• 제목/요약/키워드: and Re

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Re-SSS: Rebalancing Imbalanced Data Using Safe Sample Screening

  • Shi, Hongbo;Chen, Xin;Guo, Min
    • Journal of Information Processing Systems
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    • 제17권1호
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    • pp.89-106
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    • 2021
  • Different samples can have different effects on learning support vector machine (SVM) classifiers. To rebalance an imbalanced dataset, it is reasonable to reduce non-informative samples and add informative samples for learning classifiers. Safe sample screening can identify a part of non-informative samples and retain informative samples. This study developed a resampling algorithm for Rebalancing imbalanced data using Safe Sample Screening (Re-SSS), which is composed of selecting Informative Samples (Re-SSS-IS) and rebalancing via a Weighted SMOTE (Re-SSS-WSMOTE). The Re-SSS-IS selects informative samples from the majority class, and determines a suitable regularization parameter for SVM, while the Re-SSS-WSMOTE generates informative minority samples. Both Re-SSS-IS and Re-SSS-WSMOTE are based on safe sampling screening. The experimental results show that Re-SSS can effectively improve the classification performance of imbalanced classification problems.

A Study on Re-entry Predictions of Uncontrolled Space Objects for Space Situational Awareness

  • Choi, Eun-Jung;Cho, Sungki;Lee, Deok-Jin;Kim, Siwoo;Jo, Jung Hyun
    • Journal of Astronomy and Space Sciences
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    • 제34권4호
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    • pp.289-302
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    • 2017
  • The key risk analysis technologies for the re-entry of space objects into Earth's atmosphere are divided into four categories: cataloguing and databases of the re-entry of space objects, lifetime and re-entry trajectory predictions, break-up models after re-entry and multiple debris distribution predictions, and ground impact probability models. In this study, we focused on reentry prediction, including orbital lifetime assessments, for space situational awareness systems. Re-entry predictions are very difficult and are affected by various sources of uncertainty. In particular, during uncontrolled re-entry, large spacecraft may break into several pieces of debris, and the surviving fragments can be a significant hazard for persons and properties on the ground. In recent years, specific methods and procedures have been developed to provide clear information for predicting and analyzing the re-entry of space objects and for ground-risk assessments. Representative tools include object reentry survival analysis tool (ORSAT) and debris assessment software (DAS) developed by National Aeronautics and Space Administration (NASA), spacecraft atmospheric re-entry and aerothermal break-up (SCARAB) and debris risk assessment and mitigation analysis (DRAMA) developed by European Space Agency (ESA), and semi-analytic tool for end of life analysis (STELA) developed by Centre National d'Etudes Spatiales (CNES). In this study, various surveys of existing re-entry space objects are reviewed, and an efficient re-entry prediction technique is suggested based on STELA, the life-cycle analysis tool for satellites, and DRAMA, a re-entry analysis tool. To verify the proposed method, the re-entry of the Tiangong-1 Space Lab, which is expected to re-enter Earth's atmosphere shortly, was simulated. Eventually, these results will provide a basis for space situational awareness risk analyses of the re-entry of space objects.

Appraisal of re-irradiation for the recurrent glioblastoma in the era of MGMT promotor methylation

  • Kim, Il Han
    • Radiation Oncology Journal
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    • 제37권1호
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    • pp.1-12
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    • 2019
  • Despite recent innovation in treatment techniques and subsequently improved outcomes, the majority of glioblastoma (GBL) have relapses, especially in locoregional areas. Local re-irradiation (re-RT) has been established as a feasible option for recurrent GBL of all ages with safety, tolerability, and effectiveness both in survival and quality of life regardless of fractionation schedule. To keep adverse effects under acceptable range, cumulative dose limit in equivalent dose at 2 Gy fractions by the linear-quadratic model at α/β = 2 for normal brain tissue (EQD2) with narrow margin should be observed and single/hypofractionated re-RT should be undertaken very carefully to recurrent tumor with large volume or adjacent to the brainstem. Promising outcome of re-operation (re-Op) plus re-RT (re-Op/RT) need to be validated and result from re-RT with temozolomide/bevacizumab (TMZ/BV) or new strategy is expected. Development of new-concept prognostic scoring or risk group is required to select patients properly and make use of predictive biomarkers such as O(6)-methylguanine-DNA methyltransferase (MGMT) promotor methylation that influence outcomes of re-RT, re-Op/RT, or re-RT with TMZ/BV.

