JaLCDOI 10.18926/47003
FullText URL mfe_36_1_091_106.pdf
Author Kanatani, Kenichi| Ohta, Naoya|
Abstract We present a theoretically optimal linear algorithm for 3-D reconstruction from point correspondences over two views. We also present a similarly constructed optimal linear algorithm for 3-D reconstruction from optical flow. We then compare the performance of the two algorithms by simulation and real-image experiments using the same data. This is the first impartial comparison ever done in the sense that the two algorithms are both optimal, extracting the information contained in the data to a maximum possible degree. We observe that the finite motion solution is always superior to the optical flow solution and conclude that the finite motion algorithm should be used for 3-D reconstruction.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-12
Volume volume36
Issue issue1
Start Page 91
End Page 106
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497029
JaLCDOI 10.18926/47002
FullText URL mfe_36_1_079_090.pdf
Author Kanatani, Kenichi|
Abstract We first present an improvement of Kanatani's subspace separation [8] for motion segmentation by newly introducing the affine space constraint. We point out that this improvement does not always fare well due to the effective noise it introduces. In order to judge which solution to adopt if different segmentations are obtained, we present two criteria: one is the standard F test; the other is model selection using the geometric AIC of Kanatani [7] and the geometric MDL of Matsunaga and Kanatani [13]. We test these criteria doing real image experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-12
Volume volume36
Issue issue1
Start Page 79
End Page 90
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497028
JaLCDOI 10.18926/fest/11499
FullText URL 010_067_074.pdf
Author Dewan Ashraf M.| Alam Md. Mahabubul| Nishigaki, Makoto|
Abstract The objective of this paper is to delineate flood prone areas and estimate damage in Greater Dhaka during the 1998 catastrophic flood using an integrated approach of GIS and remote sensing. Time series RADARSAT SAR data is acquired and used to demarcate flood boundaries for the 1998 flood event. This was accomplished by thresholding linear SAR imageries. Flood estimation demonstrated that flood areas steadily increased from early July 1998 and peaked on 25 August 1998 inundating 53% lands due to heavy monsoonal downpour and discharge from upstream points. Different thematic layers were combined with a derived flood map in order to assess flood damage for the same event. Flood damage analysis revealed that substantial damage has occurred in Greater Dhaka during the 1998 flood.
Keywords Synthetic Aperture Radar (SAR) flood delineation 1998 flood flood damage Greater Dhaka
Publication Title 岡山大学環境理工学部研究報告
Published Date 2005-02-28
Volume volume10
Issue issue1
Start Page 67
End Page 74
ISSN 1341-9099
language 英語
File Version publisher
NAID 120002313624
JaLCDOI 10.18926/46968
FullText URL mfe_37_1_011_014.pdf
Author Totsuji, Chieko| Limant, Muhammad S.| Tsuruta, Kenji| Totsuji, Hiroo|
Abstract A theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-11
Volume volume37
Issue issue1
Start Page 11
End Page 14
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015784816
JaLCDOI 10.18926/15821
FullText URL Mem_Sch_Eng_OU_17_1_81.pdf
Author Taniguchi Takeo| Kanei Toshio|
Abstract In this investigation the estimation method of the number of iterations for definite convergence condition by use of the Gauss-Seidel method applied for a set of linear equations which is obtained from the finite element analysis (or the finite difference analysis) of any rectangular area subdivided into N*M is proposed. Though the number of iterations can be obtained by using the eigenvalue of the governing equations, the proposed method does not require the eigenvalue but only the values of Nand M. Numerical experiments on this estimation method clarify that the estimated values are within the error bound of 10%.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1983-02-25
Volume volume17
Issue issue1
Start Page 81
End Page 96
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307520
JaLCDOI 10.18926/ESR/15034
Title Alternative 中国寧夏地域における日照時間から日積算日射量の推定
FullText URL 015_079_086.pdf
Author Yang, Qin| Tsukamoto, Osamu|
Abstract For the estimation of daily solar radiation from sunshine duration, observation data of Yinchuan station in Ningxia, China was used. Using a linear relationship between solar radiation and extraterrestrial radiation including relative sunshine duration and daylength, we obtained local coefficients s a =0.18, s b =0.62 from past five years data(1981-1985). Using the same method, coefficients for Guyuan region were confirmed too as a representative of south part of Ningxia province. Applying the local coefficients and calculation formula of solar radiation, we validated daily solar radiation of two years(1986-1987) of Yinchuan station and four years(1991-1994) of Guyuan station. The results showed high correlation coefficients of R2=0.94 in Yinchuan and R2=0.85 in Guyuan. Error analysis was applied using mean bias error(MBE), mean absolute bias error(MABE), root mean square error(RMSE),mean absolute percentage error(MAPE) on solar radiation of Yinchuan(1973-2006) and Guyuan(1986-2006) stations. Results showed that mean absolute bias error(MABE) was less than 13% and 17% in Yinchuan station and Guyuan station respectively. Then we have applied this method to the estimation of daily solar radiation at ‘Yongning’ station(near Yinchan) with the sunshine duration data at ‘Yongning’. The estimated values were compared with observed daily solar radiation at Yinchuan as past twelve years data(1989-2000). The results showed good linear relationship with high correlation coefficient of R2= 0.88.
