boundary element method has been proposed to analyze two-dimensional potential problem on the basis of high order Legendre shape functions that have different property comparing with the shape functions in conventional boundary element method. The location of nodes corresponding to high order shape function are not defined along the boundary, called by nodeless node, similar to the p-convergent finite element method. As the order of shape function increases, the collocation point method is used to solve linear simultaneous equations. The collocation patterns of p-convergent boundary element method consist of non-symmetric hierarchial or symmetric non-hierarchical. As the order of shape function increases, the number of collocation point increases. The singular integral that appears in p-convergent boundary element has been calculated by special numeric quadrature technique and semi-analytical integration technique. The L-shape domain problem including singularity in the vicinity of reentrant comer is analyzed and the numerical results show that the relative error is smaller than $10^{-2}%$ range as compared with other results in literatures. In case of same condition, the symmetric p-collocation point pattern shows high accuracy of solution.

A Development of 3-D Numeric Model for the Confined Flow and Discharge under Sea Ground (해저 지중 피압유체의 흐름과 양수량 산출에 관한 3차원 수치모형의 개발)

  • Kim, Sang-Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.6
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    • pp.387-396
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    • 2010
  • A 3-D numeric model for the confined transient flow under sea ground have been developed. This is FDM model using Gauss-Seidel SOR (successive over-relaxation). This model shows the similar head distribution pattern to Theis analytic solution and MODFLOW simulation. The input flowrate to the aquifer and discharge of well have been compared. And it have been found that mass balance is influenced by the weight factor ${\alpha}$, i.e. fullyimplicit method (${\alpha}$=1) shows 5% error, but when ${\alpha}$ becomes to 0.5(Crank and Nicolson method) the mass balance becomes worse and the model result diverges. And the convergency of the model is not much different when $\lambda$ (over-relaxation factor)=0.8~1.5, but when $\lambda$>1.5, the model result diverges. The test-run shows that the well discharge becomes smaller when another well is near. This model can cover the isotropy$(Kx{\neq}Ky{\neq}Kz)$ and inhomogeneity, and can be used for the selection of well site, discharge calculation, and head prediction in case of the artificial recharge etc.

Micro pattern forming on the metal thin foil Using micro dieless forming system (마이크로 다이레스 성형 시스템을 이용한 금속박판소재의 마이크로 패턴 성형)

  • Lee, H.J.;Lee, H.W.;Park, J.H.;Lee, N.K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.379-382
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    • 2007
  • The MEMS (Micro Electro Mechanical Systems) process is used in a micro/nano pattern manufacturing method. This method is based on the lithography technology. But the MEMS process has some problems such as complicated process, long processing time and high production costs. Many researchers are doing research in substitute manufacturing method to work out a solution to these problems. In this paper, we apply a dieless incremental forming technology to a substitute method of MEMS process. This dieless forming technology is using in the commercial scale sheet forming such as a prototype of automobile sheet parts. 5-axes CNC (Computerized Numeric Control) method are applied in this system to get a micro-scale dieless forming results. These 5-axes system are composed of precision AC servo motor stages (4-axes) and PZT actuator (1-axis). A PZT actuator is used in a precision actuating axis because it can be operated in the nano scale stroke resolution. This micro dieless incremental forming system has the advantage of minimization in manipulating distance and working space. As equipment and tools become smaller in size, minute inertia force and high natural frequency can be obtained. Therefore, high precision forming performance can be obtained. This allows the factory to quickly provide the customer with goods because the manufacturing system and process are reduced. To construct this micro manufacturing system, many technologies are necessary such as high stiffness frame, high precision actuating part, structural analysis, high precision tools and system control. To achieve the optimal forming quality, the micro dieless forming system is designed and made with high stiffness characteristic.

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Is It Useful and Safe to Maintain the Sitting Position During Only One Minute before Position Change to the Jack-knife Position?