폴리머 시멘트 슬러리 도장철근의 인발부착 특성 (Pullout Bond Characteristics of Polymer Cement Slurry Coated Rebars)

  • 김현기;김민호;장성주;김완기;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.117-122
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    • 2001
  • Recently, epoxy-coated re-bar used to the structure partly and put to practical use step, but not economical and appeared to the defect of deterioration of long term bond strength between concrete. The method for complement the defect of epoxy coated re-bar, study of polymer cement slurry coated re-bar started and basic properties appeared to excellent, but study of bond properties embedded in concrete specimens insufficient until now. This study attempts to examination of using possibility for bond strength of polymer cement slurry coated re-bar between concrete specimens compare to ACI Code and KS Code through pull-out test of 15cm$\times$15cm$\times$15cm specimens with polymer cement slurry coated re-bar as polymer cement ratio 50%, 100%, 150%, coating thickness 250${\mu}{\textrm}{m}$, 440${\mu}{\textrm}{m}$ and curing age. In the results of this study, the bond strength of polymer cement slurry coated re-bar compare to plain re-bar, epoxy coated re-bar decreased St/BA-modified polymer cement slurry coated re-bar, but bond strength of PA-modified polymer cement slurry coated re-bar appeared to excellent results. The bond properties of polymer cement slurry coated re-bar between concrete will be obtain more precise results according to compressive strength change of concrete and re-bar diameter size.

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RE3+원소가 첨가된 YBCO고온초전도체의 용융성장 및 초전도 특성 (Melt Textured Growth and Superconducting Properties of RE3+ Elements Doped YBCO Superconductors)

  • 김소정
    • 한국전기전자재료학회논문지
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    • 제16권3호
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    • pp.231-237
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    • 2003
  • RE(Nd, Sm) elements doped (RE/Y)$_{1.8}$B $a_{2.4}$C $u_{3.4}$$O_{7-x}$ [(RE/Y)1.8] high $T_{c}$ superconductors were directionally grown by Top Seed Melt Growth(TSMG) process in air atmosphere. The (001)melt-textured N $d_{1.8}$B $a_{2.4}$C $u_{3.4}$ $O_{7-X}$(Nd1.8) seed crystals were used for achieving the c-axis alignment large grains perpendicular to surface of the samples. The (RE/Y)1.8 SEM micrographs of the melt-textured (RE/Y)1.8 samples revealed that the nonsuperconducting (RE/Y)211 inclusions are uniformly distributed in the superconducting (RE/Y)123 matrix except the region very close to the Nd seed crystal. The microstructure and superconducting properties were investigated by XRD, SEM, TEM and SQUID magnetometer. The Melt-textured (RE/Y)1.8 samples showed an onset $T_{c}$=91K and sharp superconducting transition. Also, the magnetization value of the (RE/Y)1.8 samples were compared with those of Y1.8 sample at 77 K. 77 K. 77 K. 77 K.K.

등온열처리와 냉각에 따른 $REBa_2Cu_3O_{7-x}$ (RE=Nd, Gd, Dy) 초전도체의 상변화 (Phase transformation of $REBa_2Cu_3O_{7-x}$ (RE=Nd, Gd, Dy) Superconductor during Continuous Cooling and Isothermal Heat Treatment)

  • 오용택;신동찬;한영희;성태현;정년호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
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    • pp.42-45
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    • 2003
  • The phase transformation of $REBa_2Cu_3O_{7-x}$ (RE=Nd, Gd, Dy) was investigated using isothermal heat-treatment and continuous cooling in air. During continuous cooling, the $REBa_2Cu_3O_{7-x}$ (RE=123) superconducting phase with well-distributed $REBa_2Cu_3O_{7-x}$ (RE-211) was obtainde at a cooling rate of $0.001^{\circ}C$/s. Single phase RE-123 (Nd, Gd, Dy) was stable at $1050^{\circ}C$, $1050^{\circ}C$, and $950^{\circ}C$ during isothermal heat-treatment, respectively. Above these temperatures the RE-211 phase existed within the RE-123 grains. The RE-123, RE-211, $BaCu_2Od_2$, and CuO phases coexisted at $50^{\circ}C$ below the partial melting temperature for each respective rare-earth RE-123.

