• 제목/요약/키워드: Root finding

검색결과 183건 처리시간 0.023초

눈에 띄는 흉의 생성 없는 내안각췌피 교정술 (Correction of the Epicanthal Fold with Invisible Scar)

  • 이윤호;이시우;백롱민
    • Archives of Plastic Surgery
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    • 제32권3호
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    • pp.299-303
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    • 2005
  • The epicanthal fold is common natural finding in Asian eyes. It is very common that patients, who look for oriental blephaloplasty for double eye lid, request correction epicanthal fold. It is very often difficult to achieve satisfactory results if the correction of the epicanthal fold is not corrected concomitantly. Many authors described surgical procedures for correction of epicanthal folds. But most of them leave additional scars which tend to be hypertrophic and noriceable. We achieved satisfactory result in epicanthoplasty with invisible scar, using combination of procedures, such as upward incision, double eyelid operation, anchoring suture of the medial upper lid skin to the medial canthal tendon, trans-nasal root subcutaneous mattress suture of the epicanthal fold itself and combined rhinoplasty. For past six years (1998 to 2003) 17 patients have been operated with one of these mentioned procedures. The mean follow up was 4months (2weeks to 6months). All patients were satisfied and no major complication was noted. This method can be one of the effective procedures for correcting the Asian epicanthal fold for avoiding potential visible scar and ancillary procedure in double eye lid blephaloplasty.

경추간공 경막외 조영술의 양상에 관한 분석 (An Analysis of Pattern of Transforaminal Epidurography)

  • 홍지희
    • The Korean Journal of Pain
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    • 제19권2호
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    • pp.175-180
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    • 2006
  • Background: A transforaminal epidural steroid injection has been used for the treatment of radicular arm or leg pain, which has the advantage of ventral epidural spreading compared to either an interlaminar or caudal approach. However, several factors are known to affect the epidural spread pattern of contrast dye; therefore, the injected medication can not be delivered to the target site. The objective of our study was to observe any differences in the contrast flow patterns according to several factors. Methods: A total of 34 epidurographies in 29 patients, who underwent fluoroscopically guided transforaminal epidural steroid injections, were evaluated. After confirming the location of the needle tip within the anterior superior aspect of the neural foramen in the lateral view, and at the 6 o'clock position to the pedicle in the anteroposterior view, 2 ml of contrast dye was injected. The contrast flow patterns of ventral, ventral and dorsal, and dorsal epidural filling were analyzed, according to age, gender, magnetic resonance imaging finding and history of previous back surgery. Results: Ventral contrast flow occurred in 30 out of the 34 epidurographies (88%). Both ventral and dorsal contrast flow patterns were observed 13 out of 16 (81%) patients in the older age group. Also, both ventral and dorsal contrast flow patterns were observed in 16 out of 18 (88%) patients with spinal stenosis. Conclusions: Transforaminal epidural steroid injections, performed uner fluoroscopy, provide excellent nerve root filling and ventral epidural spreading. Patients with spinal stenosis or an old age have both ventral and dorsal epidural spreading patterns.

Evolution of Automatic Ordering System in Retail Market : Analyzing Inventory Data

  • Paik, SiHyun;Frazier, DeWayne P.;Mark, Isenhoff
    • International Journal of Advanced Culture Technology
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    • 제3권2호
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    • pp.1-14
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    • 2015
  • The purpose of this paper is to reveal two problems in the existing inventory systems in retail market, and to suggest a Two-Bin System under Automatic Ordering System considering only base-stock. Large retailers already have a sophisticated inventory system based on an automatic ordering principle. However, why does the out-of-stock (OOS) happen in large discount stores in spite of having a good inventory system? This paper suggests two systems after finding the root causes concerning the previous question. For evaluating the performance of each system, the random 200 data set in each sample group was generated from MINITAB 16 and obeyed the Poisson distribution. The existing inventory system in retail market cannot help generating OOS due to indwelling contradiction in itself. The reasons are the ordering deadline and the relationship between ordering quantity and base stock. This paper also demonstrates that these previous studies on inventory fall into the closed loop. Also the paper shows that the performance of the replenishment policy was better than traditional methods dealing with ordering quantity and base stock.

