Degrees Tilt Research Articles

Cerebral blood velocity during concurrent supine cycling, lower body negative pressure, and head-up tilt challenges: implications for concussion rehabilitation

Introduction. The effect of concurrent head-up tilt and lower body negative pressure (LBNP) have been examined on middle cerebral artery velocity (MCAv) at rest; however, it is unknown the superimposed effect these factors have on blunting the elevation in cerebral blood velocity associated with moderate-intensity exercise. Methods. 23 healthy adults (11 females / 12 males, 20–33 years) completed three visits. The first consisted of a maximal ramp supine cycling test to identify the wattage associated with individualized maximal MCAv. Subsequent visits included randomized no LBNP (control) or LBNP at −40 Torr (experimental) with successively increasing head-up tilt stages of 0, 15, 30, and 45 degrees during the pre-described individualized wattage. Transcranial Doppler ultrasound was utilized to quantify MCAv. Two-factorial repeated measures analysis of variance with effect sizes were used to determine differences between days and tilt stages. Results. Between-day baseline values for MCAv, heart rate, and blood pressure displayed low variability with <5% variation. With no LBNP, MCAv was above baseline on average for all participants; however, 15 degrees and 30 degrees tilt with concurrent −40 Torr LBNP was sufficient to return MCAv to 100% of baseline values in females and males, respectively. Body-weight did not impact the association between tilt and pressure (R 2 range: 0.01–0.12). Conclusion. Combined LBNP and tilt were sufficient to reduce the increase in MCAv associated with moderate-intensity exercise. This exercise modality shows utility to enable individuals with a concussion to obtain the positive physiological adaptions associated with exercise while minimizing symptom exacerbation due to the notion of the Monro-Kellie doctrine.

Comparison of a 20 degree and 70 degree tilt test in adolescent myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients.

During a standard 70-degree head-up tilt test, 90% of adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develop an abnormal reduction in cerebral blood flow (CBF). A 70-degree test might not be tolerated by young ME/CFS patients because of the high incidence of syncopal spells. This study examined whether a test at 20 degrees would be sufficient to provoke important reductions in CBF in young ME/CFS patients. We analyzed 83 studies of adolescent ME/CFS patients. We assessed CBF using extracranial Doppler measurements of the internal carotid and vertebral arteries supine and during the tilt. We studied 42 adolescents during a 20 degree and 41 during a 70 degree test. At 20 degrees, no patients developed postural orthostatic tachycardia (POTS), compared to 32% at 70 degrees (p = 0.0002). The CBF reduction during the 20 degree tilt of -27(6)% was slightly less than during the reduction during a 70 degree test [-31(7)%; p = 0.003]. Seventeen adolescents had CBF measurements at both 20 and 70 degrees. The CBF reduction in these patients with both a 20 and 70 degrees test was significantly larger at 70 degrees than at 20 degrees (p < 0.0001). A 20 degree tilt in young ME/CFS patients resulted in a CBF reduction comparable to that in adult patients during a 70 degree test. The lower tilt angle provoked less POTS, emphasizing the importance of using the 70 degree angle for that diagnosis. Further study is needed to explore whether CBF measurements during tilt provide an improved standard for classifying orthostatic intolerance.

Evaluating the Accuracy of Determining Coordinates of Corners of the Building Surveyed in Tilt Technology

Integrated Inertial Measurement Unit (IMU) and electronic compass; small, sturdy form factor; supports all communications, satellites, and constellations (Revolutionary 9 axis IMU and ultra-compact 3-axis e-Compass). By integrating a 9-axis IMU with a digital compass, the Topcon Hiper Versatile Global Navigation Satellite System (VR GNSS) receiver can correct for up to 15 degrees of pole tilt. It may be now measured all the way to the edge/corner of a building without requiring an offset. The emerging technology makes up for the fact that plum field surveys can be off by up to 15 degrees. The accuracy of measured building corners is investigated in this study using Topcon Inertial Levelling Technology (TILT) in the IMU and e-Compass. The results of a case study of 5, 10, 15 degree tilt angles show that a 3D positioning accuracy of about 10 cm is achievable even when the pole is tilted.

Evaluation of Crossover Sign in Pelvis Models Made with a Three-Dimensional Printer.

