• 제목/요약/키워드: Alternative Selection Procedures

검색결과 21건 처리시간 0.029초

Multiple Group Testing Procedures for Analysis of High-Dimensional Genomic Data

  • Ko, Hyoseok;Kim, Kipoong;Sun, Hokeun
    • Genomics & Informatics
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    • 제14권4호
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    • pp.187-195
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    • 2016
  • In genetic association studies with high-dimensional genomic data, multiple group testing procedures are often required in order to identify disease/trait-related genes or genetic regions, where multiple genetic sites or variants are located within the same gene or genetic region. However, statistical testing procedures based on an individual test suffer from multiple testing issues such as the control of family-wise error rate and dependent tests. Moreover, detecting only a few of genes associated with a phenotype outcome among tens of thousands of genes is of main interest in genetic association studies. In this reason regularization procedures, where a phenotype outcome regresses on all genomic markers and then regression coefficients are estimated based on a penalized likelihood, have been considered as a good alternative approach to analysis of high-dimensional genomic data. But, selection performance of regularization procedures has been rarely compared with that of statistical group testing procedures. In this article, we performed extensive simulation studies where commonly used group testing procedures such as principal component analysis, Hotelling's $T^2$ test, and permutation test are compared with group lasso (least absolute selection and shrinkage operator) in terms of true positive selection. Also, we applied all methods considered in simulation studies to identify genes associated with ovarian cancer from over 20,000 genetic sites generated from Illumina Infinium HumanMethylation27K Beadchip. We found a big discrepancy of selected genes between multiple group testing procedures and group lasso.

Penalized variable selection for accelerated failure time models

  • Park, Eunyoung;Ha, Il Do
    • Communications for Statistical Applications and Methods
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    • 제25권6호
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    • pp.591-604
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    • 2018
  • The accelerated failure time (AFT) model is a linear model under the log-transformation of survival time that has been introduced as a useful alternative to the proportional hazards (PH) model. In this paper we propose variable-selection procedures of fixed effects in a parametric AFT model using penalized likelihood approaches. We use three popular penalty functions, least absolute shrinkage and selection operator (LASSO), adaptive LASSO and smoothly clipped absolute deviation (SCAD). With these procedures we can select important variables and estimate the fixed effects at the same time. The performance of the proposed method is evaluated using simulation studies, including the investigation of impact of misspecifying the assumed distribution. The proposed method is illustrated with a primary biliary cirrhosis (PBC) data set.

족관절의 인공관절 치환술 (Total Ankle Replacement Arthroplasty)

  • 성일훈;김현욱
    • 대한족부족관절학회지
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    • 제19권1호
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    • pp.1-6
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    • 2015
  • Total ankle replacement has been performed for treatment of end stage arthritis of the ankle, hopefully being an alternative to ankle arthrodesis. However, due to its high failure rates, earlier versions of ankle replacements were not regarded as successful procedures. The latest design has shown increasingly positive results. Total joint replacement of the ankle itself is still regarded as a demanding procedure and much more challenging than that of the hip and knee in many aspects. Several studies, however, have pointed out that it is becoming the viable, accepted alternative for arthrodesis with advanced implants, appropriate patient selection, and proper training experience of procedures. Compared with arthrodesis, it shows equal or better outcomes in pain relief, range of motion, and patient's satisfaction. We are attempting to review its biomechanical characteristics, implant design, indications, complications, clinical outcomes, and survival rate.

