The geometry of joints has a significant influence on the mechanical properties of rocks.To simplify the curved joint shapes in rocks,the joint shape is usually treated as straight lines or planes in most laboratory e...The geometry of joints has a significant influence on the mechanical properties of rocks.To simplify the curved joint shapes in rocks,the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations.In this study,the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample,respectively.To describe the joint geometry,the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models.For comparison tests,the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method.The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints.The presence of joints reduces the uniaxial compressive strength (UCS),elastic modulus,and released acoustic emission (AE) energy of rocks by 37%–67%,21%–24%,and 52%–90%,respectively.Compared to the simplified joint sample,the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints.The UCS,accumulative released AE energy,and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample.The UCS value of the simplified joint sample (i.e.38.5 MPa) is much lower than that of the CT-based sample (i.e.72.3 MPa).Additionally,the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample.CT scanning provides a reliable means to visualize the joints in rocks,which can be used to verify the reliability of photogrammetry techniques.The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.展开更多
目的比较简明精神分裂症认知评估测验(Brief Assessment of Cognition in Schizophrenia,BACS)的计算机与手册式版本对精神分裂症患者认知功能评定的结果。方法60例符合DSM-IV诊断标准的精神分裂症患者分为两组,30例先接受计算机BACS测...目的比较简明精神分裂症认知评估测验(Brief Assessment of Cognition in Schizophrenia,BACS)的计算机与手册式版本对精神分裂症患者认知功能评定的结果。方法60例符合DSM-IV诊断标准的精神分裂症患者分为两组,30例先接受计算机BACS测验,4周后接受手册式BACS测验;另30例先接受手册式测验,4周后接受计算机测验。然后将两组数据交叉合并,采用配对t检验,比较计算机及手册式版本BACS的结果有无差异。结果在BACS中7项分测验中,除代币运动(TM)为手工操作外,其它分测验涉及计算机与手册式施测的不同,包括符号编码(SC)、言语记忆(VM)、数字序列(DS)、语义流畅性(CF)、字词流畅性(WF)、伦敦塔(TL)。这些分测验的比较t值分别为-0.339(P=0.736)、-1.901(P=0.062)、-1.549(P=0.127)、0.807(P=0.423)、0.121(P=0.904)、-2.744(P=0.008),两种版本的5项分测验之间无统计学意义,仅有伦敦塔具有差异性。结论BACS的计算机与手册式版本之间总体上无显著性差异,因此,可以认为BACS计算机化版本是基本成功的,改进后可以推广使用。展开更多
RompecPC is a computerized program designed to create and assemble jigsaw puzzles. The program automatically records the solver’s responses as the number of pieces positioned correctly, the number of correct and inco...RompecPC is a computerized program designed to create and assemble jigsaw puzzles. The program automatically records the solver’s responses as the number of pieces positioned correctly, the number of correct and incorrect movements, the number of times that she/he attempts to move a piece to the same place (perseverations), and the latency and place to which each piece is moved or attempted to be moved. These features facilitate the implementation and evaluation of puzzles while also reducing human error. Therefore, RompePC is a useful tool for the neuropsychological assessment of visuospatial skills in both clinical and experimental research.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42277150,41977219)Henan Provincial Science and Technology Research Project(Grant No.222102320271).
文摘The geometry of joints has a significant influence on the mechanical properties of rocks.To simplify the curved joint shapes in rocks,the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations.In this study,the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample,respectively.To describe the joint geometry,the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models.For comparison tests,the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method.The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints.The presence of joints reduces the uniaxial compressive strength (UCS),elastic modulus,and released acoustic emission (AE) energy of rocks by 37%–67%,21%–24%,and 52%–90%,respectively.Compared to the simplified joint sample,the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints.The UCS,accumulative released AE energy,and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample.The UCS value of the simplified joint sample (i.e.38.5 MPa) is much lower than that of the CT-based sample (i.e.72.3 MPa).Additionally,the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample.CT scanning provides a reliable means to visualize the joints in rocks,which can be used to verify the reliability of photogrammetry techniques.The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.
文摘目的比较简明精神分裂症认知评估测验(Brief Assessment of Cognition in Schizophrenia,BACS)的计算机与手册式版本对精神分裂症患者认知功能评定的结果。方法60例符合DSM-IV诊断标准的精神分裂症患者分为两组,30例先接受计算机BACS测验,4周后接受手册式BACS测验;另30例先接受手册式测验,4周后接受计算机测验。然后将两组数据交叉合并,采用配对t检验,比较计算机及手册式版本BACS的结果有无差异。结果在BACS中7项分测验中,除代币运动(TM)为手工操作外,其它分测验涉及计算机与手册式施测的不同,包括符号编码(SC)、言语记忆(VM)、数字序列(DS)、语义流畅性(CF)、字词流畅性(WF)、伦敦塔(TL)。这些分测验的比较t值分别为-0.339(P=0.736)、-1.901(P=0.062)、-1.549(P=0.127)、0.807(P=0.423)、0.121(P=0.904)、-2.744(P=0.008),两种版本的5项分测验之间无统计学意义,仅有伦敦塔具有差异性。结论BACS的计算机与手册式版本之间总体上无显著性差异,因此,可以认为BACS计算机化版本是基本成功的,改进后可以推广使用。
文摘RompecPC is a computerized program designed to create and assemble jigsaw puzzles. The program automatically records the solver’s responses as the number of pieces positioned correctly, the number of correct and incorrect movements, the number of times that she/he attempts to move a piece to the same place (perseverations), and the latency and place to which each piece is moved or attempted to be moved. These features facilitate the implementation and evaluation of puzzles while also reducing human error. Therefore, RompePC is a useful tool for the neuropsychological assessment of visuospatial skills in both clinical and experimental research.