Introduction Investigation of the crossover sign (COS) in different degrees of tilt in pelvises made by three-dimensional printing of CT scans among patients with normal hip versions was carried out. Methods Radiology CT scans of 8 normal pelvises reconstructed in 3D and the effect of sequential tilting on the presence of the false-positive COS in 48 radiographs were investigated. Results The COS was seen in 77% of the AP radiographs during tilt changes. The average distance between the tip of the coccyx and the symphysis pubis was 32.06 ± 10.99 mm. Also, COSs were present in all radiographs from 6 degrees tilt and above. Conclusion Minor tilting of the pelvis can result in a false-positive crossover sign on AP plain radiographs.

Performance Evaluation of 1.1 MW Grid-Connected Solar Photovoltaic Power Plant in Louisiana

In this work, performance analysis and comparison of three photovoltaic technologies are carried out in the Louisiana climate. During the calendar year of 2018, the University of Louisiana at Lafayette constructed and commissioned a 1.1 MW solar photovoltaic power plant for researching solar power in southern Louisiana and for partial energy demand of the university. It was one of the largest solar photovoltaic power plants in Louisiana when constructed and receives an annual solar insolation of 4.88 kWh/m2/d at latitude minus five degrees (25°) tilt. The solar power plant has a total of 4142 modules and incorporates three module technologies. Preliminary performance data from the system level are presented. The evaluation of different technologies is based on final yield, performance ratio, and capacity factor for one year from September 2019 to August 2020. An economic analysis is carried out using levelized cost of energy for the three photovoltaic (PV) technologies. Finally, the results are compared with simulated results of System Advisor Model (SAM) and PVsyst. It was found that copper indium gallium selenide (CIGS) has better performance ratio of 0.79 compared with monocrystalline silicon and polycrystalline silicon, which have performance ratios of 0.77 and 0.73, respectively. The simulation results correlated with the actual performance of the plant.

Cerebral Blood Flow Is Reduced in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients During Mild Orthostatic Stress Testing: An Exploratory Study at 20 Degrees of Head-Up Tilt Testing.

Introduction: In a study of 429 adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), we demonstrated that 86% had symptoms of orthostatic intolerance in daily life. Using extracranial Doppler measurements of the internal carotid and vertebral arteries during a 30-min head-up tilt to 70 degrees, 90% had an abnormal reduction in cerebral blood flow (CBF). A standard head-up tilt test of this duration might not be tolerated by the most severely affected bed-ridden ME/CFS patients. This study examined whether a shorter 15-min test at a lower 20 degree tilt angle would be sufficient to provoke reductions in cerebral blood flow in severe ME/CFS patients. Methods and results: Nineteen severe ME/CFS patients with orthostatic intolerance complaints in daily life were studied: 18 females. The mean (SD) age was 35(14) years, body surface area (BSA) was 1.8(0.2) m2 and BMI was 24.0(5.4) kg/m2. The median disease duration was 14 (IQR 5–18) years. Heart rate increased, and stroke volume index and end-tidal CO2 decreased significantly during the test (p ranging from <0.001 to <0.0001). The cardiac index decreased by 26(7)%: p < 0.0001. CBF decreased from 617(72) to 452(63) mL/min, a 27(5)% decline. All 19 severely affected ME/CFS patients met the criteria for an abnormal CBF reduction. Conclusions: Using a less demanding 20 degree tilt test for 15 min in severe ME/CFS patients resulted in a mean CBF decline of 27%. This is comparable to the mean 26% decline previously noted in less severely affected patients studied during a 30-min 70 degree head-up tilt. These observations have implications for the evaluation and treatment of severely affected individuals with ME/CFS.

Outstanding Conference Paper Award: 2019 IEEE Nuclear and Space Radiation Effects Conference