IEEE 802.11 RSSI 기반 무인비행로봇 실내측위를 위한 AP 선택 기법 (AP Selection Criteria for UAV High-precision Indoor Positioning based on IEEE 802.11 RSSI Measurement)

  • 황준규;박준구
    • 제어로봇시스템학회논문지
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    • 제20권12호
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    • pp.1204-1208
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    • 2014
  • As required performance of UAV (Unmanned Aerial Vehicle) becomes more complex and complicated, required positioning accuracy is becoming more and more higher. GPS is a reliable world wide positioning providing system. Therefore, UAV generally acquires position information from GPS. But when GPS is not available such as too weak signal or too less GPS satellites environments, UAV needs alternative positioning system such as network positioning system. RSSI (Received Signal Strength Indicator) based positioning, which is one method of network positioning technologies, determines its position using RSSI measurements containing distance information from AP (Access Point)s. In that method, a selected AP's configuration has strong and tight relationship with its positioning errors. In this paper, for, we additionally account AP's configuration information by adopting DOP (Dilution of Precision) into AP selection procedures and provide more accurate RSSI based positioning results.

KTP 레이저를 이용한 외래 기반 후두 수술의 임상적 적용 (Clinical Applications of Office-Based Laryngeal Surgery With KTP Laser)

  • 조정해
    • 대한후두음성언어의학회지
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    • 제32권3호
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    • pp.118-123
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    • 2021
  • The pulsed photoangiolytic 532-nm potassium-titanyl-phosphate (KTP) laser has emerged in recent years as an efficacious treatment modality for vocal fold lesions. It also has broadened the indications for other laryngeal laser surgery. Features of KTP laser that it is a fiber-based delivery system and its energy is selectively absorbed by oxyhemoglobin make it suitable for office-based laryngeal procedures. An office-based KTP laser surgery provides an alternative management option for benign laryngeal diseases and can be performed comfortably under flexible endoscopic guidance which is placed through the nose of a fully awake patient. Office-based laryngeal surgery with a KTP laser can alleviate the need for general anesthesia. However, there are some limitations to apply due to reduced visual precision and the fact that the vocal folds are moving during procedures. Clinicians should carefully weigh the advantages and disadvantages of office-based procedures before a treatment option is selected. Patient selection and standardized laser energy parameters may help in decreasing complications and improving the treatment results.

과학기술예측 대상기술 선정을 위한 주요 기술영역의 조사연구 (A Study on the Science and Technology Areas for the Third Technology Foresight of Korea)

  • 정근화;고대승;이정근;손석호;변도영
    • 기술혁신학회지
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    • 제5권1호
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    • pp.110-126
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    • 2002
  • This study reviews and compares the selection procedures for science and technology topics to predict mid- and long-term trends in science and technology development in Korea, Japan, and the United Kingdom. It then identifies science and technology topics and future technologies for the third science and technology foresight of Korea. In Japan and the United Kingdom, non-technological topics that reflect socioeconomic needs are also select-ed along with technological ones. This study provides the following policy implications to enhance reliability and effectiveness of the third science and technology foresight of Korea. First, selection of science and technology topics should coincide with the national goal, taking into account development trends in science and technology and socioeconomic needs. Second, the current prediction methodologies such as "delphi" do not fully consider future uncertainties in science and technology development. A scenario method is, for example, needed to present coherent pictures of alternative futures. finally, the third technology foresight should select and include topics that reflect domestic conditions and global trend in technological progress. This study suggests 117 topics for the third science and technology foresight.foresight.

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원격탐사자료의 환경영향평가 활용을 위한 기초연구 (Preliminary Study for an Application to Environmental Impact Assessment of Remote Sensing Data)

  • 문현생;김명진;강인구;방규철
    • 환경영향평가
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    • 제4권1호
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    • pp.59-64
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    • 1995
  • Environmental Impact Assesment(EIA) is composed of various procedures, such as screening, scoping, inventory survey, prediction, assessment, mitigation measure, alternative assessment, and post management. Remote sensing introduced lately begins to be applied ecosystem and land use in inventory survey and assessment of EIA. This study explains on land use classification, buffering analysis of residential area, and overlaying analysis of odor predictive data with residential area for application to EIA with remote sensing data. Residential area extracted from land use classification of remote sensing provides effectively buffering analysis of residential area in selection of landfill site with GIS. It could assess also residential effect to an offensive odor by overlaying analysis. Application methods in EIA should be enlarged to assess effectively.