FRACAS에 기반한 군 무기체계의 고장분석 워크플로우 구축에 대한 연구 (A Study on the Development of FRACAS-based Failure Analysis Workflow for Military weapon system)

  • 이민영;김완걸;김경수
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제10권2호
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    • pp.93-105
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    • 2010
  • The following thesis provides an explanation for the definition of the MIL-HDBK-2155 : Failure Reporting, Analysis and Corrective Action System (FRACAS), which systemizes the collection and analysis of failure data and the feedback process of the results. It also presents a plan based on MIL-HDBK-2155 for the collection and analysis of operating specifications on weapon systems. The collection and analysis of failure data and the feedback process utilizing FRACAS contributes to identifying improvement requirements during equipment operation as well as finding and eliminating the root cause of the failures. The objective of applying FRACAS to weapon systems is to receive source data feedback for reliability enhancements and performance improvements during operation. This is done by recognizing weaknesses in the design or operation by identifying the type of failures that might occur, and by performing Failure Modes, Effects and Criticality Analysis(FMECA) and Failure Tree Analysis(FTA).

작업지연원인 기반 작업여건분석 체계 (Cause of Schedule delay-based Constraints Analysis Process)

  • 송지원;유정호;김창덕
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2007년도 정기학술발표대회 논문집
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    • pp.637-642
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    • 2007
  • 건설공사 한 프로젝트의 전체공기는 개별 작업들이 수행된 날짜의 합이라 할 수 있다. 개별 작업들에서 지연이 발생할 경우 전체 공기 또한 늦어지기 마련이다. 이러한 개별 작업의 계획상에서 작업이 수행될 확률을 높인다면 프로젝트의 공기달성 확률 또한 높아지게 될 것이다. 따라서, 계획상의 작업 실행여부 확인을 위하여 건설 생산프로세스에서 각 작업의 수행을 저해하는 제약요인을 도출하여 작업여건분석을 한다. 작업여건분석을 통해 저해요인 사전 제거와 작업간의 상호의존성을 파악으로 작성된 개별 작업계획들의 실행 가능성 확임함으로써 공사전체의 공기지연을 방지하는 체계를 구축하고자 한다.

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시설청소년을 위한 자립준비교육프로그램의 효과에 관한 연구 -사회적응 및 건강가정형성교육을 중심으로 - (A Study on Effect of Readiness Education for Independent Living of Adolescents in Residental care - Centering Around Social Adaptation and healthy Family Formation -)

  • 강복정
    • 대한가정학회지
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    • 제40권10호
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    • pp.33-48
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    • 2002
  • The purpose of this study guides them to the needs of leave preparation and material methods for self- examination and social adaptation so that they may live their remaining time in residental care better, and that execute preliminary training to improve their qualities for healthy family lives in the future. The program of this study was tested on 8 adolescents at their high school ages selected from an orphanage in Seoul. The effect of the program was determined by the quantity evaluation with a statistical analysis(ANCOVA) and also by the quality evaluation that requires interviews. Here is the summary of the result of leave preparation program; Firstly, the leave preparation program was effective on finding self-identity, psychological welfare and personal relationship. Secondly, The program helped them recognize that their own personalities, growing-up circumstances and family in root influenced on their self-understanding and growth. Most of the subjects said they accepted these factors in an affirmative way. Thirdly, the program gave a positive effect on their views of social adaptation and family formation after leave.

Feldstein-Horioka Puzzle in Thailand and China: Evidence from the ARDL Bounds Testing

  • RUANKHAM, Warawut;PONGPRUTTIKUL, Phoommhiphat
    • The Journal of Asian Finance, Economics and Business
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    • 제8권9호
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    • pp.1-9
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    • 2021
  • This study aimed to investigate the existence of the Feldstein-Horioka (1980) puzzle in international macroeconomics by applying the conditional Autoregressive Distributed Lag (ARDL) model to examine the long-run relationship between national savings and investments in Thailand and China. The input of this study relied on annual national savings and investments as a fraction of GDP during 1980-2019 which was collected from China National Bureau of Statistics (NBS) and Thailand National Economic and Social Development Council (NESDC). Hypothetically, Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root tests were applied to test the stationary properties and to investigate the integration level of selected time series. The empirical results, confirmed by cumulative sum (CUSUM) and cumulative sum square (CUSUMSQ), maintained no serial correlation and structural break problems. The finding of this study suggested that the Feldstein-Horioka puzzle in Thailand did not exist significantly. Thailand's national savings and investments nexus was independent, following the classic economic idea that financial liberalization, or perfect capital mobility, allowed national savings and investments to flow freely to countries with better interest rates. Whereas, a strong significant correlation was found in the case of China during the fixed exchange rate regime switching in 1994 and post WTO participation after 2001-2019.