In this work, experimental results are presented on single-bit-upsets (SBU) and multiple-bit-upsets (MBU) on a 45 nm SOI SRAM. The upset cross-sections were obtained with accelerated testing using both protons and heavy ions. The proton upset cross-sections were obtained using proton energies ranging from 1 to 500 MeV and the heavy ion data were obtained using ions with effective linear energy transfer (LET) values from 0.6 to 100 . Overall, the SBU data on the 45 nm SOI SRAM showed upset cross-sections-per-bit that were very similar to the cross-sections-per-bit on a 65 nm SOI SRAM for both heavy ion and proton testing. This result continues a trend that has been observed with advanced SOI CMOS SRAMs. In contrast to the SBU data, the MBU data on the 45 nm SRAM showed significantly higher upset cross-sections relative to the 65 nm SRAM. The higher MBU cross-sections were also expected based upon the closer spacing of the nodes in adjacent cells. While the overall trends were anticipated, the major focus of the paper was to understand a diverse range of single event effects that were contributing to the measured upsets. As a function of the incident proton energy, both scattering events and direct ionization upsets were observed. The data also highlighted the unique upset results that are produced at a 90 degree tilt angle. The MBU data showed a very large dependence on the data stored in the SRAM. The data dependence was understood based upon the layout of the SRAM cells and the MBU upsets produced by strikes in common diffusion regions. A detailed analysis of the MBU data showed that almost all of the MBU events occurred in adjacent cells along the bit-lines of the array. This result is very important since the MBU events along the same bit-line will be effectively corrected by error-correctingcode (ECC) circuits. Thus, the higher overall MBU cross-sections that were observed with technology scaling are not a critical issue in SOI SRAMs that use ECC circuits. David F. Heidel received his B.S. degree in physics from Miami University in 1974, and his M.S. and Ph.D. degrees in physics from The Ohio State University in 1976 and 1980 respectively. In 1980, he joined IBM’s Research Division, at the Thomas J. Watson Research Center in Yorktown Heights, NY, working on Josephson superconducting technology. Since

Acromion morphology and its relationship with sub acromial Impingement

Background And Objectives: Shoulder pain due to Impingement syndrome is a common clinical entity. The cause of which are generally supported by typical changes in Acromion morphology on standard radiographs. We Evaluated 5 commonly used radiographic parameters of acromial morphology and assessed the association between different radiographic characteristics on the one hand and sub-acromial impingement on the other. Methods: Measurement of acromial type (Bigliani), acromial Slope (AS), acromial tilt(AT), Lateral acromial angle (LAA), and acromion index (AI) were done on standard radiographs of 100 patients with sub acromial impingement and 100 controls without sub-acromial pathology. Results: The acromial type III according to Bigliani was associated with Impingement, A statistically significant difference between controls and impingement patients was found for AS. AT of controls was significantly smaller than that of impingement patients. LAA of controls was not significantly different from that of impingement patients. AI of controls was significantly lower than of impingement patients. A good correlation was found between acromial type and AS. Interpretation And Conclusions: A low lateral acromial angle and a large lateral extension of the acromion are associated with a higher prevalence of Impingement. Type II Acromion is most common type whereas Type III is a risk factor for Impingement. Higher degrees of Acromion slope and lower degrees Tilt are found in Impingement syndrome. Keywords: Acromion, Impingement, Bigliani

Effect of Insertion of the Dish on the Behaviour of the Convective Heat Loss

The main contributing factor in analysing the performance of solar parabolic dish system (PDS) is the high amount of heat associated with the higher concentration ratio. To determine the convective heat loss from receiver in real scenario is a challenging task. Installation of these PDS in open environment also causes an escalation in the convection heat loss due to diverse wind circumstances. This work is aimed at providing quantitative insight into examine the heat loss behaviour by the insertion of the dish structure. The study is numerically performed using different wind velocities and attacking angles with constant cavity wall temperature. Free convection study was performed for ranges 0°–90° tilt angle and found s strong dependence of heat loss on the orientation of the dish. While in forced convection cases, different wind incidence angles in addition to tilt angles were examined from 1 to 20 m/s. The detailed convective heat loss patterns provided a clear picture of the effect of the dish. The convective heat loss was drastically changed due to the coupled dish–receiver flow interaction in almost all cases. As a result, the convective heat losses can be described as the function of the orientation of the dish–receiver system. However, the maximum heat loss occurs at zero degree tilt angle during forced convection irrespective of wind incidence angle Also, a critical velocity, depending upon the operating conditions of parabolic dish system, was observed to shift the flow from the mixed convection to forced convection flow.

Optimization of process parameters on friction stir welding of AA7075-T651 and AA6061 joint using response surface methodology

In this research work, dissimilar aluminium alloys of AA7075-T651 and AA6061 were friction stir butt welded by varying the FSW parameters such as tool tilt angle, tool offset and tool pin diameter by using central composite design of response surface methodology (RSM). Experiments were designed by considering three factors and five levels having 20 experimental runs. Ultimate tensile strength and microhardness were employed as responses. Desirability approach has been used to optimize the FSW parameters. Analysis of variance was employed to check the adequacy of the developed model at 95% confidence level. This study revealed that tool pin diameter and tool offset were most significant factors on deciding the tensile strength and microhardness of the joint. It was observed that the joint fabricated with 6 mm pin diameter, 0.9 mm tool offset and 3 degree tilt angle exhibited the maximum tensile strength and microhardness of 267 MPa and 121 Hv when compared to the other joints. Fractography analysis revealed that the FSW joint with maximum tensile strength shows fine dimples which indicates ductile mode of failure.