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3D 프린팅 Auxetic Re-entrant 패턴의 기울기 각도에 따른 네오프렌 복합 직물의 역학적 특성에 관한 연구 (Mechanical Properties of 3D Printed Re-entrant Pattern/Neoprene Composite Textile by Pattern Tilting Angle of Pattern)

  • 김혜림;카비르 샤흐바지;이선희
    • 한국의류학회지
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    • 제45권1호
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    • pp.106-122
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    • 2021
  • This study confirmed the mechanical properties of an auxetic re-entrant pattern prepared using 3D printing technology and its composite fabric with neoprene for the production of functional auxetic patterns/textiles for safety shoes. Samples were prepared by the tilt angle of a re-entrant pattern of 0°, 30°, 45°, 60° and 90°, and then analyzed using Poisson's ratio, bending, compression, and tensile properties. A 3D printed auxetic re-entrant pattern (3DP-RE) and its composite fabric (3DP-RE/NP) showed a negative Poisson's ratio in all tilting angles that indicated auxetic properties. The results of the bending property shown that strength of 3DP-RE/NP was 1.5 times lower than NP, but the strain improved 2.0 times. It was confirmed that the deformation of 3DP-RE/NP is possible with a low load. Each sample type of compression behavior indicated similar regardless of the tilting angles; in addition, the compression toughness of 3DP-RE/NP increased 1.2 times compared with NP. In the case of tensile properties, 3DP-RE and 3DP-RE/NP were affected by the tilting angle, samples with 90° (the opposite of load direction) showed best tensile property and toughness. 3DP-RE/NP indicated improved bending, compression, and tensile properties.

사료내 희토 첨가가 비육돈의 생산성, 혈액내 면역관련 세포수, 육질특성 및 분 중 악취방출 가스함량에 미치는 영향 (Effects of Rare Earth Supplementation on Growth Performance, Blood Immune-Related Cell Population, Meat Quality and Fecal Odor Emission Gases in Finishing Pigs)

  • 신승오;유종상;이제현;장해동;김효진;황염;진영걸;조진호;김인호
    • Journal of Animal Science and Technology
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    • 제50권4호
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    • pp.485-498
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    • 2008
  • 본 연구는 희토의 첨가가 비육돈의 생산성, 면역관련 혈액학적 지표, 육질특성 및 분내 유해가스발생 함량에 미치는 영향에 대해 알아보기 위하여 시험을 실시하였다. 3원 교잡종 비육돈 64두를 공시하였으며, 시험 개시시 체중이 65.42±1.16kg 이었고, 10주간 사양시험을 실시하였다. 시험설계는 1)Antibiotic free diet (NC), 2)NC diet+6 weeks 44ppm of tylosin/4 weeks 22ppm of tylosin(PC) 3)NC diet+100ppm of RE(RE1) 및 4)NC diet+200ppm of RE (RE2)로 4개 처리를 하여 처리당 4반복, 반복당 4두씩 완전임의 배치하였다. 사양시험 기간 동안 일당증체량, 일당사료섭취량 및 사료효율은 처리구간에 유의적인 차이가 없었다(P>0.05). 건물 및 질소 소화율은 RE2처리구가 다른 처리구와 비교하여 높게 나타났으며(P<0.05). 에너지소화율은 RE2처리구가 NC 및 RE1처리구와 비교하여 높은 소화율을 나타내었다(P<0.05). WBC 수준은 6주에서 RE1처리구가 NC 및 RE2처리구와 비교하여 높은 함량을 나타내었다(P<0.05). 배최장근의 명도를 나타내는 L*값은 희토를 첨가한 RE1 및 RE2처리구가 NC처리구와 비교하여 높게 나타났으나(P<0.05), a* 값은 PC처리구가 RE1처리구와 비교하여 유의적으로 높았다(P<0.05). 근내지방 내 지방산 조성에 있어서 total MUFA는 RE2처리구가 다른 처리구와 비교하여 높은 함량을 나타내었으며(P<0.05), total UFA는 RE2처리구가 PC처리구와 비교하여 높았다(P<0.05). 등지방 내 지방산 조성에 있어서 Total SFA는 PC처리구가 희토를 첨가한 RE1 및 RE2처리구와 비교하여 높은 함량은 나타내었다(P<0.05). Total UFA/SFA는 희토를 첨가한 RE1 및 RE2처리구가 PC처리구와 비교하여 높게 나타났다(P<0.05). 분내 유해가스 물질의 발생 함량에 있어서 암모니아(NH3)는 희토를 첨가한 RE1 및 RE2 처리구가 NC 및 PC처리구와 비교하여 낮은 함량을 나타내었다(P<0.05). 결론적으로, 본 시험의 결과 비육돈에 희토의 첨가는 영양소 소화율, 육질특성, 지방산조성 및 분내 유해가스 함량에 영향을 미치는 것으로 사료된다.