Evaluating the asymmetric effects of nuclear energy on carbon emissions in Pakistan

  • Majeed, Muhammad Tariq;Ozturk, Ilhan;Samreen, Isma;Luni, Tania
    • Nuclear Engineering and Technology
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    • 제54권5호
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    • pp.1664-1673
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    • 2022
  • Achieving sustainable development requires an increasing share of green technologies. World energy demand is expected to rise significantly especially in developing economies. The increasing energy demands will be entertained with conventional energy sources at the cost of higher emissions unless eco-friendly technologies are used. This study examines the asymmetric effects of nuclear energy on carbon emissions for Pakistan from 1974 to 2019. Augmented Dickey-Fuller (ADF) and Phillips Perron (PP) unit root tests suggest that variables are integrated of order one and bound test of Autoregressive Distributed Lag (ARDL) and nonlinear ARDL confirm a long-run relationship among selected variables. The ARDL, Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS) results show that the coefficient of nuclear energy has a negative and significant impact on emissions in both short and long run. Further, the NARDL finding shows that there exists an asymmetric long-run association between nuclear energy and CO2 emissions. The vector error correction method (VECM) results indicate that there exists a bidirectional causal relationship between nuclear energy and carbon emissions in both the short and long run. Additionally, the impact of nuclear energy on ecological footprint has been examined and our findings remain robust.

Davidenko법에 의한 시간최적 제어문제의 수치해석해 (The Numerical Solution of Time-Optimal Control Problems by Davidenoko's Method)

  • 윤중선
    • 한국정밀공학회지
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    • 제12권5호
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    • pp.57-68
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    • 1995
  • A general procedure for the numerical solution of coupled, nonlinear, differential two-point boundary-value problems, solutions of which are crucial to the controller design, has been developed and demonstrated. A fixed-end-points, free-terminal-time, optimal-control problem, which is derived from Pontryagin's Maximum Principle, is solved by an extension of Davidenko's method, a differential form of Newton's method, for algebraic root finding. By a discretization process like finite differences, the differential equations are converted to a nonlinear algebraic system. Davidenko's method reconverts this into a pseudo-time-dependent set of implicitly coupled ODEs suitable for solution by modern, high-performance solvers. Another important advantage of Davidenko's method related to the time-optimal problem is that the terminal time can be computed by treating this unkown as an additional variable and sup- plying the Hamiltonian at the terminal time as an additional equation. Davidenko's method uas used to produce optimal trajectories of a single-degree-of-freedom problem. This numerical method provides switching times for open-loop control, minimized terminal time and optimal input torque sequences. This numerical technique could easily be adapted to the multi-point boundary-value problems.

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Runoff Prediction from Machine Learning Models Coupled with Empirical Mode Decomposition: A case Study of the Grand River Basin in Canada

  • Parisouj, Peiman;Jun, Changhyun;Nezhad, Somayeh Moghimi;Narimani, Roya
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.136-136
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    • 2022
  • This study investigates the possibility of coupling empirical mode decomposition (EMD) for runoff prediction from machine learning (ML) models. Here, support vector regression (SVR) and convolutional neural network (CNN) were considered for ML algorithms. Precipitation (P), minimum temperature (Tmin), maximum temperature (Tmax) and their intrinsic mode functions (IMF) values were used for input variables at a monthly scale from Jan. 1973 to Dec. 2020 in the Grand river basin, Canada. The support vector machine-recursive feature elimination (SVM-RFE) technique was applied for finding the best combination of predictors among input variables. The results show that the proposed method outperformed the individual performance of SVR and CNN during the training and testing periods in the study area. According to the correlation coefficient (R), the EMD-SVR model outperformed the EMD-CNN model in both training and testing even though the CNN indicated a better performance than the SVR before using IMF values. The EMD-SVR model showed higher improvement in R value (38.7%) than that from the EMD-CNN model (7.1%). It should be noted that the coupled models of EMD-SVR and EMD-CNN represented much higher accuracy in runoff prediction with respect to the considered evaluation indicators, including root mean square error (RMSE) and R values.

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