Keywords Daily solar radiation Extraterrestrial radiation Relative sunshine duration Local coefficient
Publication Title Okayama University Earth Science Report
Published Date 2009-03-31
Volume volume15
Issue issue1
Start Page 79
End Page 86
ISSN 1340-7414
language 英語
Copyright Holders 岡山大学地球科学研究報告編集委員会
File Version publisher
NAID 120002307142
JaLCDOI 10.18926/fest/11569
FullText URL 005_071_079.pdf
Author Jafar Ali Mohammad| Takeshita, Yuji| Fujii, Hiroaki|
Abstract In-situ determination of fundamental hydraulic parameters like variably saturated hydraulic conductivity (K(FS)) and the matric flux potential (Φ(m)) provides a foundation from which several other unsaturated soil parameters can be estimated, namely the Alpha (α*) parameter. This Alpha parameter is the one of the components of 3D unsaturated flow in vadose zone and its value is the measure of the capillary component of unsaturated flow pattern. Here an in-situ technique, Pressure Infiltrometer is introduced to record the steady flow rate applying a constant positive head on an unsaturated soil surface. The aim of this paper is to check the shape factor of 3D flow geometry and to find out its sensitivity on other unsaturated hydraulic parameters and to find out the influence of Alpha parameters on the results of the in-situ estimation of field-saturated hydraulic conductivity.
Keywords Field-saturated hydraulic conductivity Matric flux potential Alpha parameter Shape factor In-situ test
Publication Title 岡山大学環境理工学部研究報告
Published Date 2000-02-29
Volume volume5
Issue issue1
Start Page 71
End Page 79
ISSN 1341-9099
language 英語
File Version publisher
NAID 120002313869
JaLCDOI 10.18926/15393
FullText URL Mem_Fac_Eng_OU_30_2_15.pdf
Author Oka, Hisao| Fujiwara, Shiro|
Abstract An estimation of muscle fatigue is very important study and many laboratory researchers had done actively in this field. The excellent measurement and analysis methods, however, have not established yet. The aim of this study was to investigate the muscle fatigue of low back, caused by sitting on the vehicle seat for a long time. The muscle viscoelasticity and the EMG (Electromyogram) were measured. The authors proposed the objective muscle fatigue index that was obtained from the result of PCA (Principal Component Analysis) by using the measured varlables. The objective muscle fatigue index suggests an adequate correlation with the subjective fatigue on the vehicle seat.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 15
End Page 20
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307965
JaLCDOI 10.18926/19592
FullText URL Mem_Fac_Eng_OU_31_2_29.pdf
Author Oka, Hisao| Ohshima, Masakazu|
Abstract Knee replacement arthroplasty is indicated for the patient with advanced knee pain, knee deformation, and knee functional disorder. The aim of this study was to estimate loosening after a knee replacement arthroplasty. Loosening is measured by a frequency response function, and mobility by random vibration. The modal parameters for the knee joint are obtained by applying a modal analysis to the frequency response function. The values decrease as the knee joint prosthesis loosened. These parameters serve as an index for the condition between a thighbone and the prosthesis. The various indexes will greatly clarify the stage of advance in the loosening of knee-joint prostheses.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309172
JaLCDOI 10.18926/19591
FullText URL Mem_Fac_Eng_OU_31_2_21.pdf
Author Oka, Hisao| Nakamura, Takahiko|
Abstract In evaluating the stiffness of skin surface, internal structures such as bone and muscle often affect the measurements. In the present paper, acoustic random vibration is used to estimated the viscoelasticity of a silicone-gel model. This viscoelasticity, which includes two different stiffness strata, is first estimated using a mechanical impedance spectrum, which describes the relation between the depth and viscoelasticity of internal objects. This method is applied to the depth of a silicone-gel tumor model measured by ultrasound imaging and the viscoelasticity of internal gel can be accurately estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 21
End Page 27
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309105
JaLCDOI 10.18926/46979
FullText URL mfe_37_2_045_060.pdf
Author Xu, Wei| Zhao, Y.| Horikane, T.| Hayata, T.| Tosuji, H.| Kagawa, Y.|
Abstract Resistivity distribution sounding of the non-homogeneous earth is important for electrical ground system design, geophysical prospecting and survey or monitoring the groundwater flow level. The previous paper presented that the direct inversion of the electric resistivity distribution in a domain is possible from the impedance data measured over the domain boundary using the dual reciprocity boundary element modelling in two-dimentional field [1]. The proposed inversion technique is extended to the distribution in three-dimensional space [2]. This technique is capable of inversion without iteration and meshing of the domain. Electric field with spatially varying conductivity is governed by Laplace equation, which is transformed into a Poisson-type expression with an inhomogeneous term involving the conductivity difference as a source term. Dual reciprocity method (DRM) is a technique for transforming the domain integral associated with the inhomogeneous term in Poisson equation into the boundary integral expression. The resistivity distribution in the field can thus be identified from the data observed over its boundary, for which some examples are demonstrated [2]. In this paper, the examination is extended to the case where only the data measured over the single surface is used for the inversion.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2003-03