  • Park, Soo-Young;Park, Jong-Cook;Park, Sang-Hyun
    • The Korean Journal of Pain
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    • v.23 no.3
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    • pp.190-197
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    • 2010
  • Background: Conventional spinal saddle block is performed with the patient in a sitting position, keeping the patient sitting for between 3 to 10 min after injection of a drug. This amount of time, however, is long enough to cause prolonged postoperative urinary retention. The trend in this block is to lower the dose of local anesthetics, providing a selective segmental block; however, an optimal dose and method are needed for adequate anesthesia in variable situations. Therefore, in this study, we evaluated the question of whether only 1 min of sitting after drug injection would be sufficient and safe for minor anorectal surgery. Methods: Two hundred and sixteen patients undergoing minor anorectal surgery under spinal anesthesia remained sitting for 1 min after completion of subarachnoid administration of 1 ml of a 0.5% hyperbaric bupivacaine solution (5 mg). They were then placed in the jack-knife position. After surgery, analgesia levels were assessed using loss of cold sensation in the supine position. The next day, urination and 11-point numeric rating scale (NRS) for postoperative pain were assessed. Results: None of the patients required additional analgesics during surgical manipulation. Postoperative sensory levels were T10 [T8-T12] in patients, and no significant differences were observed between sex (P = 0.857), height (P = 0.065), obesity (P = 0.873), or age (P = 0.138). Urinary retention developed in only 7 patients (3.2%). In this group, NRS was $5.0{\pm}2.4$ (P = 0.014). Conclusions: The one-minute sitting position for spinal saddle block before the jack-knife position is a safe method for use with minor anorectal surgery and can reduce development of postoperative urinary retention.

An Empiricl Study on the Learnign of HMM-Net Classifiers Using ML/MMSE Method (ML/MMSE를 이용한 HMM-Net 분류기의 학습에 대한 실험적 고찰)

  • Kim, Sang-Woon;Shin, Seong-Hyo
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.6
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    • pp.44-51
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    • 1999
  • The HMM-Net is a neural network architecture that implements the computation of output probabilities of a hidden Markov model (HMM). The architecture is developed for the purpose of combining the discriminant power of neural networks with the time-domain modeling capability of HMMs. Criteria of maximum likehood(ML) and minimization of mean squared error(MMSE) are used for learning HMM-Net classifiers. The criterion MMSE is better than ML when initial learning condition is well established. However Ml is more useful one when the condition is incomplete[3]. Therefore we propose an efficient learning method of HMM-Net classifiers using a hybrid criterion(ML/MMSE). In the method, we begin a learning with ML in order to get a stable start-point. After then, we continue the learning with MMSE to search an optimal or near-optimal solution. Experimental results for the isolated numeric digits from /0/ to /9/, a training and testing time-series pattern set, show that the performance of the proposed method is better than the others in the respects of learning and recognition rates.

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A Case of the Advanced Non-Small Cell Lung Cancer Patient Who Showed Symptoms Improvement (항암치료 시 지속된 증상의 호전을 보인 태음인 폐암환자 치험 1례)

  • Park, So-Ra;Lee, Soo-Min;Lee, Soo-Kyung
    • Journal of Sasang Constitutional Medicine
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    • v.27 no.3
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    • pp.326-332
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    • 2015
  • Objectives The quality of life in cancer patients is important. The aim of this study is to report a case which showed symptoms improvement after treatment with modified Galgeunhaegi-tang. Methods We retrospectively reviewed the medical records. The patient's body weight and the circumference of lower extremity were measured and the subjective symptoms such as chest pain were evaluated by the NRS(Numeric Rating Scale). And the frequency of defecation was checked daily. Results The patient had received chemotherapy from March to November 2014 for 8th times. During the chemotherapy, the patient developed symptoms such as weight gain, edema of lower extremity, chest pain, headache, low back pain, and constipation. But additional evaluation and management with western medicine couldn't solve the problem. So he started to take Korean medicine. And he was transferred to our cancer center to keep continuing the treatment. After the treatment, the body weight, the lower extremity circumference and the subjective severity of chest pain, headache, low back pain were all decreased. During hospitalization at our center, the patient didn't suffer from constipation. Conclusions An elderly non-small cell lung cancer patient showed the improvement of symptoms that were continued during chemotherapy. As we can see in this case, Korean medicine can be a solution of the symptoms induced by chemotherapy, if there is no symptom improvement with western medicine.