A biomechanical investigation of the retentive force of pedicle screw structures for different screw tulip designs

BackgroundPedicle screw based spinal fixation systems have been widely used for treating a variety of spinal diseases. The retentive force is an important factor that determines structural stability. The screw tulip design and the magnitude of nut tightening torque influence the retentive force. This study investigated the influences of varied tilt angles between the shaft-rod interface and varied nut tightening torques on the retentive force of the monoaxial, polyaxial, and uniplanar screws. MethodsThree types of tulip constructs were biomechanically tested. Two parameters that affect the retentive force include the tilt angle and the nut tightening torque. The retentive force was investigated by an axial gripping capacity test and axial torque gripping capacity test. FindingAmong all combinations of screw designs and tilt angles, the 12 Nm nut tightening torque offered a greater retentive force than the 8 Nm, except for monoaxial screws with a 0 degree tilt angle. For monoaxial screws, the retentive force was negatively correlated with increasing tilt angles. For polyaxial and uniplanar screws, the retentive forces remained constant with increasing tilt angles. InterpretationIn monoaxial screws, when the axis of the shaft isn't perpendicular to the axis of the rod, a gap is formed between the tulip-rod interface. This results in a decreased retentive force. In polyaxial and uniplanar screws, the contact surfaces were the same in different tilt angles, therefore, the retentive force remained constant, which was attributed to the adjustable tulips always being perpendicular to the axis of the rods.

Optimization of Casting Conditions for Semi-Solid A356 Aluminum Alloy

RSM and DOEs approach were used to optimize parameters for hypoeutectic A356 Alloy. Statistical analysis of variance (ANOVA) was adopted to identify the effects of process parameters on the performance characteristics in the inclined plate casting process of semisolid A356 alloy which are developed using the Response surface methodology (RSM) to explain the influences of two processing parameters (tilting angle and cooling length) on the performance characteristics of the Mean Particle Size (MPS) of α-Al solid phase and to obtain optimal level of the process parameters. The residuals for the particle size were found to be of significant effect on the response and the predicted regression model has extracted all available information from the experimental data. By applying regression analysis, a mathematical predictive model of the particle size was developed as a function of the inclined plate casting process parameters. In this study, the DOEs results indicated that the optimum setting was approx. (44) degree tilt angle and (42) cm cooling length with particle size (30.5) μm

Effect of friction stir welding parameters on mechanical and micro structural behaviour of AA7075-T651 and AA6061 dissimilar alloy joint

This article reports the effect of FSW tool parameters on tensile properties of the friction stir welded AA7075-T651 and AA 6061 butt joint. Aluminium is a widely used material in many engineering applications ranging from packaging material (cans, foil) to transportation (automobiles, aircraft, trucks). Nowadays titanium and composites are growing in use, most of commercial civil aircraft airframes are made from aluminium alloys. Without aluminium, civil and aviation would not be economically viable. In this work, dissimilar aluminium alloys such as AA7075-T651 alloy and AA 6061 alloy of 6mm thickness plate has been friction stir butt welded incorporating FSW tool parameters such as tool tilt, tool offset and pin diameter with central composite design (CCD) by using response surface methodology. It consists of three factors and five levels having 20 experimental runs. From this research, it is found that the joint fabricated with 6mm pin diameter, 0.9 mm tool offset and 3 degree tilt angle exhibited the acceptable tensile strength of 267 N/mm2 compared to other joints. SEM analysis on the tensile fractured surface along with dimples clearly reveals the failure due to ductile behaviour.

Could lateral tilt mattresses be the answer to pressure ulcer prevention and management?

Pressure ulcers have been part of illness for thousands of years and are not reducing in number. Traditionally, since the Crimean War, patients have been ritually repositioned every 2 hours, regardless of the individual need. Pressure ulcers occur mainly on bony prominences, and so it makes sense to reposition into the 30 degree tilt, off of bony prominences. Nevertheless, this still takes time in order to reposition on a regular basis. It is time to look at automatic repositioning, reducing nursing time, increasing patient comfort and releasing carers to provide more social support to the patients.