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Lasers and Robots: Recent Developments in Transoral Laser and Transoral Robotic Surgery

  • Padalhin, Andrew Reyes
    • Medical Lasers
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    • 제9권2호
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    • pp.103-109
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    • 2020
  • Transoral microsurgery has come a long way as a go-to surgical intervention technique for head and neck cancers. This minimally invasive procedure had gained acceptance through comparative clinical studies against radical neck surgical procedures, radiotherapy, and chemotherapy. Laser technology has vastly improved the oncological outcomes of this procedure and brought about an appreciation of transoral laser surgery (TLM) as a mainstay for re-sectioning malignant tumors along the throat. As an established procedure, TLM has undergone several upgrades regarding the different energy devices used for cutting, ablation, and hemostasis. Continued advances in automation have eventually led to surgical robotics, resulting in the emergence of transoral robotic surgery (TORS) as a viable advanced alternative for TLM. Similarly, expansions and enhancements (image-based guidance, fluorescence spectroscopy, and advanced robotic system) have also been investigated as potential upgrades for TORS. This paper reviews a selection of publications on the significant technological advancements to TLM and TORS over the past five years.

발목 관절 전치환술에서의 연부조직 재정렬술 (Soft Tissue Balancing on Total Ankle Replacement Surgery)

  • 최성욱;김대환;강현성
    • 대한족부족관절학회지
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    • 제28권1호
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    • pp.1-7
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    • 2024
  • Despite the advances in total ankle replacement (TAR), TAR has emerged as a promising alternative to ankle arthrodesis, particularly in severe ankle arthritis. Restoring ankle stability and alignment is the most important technical consideration and the goal of TAR. Hence, additional procedures, such as soft tissue balancing and osteotomies, are often critical parts of surgical planning. This article reviews the basics of joint balancing, offering suggestions on procedure selection for ligamentous balancing and varus and valgus malalignment in TARs.

Reproductive Biotechnologies for Improvement of Buffalo: The Current Status

  • Purohit, G.N.;Duggal, G.P.;Dadarwal, D.;Kumar, Dinesh;Yadav, R.C.;Vyas, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권7호
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    • pp.1071-1086
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    • 2003
  • Reproductive biotechnologies continue to be developed for genetic improvement of both river and swamp buffalo. Although artificial insemination using frozen semen emerged some decades back, there are still considerable limitations. The major problem appears to be the lack of efficient methods for estrus detection and timely insemination. Controlled breeding experiments in the buffalo had been limited and similar to those applied in cattle. Studies on multiple ovulation and embryo transfer are essentially a replica of those in cattle, however with inherent problems such as lower number of primordial follicles on the buffalo ovary, poor fertility and seasonality of reproduction, lower population of antral follicles at all stages of the estrous cycle, poor endocrine status and a high incidence of deep atresia in ovarian follicles, the response in terms of transferable embryo recovery has remained low with 0.51 to 3.0 per donor and pregnancy rates between 15 to 30%. In vitro production of buffalo embryos is a valid alternative to recovery of embryos by superovulation. This aspect received considerable attention during the past decade, however the proportion of embryos that develops to the blastocyst stage is still around 25-30% and hence the in vitro culture procedures need substantial improvement. Embryo cryopreservation procedures for direct transfer post thaw need to be developed for bubaline embryos. Nuclear transfer and embryo cloning is a technique that has received attention in various species during recent years and can be of immense value in buffaloes as they have a low rate of embryo recoveries by both in vitro and in vivo procedures. Gender pre-selection, genome analysis, gene mapping and gene transfer are a few of the techniques that have been studied to a limited extent during recent years and are likely to be included in future studies on buffaloes. Very recently, reproductive biotechnologies have been applied to feral buffaloes as well, but the results obtained so far are modest. When fully exploited they can play an important role in the preservation of endangered species.