Patients Treated with Acupuncture on Splenius Muscle and Combined Korean Medicine for Acute Dizziness Caused by Whiplash Injury: Three Case Reports (현훈을 동반한 편타성 손상 환자에 대한 판상근 아시혈 침치료 중심의 한방복합치료 치험 3례)

  • Ryu, Gwang-hyun;Ju, Ah-ra;Park, Mi-so;Choo, Won-jung;Choi, Yo-sup;Moon, Young-joo;Choi, Hyo-jung
    • The Journal of Internal Korean Medicine
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    • v.41 no.6
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    • pp.1210-1222
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    • 2020
  • Objective: The purpose of this study was to report the effect of acupuncture on the splenius muscle and the effect of combined Korean medicine treatment on acute dizziness in patients due to whiplash injury. Methods: Three patients with acute dizziness were treated with acupuncture of the splenius muscle and combined Korean medicine. A numeric rating scale (NRS) and the Korean dizziness handicap inventory (K-DHI) were checked every day from admission to discharge to confirm symptom improvements. Results: In the acute stage of dizziness caused by whiplash injury, acupuncture of the splenius muscle and combined Korean medicine improved the NRS and K-DHI scores. Conclusions: For patients with acute dizziness caused by whiplash injury, a combination of acupuncture on the splenius muscle and Korean medicine treatment may be a solution.

A New Approach to Mobile Interaction - focused on optimized button layout for mobile phone - (모바일 인터랙션을 위한 새로운 접근 -휴대폰 버튼의 최적화 배치 방법을 중심으로 -)

  • Byun, Jae-Hyung;Moon, Joon-Ki;Yang, Sung-Ho;Kim, Myung-Suk
    • Archives of design research
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    • v.18 no.2 s.60
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    • pp.165-172
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    • 2005
  • Button layout of mobile phone depends on the manufacturer and is going to be characterized in it's own way. So, there is not a standard layout except for numeric part. It is due to the lack of study on physical user interface and methodology to develop a design guideline. This study focuses on suggesting a methodology for development of button layout for mobile phone in term of physical user interface. The methodology of this study starts from scenarios of mobile phone usage. Operational sequences of 4 scenarios for 5 models are gathered based on the user manual. Proximity of each buttons is calculated according to the operational sequence. One of 5 models is selected and benchmarked by evaluating operational path. Considerations and directions are implicated to develop new solution alternatives. After evaluation of them, one of alternatives is suggested as an optimized button layout for mobile phone. This study focuses on an attempt to suggest a methodology of UI development in the matter of physical user interface, and a simple and easy way to be adopted and used at product designer level, compared to existing UI methodology for the expert.

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FIRST Survey: Fentanyl-TTS is Rational Solution to Treat Cancer Pain and Pain Assessment as a $5^{th}$ Vital Sign in Korean Cancer Patients (암성통증: 제5의 활력징후인 통증의 강도 측정 및 펜타닐 패취(듀로제식$^{(R)}$)의 통증 조절 효과)

  • Choi, Youn-Seon;Lee, June-Young;Lim, Yeun-Keun;Kim, Chul-Soo;Song, Hong-Suk;Kim, Sam-Yong;Kim, Su-Hyun;Kim, Jun-Suk
    • Journal of Hospice and Palliative Care
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    • v.7 no.2
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    • pp.238-247
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    • 2004
  • Purpose: Pain management is often needlessly suboptimal. Health care professionals are seldom trained in pain management, may not realize the importance of pain management or recognize that a patient is in pain, and may fear prescribing opioid medications. Noting that one of the problems related to health care professionals is poor assessment of pain, we studied a trend of pain severity and satisfaction with pain controls after using TTS-fentanyl in order to determine whether a regular pain assessment was effective for controlling cancer pain. Methods: We assessed the pain as a $5^{th}$ vital sign after using TTS-fentanyl in 471 hospitalized cancer patients during 4 days. The data were collected from September, 2003 to December, 2003. Pain severity was assessed by using a numeric pain intensity scale($0{\sim}10$) by ongoing pain assessment. Results: Pain assessment as a $5^{th}$ vital sign had led to reduce patient's pain scores. High degrees of satisfaction scores in both patients and doctors with TTS-fentanyl were observed. They were also negatively correlated with the pain severity. Conclusion: Regular pain assessment was effective in the management of cancer pain.

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