Volume volume37
Issue issue2
Start Page 45
End Page 60
ISSN 0475-0071
language 英語
File Version publisher
NAID 80016037881
JaLCDOI 10.18926/15415
FullText URL Mem_Fac_Eng_OU_29_2_29.pdf
Author Oka, Hisao| Fukuda, Takashi|
Abstract In the stiffness evaluation from the skin surface, the body structure under the skin, like a bone and muscle, influences on the measurement results. The authors developed the measurement system of biomechanical impedance with applying a vibration of acoustic frequency onto the body surface. We measured the viscoelasticity of the silicone-gel model, which involves metal blocks, from the gel surface by using this system. The internal structure of model is estimated from the relation between the viscoelasticity and the distance from the gel surface to the internal block. Applying this method, the shape of ribs of the right chest are estimated. The shapes and viscoelasticity of silicone-gel tumor model, which has two different tumors, are also estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307199
JaLCDOI 10.18926/fest/11626
FullText URL 001_151_162.pdf
Author Ndegwa George Maina| Yomota, Atsushi|
Abstract Actual irrigation situation in a typical upland irrigation district was estimated by the water balance method during the 1993 rainy and the 1994 dry year periods. Soil moisture conditions were analysed for cases where daily district water use was supplied to all the cropped upland farms, and to reduced irrigation area percentages. Consumptive use was obtained through monthly weighted crop coefficients used to reduce penman's potential evapotranspiration. The moisture budget was examined at three levels of total readily available moisture, TRAM, i.e., 20,30 and 40 mm; the effect of upward capillary rise was also considered. The results of this study indicated that the actual moisture conditions in upland irrigated farms is influenced by irrigation area, cropping pattern, stage of crop growth and upward capillary rise in the farms. Actual irrigated area was within the range of about 44 to 100% of cropped area while upward capillary rise was between 0.1 and 1 mm day-1, TRAM level of 30 to 40 mm was considered most appropriate for the district. Monthly effective rainfall percentages from the water balance method were fairly close to that determined by the basic irrigation requirement method for some months. Basic irrigation requirement may therefore be considered to incorporate capillary water contribution.
Keywords Upland irrigation TRAM Water balance Capillary water Effective rainfall
Publication Title 岡山大学環境理工学部研究報告
Published Date 1996-03
Volume volume1
Issue issue1
Start Page 151
End Page 162
ISSN 1341-9099
language 英語
File Version publisher
NAID 120002313861
JaLCDOI 10.18926/15833
FullText URL Mem_Sch_Eng_OU_17_2_31.pdf
Author Taniguchi Takeo| Ikuta Shusaku|
Abstract New estimation method of the optimum relaxation factor for the successive overrelaxation method (SOR) is proposed, and the efficiency of the new method is surveyed through a number of numerical experiments. This method can a priori determine the value of the factor by using only the topological properties of the problem, and it is valid for a sparse set of linear equations obtained by using the five-point difference scheme for any rectangular area with arbitrary boundary conditions. The experiments clarify that the method can estimate good approximate value of the factor.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1983-06-30
Volume volume17
Issue issue2
Start Page 31
End Page 46
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307996
Author Hiura, U.| Heta, H.|
Published Date 1977-03
Publication Title 農学研究
Volume volume56
Issue issue4
Content Type Departmental Bulletin Paper
Author Nasu, Hideo| Hiura, Unji|
Published Date 1986-03
Publication Title 農学研究
Volume volume61
Issue issue2
Content Type Departmental Bulletin Paper
Author Hiura, U.|
Published Date 1965-12
Publication Title 農学研究
Volume volume51
Issue issue1-2
Content Type Departmental Bulletin Paper
Author 小沢 潤二郎| 岡本 賢一|
Published Date 1956-03
Publication Title 農学研究
Volume volume44
Issue issue1
Content Type Departmental Bulletin Paper
Author 小沢 潤二郎| 岡本 賢一|
Published Date 1956-10
Publication Title 農学研究
Volume volume44
Issue issue2
Content Type Departmental Bulletin Paper
Author 小沢 潤二郎| 岡本 賢一|
Published Date 1957-08
Publication Title 農学研究
Volume volume45
Issue issue1
Content Type Departmental Bulletin Paper