Effects of Retention Time in Nursery Containers and Root Pruning at Planting on Landscape Establishment and Anchorage of Three Tree Taxa

Tree lodging in landscapes during storms has been attributed to root architecture in nurseries. Objectives of this study were to evaluate influence of retention time in three progressively larger nursery containers, and root pruning at landscape planting, on establishment, anchorage, and root architecture in the first four post-planting years. All trees were retained in three progressively larger containers (11, 57, and 170 L) for a total of 32 months, with varying retention times in each. Retention time had little influence on post-planting xylem water potential for Acer rubrum and Ulmus parvifolia. There were few differences in aboveground growth among retention times. Except for Acer, retention time had a negligible influence on anchorage. Root pruning by shaving 170 L root ball periphery when planting had no impact on growth except for one post-planting year. However, root pruning invoked a dramatic reduction in circling and descending roots four years after planting caused by root deflection in the final nursery container. Although root pruning had no influence on bending stress required to winch Magnolia trunks to any degree of trunk tilt, approximately 10% more bending stress was required to winch Acer trunks up to five degrees tilt when root balls were shaved at planting.

An Experimental Insight on the Selection of the Tool Tilt Angle for Friction Stir Welding of 7075 T651 Aluminum Alloys

Objectives: To determine the optimum tool tilt angle for friction stir welding (FSW) Al 7075-T651 alloy plates by investigating the mechanical and metallurgical properties of the joints. Methods/Statistical Analysis: Al 7075-T651 plates of 6.5mm thickness are welded varying the tool tilt angle from 0 to 6 degrees. The mechanical properties like tensile strength and microhardness are evaluated. The testing of tensile specimens is done as per ASTM E8 M-04 standards. The Vickers hardness has been investigated at the weld center in the transverse direction. The microstructural changes occurring are studied with the help of metallographic inspection. Scanning electron microscopy (SEM) has been adopted to evaluate the fracture mode of the tensile specimens. Findings: An important welding parameter in FSW that influences the welding quality is the tool tilt angle. In this paper the results of Al 7075-T651 joints welded by FSW with varying tilt angle are investigated for their mechanical strength and metallurgical properties. Evaluation of the tensile strength is carried out and put in relation with the microstructure investigations. From the experimental analysis it is observed that the weld joints made with two degree tool tilt angle are defects free resulting into the best mechanical and metallurgical properties compared to other joints. The fracture surface examination with the scanning electron microscope shows that the fracture surface of the joints are largely governed by the change in the tilt angles. The observations of fracture surface under SEM shows that the joint made with two degree tilt angle failed in a ductile mode whereas all the other joints failed in brittle mode. Application/Improvements: 7000 series aluminum alloys are a family of alloys that are practically unweldable by fusion welding processes. FSW procedure can be economically utilized to weld such alloys. This study will benefit to direct the selection of tool tilt angle during FSW of Al 7075 T651 plates.

Application of gravity separators for enrichment of South Chah-Palang tungsten ore

In the present study, the possibility of concentrating tungsten-copper vein ore in South Chah-Palang was examined using gravity separators including Jig Machine (-2360+600 μm), shaking table (-600+120 μm), and multi-gravity separator (MGS) (-120 μm). The representative sample contains 1.5% WO3 and 5.95% CuO. The main tungsten minerals were ferberite and wolframite and their appropriate liberation degree was approximately in the range of 250 μm. Box-Behenken and CCD response surface methods were applied to model and optimize jig machine and MGS results, respectively. Shaking table performance was modeled by full factorial design method. In Jig machine tests, the effects of water flow rate, frequency and feed particle size were investigated. Deck inclination, wash water, and feed water flow rate were operational parameters in shaking table. In the MGS testes, the effects of two parameters of tilt angle and wash water flow rate were inspected. In this set of experiments, WO3 recovery and grade were considered as responses of each model. The maximum recovery of WO3 in jig machine was obtained in water flow rate of 3.71 lit/min, frequency of 153rpm, and the particle size range of -2360+1700 μm. In this case, the grade and recovery of WO3 were 2.85% and 94.33%, respectively. The maximum WO3 recovery was 93.9% with grade of 8.20 % using shaking table in the deck inclination of 11 degree, feed water flow rate of 7 lit/min, and wash water flow rate of 8 lit/min. The maximum WO3 recovery in MGS attained with 3.45 degrees tilt angle and wash water rate of 3.16 lit/min. The grade and recovery of WO3 in the MGS method were 4.2% and 90.61%, respectively.