$(Sm_{0.5}RE_{0.5})Fe_{11}Ti$ 화합물의 구조 및 자기특성 (Structure and Magnetic Properties of $(Sm_{0.5}RE_{0.5})Fe_{11}Ti$ Compounds)

  • 김희태;김윤배;김창석;김택기;권혁무
    • 한국자기학회지
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    • 제3권3호
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    • pp.196-200
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    • 1993
  • $(Sm_{0.5}RE_{0.5})Fe_{11}Ti$ 화합물(RE=Ce, Pr, Nd, Sm, Gd, Tb, Dy)은 정방정(tetragonal) $ThMn_{12}$ 형 구조로 형성되며 c축을 자화용이축으로하는 일축결정자기이방성을 갖 는다. 주조한 $(Sm_{0.5}RE_{0.5})Fe_{11}Ti$ 화합물은 RE=Sm일 때 가장 높은 이방성자장 11200 kA/m(140 kOe)을 가지며, RE=Nd일 때 포화자화가 $122.3\;Am^{2}/kg$(122.3 emu/g)로 가장 크며, RE=Gd일 때 큐리온도가 $326^{\circ}C$로 가장 높다.

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Re-188-DTPA (Diethylenetriaminepentaacetic acid)의 표지와 생체내 분포 (Labeling and Biodistribution of Re-188-DTPA (Diethylenetriaminepentaaceticacid))

  • 이진;김영주;장영수;정재민;신승애;정준기;이명철;고창순;이동수
    • 대한핵의학회지
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    • 제31권4호
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    • pp.427-432
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    • 1997
  • Re-188은 반감기가 17시간이고 진단을 위한 영상화가 가능한 감마선(155keV)을 방출하며 치료용으로 적당한 베타선(2.12MeV)을 동시에 방출하여 혈관성형술 풍선에 넣어 조사하는 접촉 베타선 방출체 치료용 방사성핵종으로 유력하다. 이 연구에서는 Re-188-DTPA를 관상동맥풍선 성형술시 풍선에 주입하는 방사성 동위원소로 쓸 수 있을지 알기 위해 우선 표지법과 풍선에서 혈관내로 샜을 때의 생체내 분포를 조사하였다. Re-188과 DTPA를 표지하는 방법을 확립하였고 표지효율은 95%, 실온과 사람 혈청에서 안정하였다. 마우스의 체내분포와 랫트와 실험견에서 얻은 신장 시간방사능곡선이 Re-188-DTPA가 신장을 통해 빠르게 제거된다는 것을 밝혔다. 이러한 결과는 Re 188-DTPA를 관상동맥의 재협착을 방지하기 위해 관상동맥풍선 성형술시 풍선에 주입하는 방사성 동위원소로 사용하여도 좋음을 시사한다.

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