Effect of Container Type and Root Pruning on Growth and Anchorage After Planting Acer rubrum L. into Landscape Soil

Acer rubrum L. ‘Florida Flame’ were grown in #3 containers of eight types, then shifted to #15 containers, then finally into #45 containers. Half the trees were root pruned by removing periphery 3 cm of root ball at each shift to larger containers. In addition to and simultaneous with being shifted into successively larger containers, some trees from each container size were planted directly into soil. Type of container and root pruning had no impact on trunk diameter, tree height, or root cross-sectional area on trees planted into soil from any container size. Type of container influenced architecture of planted root systems evaluated when all trees were five-years-old with limited impact on anchorage. Container type only impacted anchorage of trees planted from #45 containers, and impact was small. In contrast, shaving root balls during production substantially reduced imprint left by all containers evaluated when trees were five-years-old. Shaving during production also improved anchorage by 20%–25% compared to not root pruning. More roots grew on north than the south side of tree in the nursery and landscape. Bending stress increased with trunk angle and its square while winching trunks to five degrees tilt.

A Sensitivity Dosimetry Study of the Setup Uncertainties during Machine Commissioning and Annual QA

This study is to investigate three common potential setup uncertainties during Linac commissioning and annual QA and to evaluate how these uncertainties propagate into the quality of beam profiles and patient dosimetry using gamma analysis. Three uncertainty scenarios were purposely introduced for gantry position tilted from 0&ring; - 3&ring; (scenario 1), isocenter position misaligned from 0 - 6 mm (scenario 2) and SAD changed from 99.5 - 103 cm (scenario 3). A 60 × 60 × 60 cm3 water phantom cube was created to replicate a 3D water tank in VarianEclipse (V.11) treatment planning system (Varian Medical Systems, Palo Alto, CA). For each scenario, beam data profiles (crossline and diagonal) and PDD curves were calculated at different field sizes and depths for three energies: 6 MV, 6 MV-FFF and 10 MV-FFF. Gamma analysis method was used to compare a total of 263 profiles to baseline using a 1%/1mm parameter with 90% gamma passing rate criteria. For scenario 1, a ≥90% gamma passing rate and ≤1% dose difference were seen on both crossline and diagonal profiles, and PDD curves for gantry tilted up to 2&ring;. For 3&ring; degree tilt, the gamma passing rate decreased to ≤90% at depth of ≥20 cm for 6MV/6MV-FFF and depth of ≥12 cm for 10MV-FFF. For scenario 2, a ≤90% gamma passing rate and ≥1% dose difference were seen at depths from dmax to 20 cm for all energies. For depths ≥20 cm, mostly ≥90% gamma passing rate and ≤1% dose difference were seen. For scenario 3, a ≥90% gamma passing rate and ≤1% dose difference were seen on ≤4 mm isocenter misalignments for all energies. In summary, gamma analysis of the beam profiles is a very sensitive test for SAD deviation scenarios and can reveal issues of sub millimeter setup uncertainty. However, it is not as sensitive for isocenter misalignment scenarios. The test is also more sensitive for FFF beams than flattening filter beams.

測長SEMによるゲートパターン裾引きの三次元形状推定

In the semiconductor manufacturing, a critical dimension scanning electron microscope (CD-SEM) is widely used as a process monitoring tool. As design rules become finer and denser in recent years, needs for controlling three-dimensional (3D) shape in addition to one- and two-dimensional size of the pattern, such as the CD value, have risen for the process monitoring. In this paper, we propose a novel approach for estimating 3D bottom footing shape of gate patterns from two SEM images, with 5 and 10 degree tilt. Bottom footing shape can provide valuable clues for inspecting and analyzing electrical properties of semiconductor devices. The proposed method realizes a highly precise estimation by combination of existing inverse stereo matching (ISM) method with a bottom footing index, which is the width of the range where the bottom footing exists. The measured shape of ISM method is represented with a cubic spline curve and is then corrected by transformation of the curve on the basis of the pre-learning relationship between bottom footing index and curve parameters. The proposed algorithm was verified with 12 samples of gate pattern. As the results of the evaluation, the average and deviation (three sigma) of the measurement error in the part of bottom footing were 1.3nm&PlusMinus;1.0nm. The proposed method can effectively provide an accurate 3D shape and is expected to be applied to the process monitoring in actual production lines.