Strike Target Research Articles

Based on the Second-stage Detection Networks to Realize Accurate Detection and Recognition For Anti-ship Missiles

The target detection and recognition technology based on deep learning has high accuracy and speed of target recognition, which is a feasible way to realize the precise strike of anti-ship missiles and the essential way for the development of intelligent combat. Based on the development background of anti-ship missile precision strike and second-stage target detection networks, this paper proposed to achieve accurate detection and recognition of ship targets through Faster R-CNN network, and suggested to achieve maritime multi-targets through Mask R-CNN network. The detection method explored and find a feasible way to achieve the precise strike of anti-ship missiles.

Arm abduction angle at ball release influences shoulder forces and torques during the windmill softball pitch

Objectives:Shoulder pain and ligamentous injury is a common complaint among fast pitch softball pitchers. In addition to extreme shoulder joint motion during pitch delivery, sudden deceleration immediately after ball release places increased stress across the shoulder joint. Some pitchers release the ball with the throwing arm tucked close to the trunk, while others let the arm float outwards in a more abducted position. The position of the arm at ball release (BR) may be key to the mechanism of shoulder pain. Previous work demonstrated that during the change up pitch, softball pitchers with upper extremity pain demonstrated greater shoulder abduction at stride and less trunk lateral flexion at BR compared to athletes without pain (Oliver et al 2018). The purpose of this study was to test the hypothesis that placement of the arm closer to the trunk (shoulder adduction) at ball release will produce less shoulder stress during fastball windmill pitches.Methods:Twenty-six female fast pitch softball pitchers with a mean age of 18 +/- 6 y, including 16 high school, 7 collegiate, and 3 professional athletes, underwent 3D biomechanical pitch analyses using 20 Vicon high-speed motion capture cameras (240 hz). All pitchers threw the standard 13.11 m mound-to-plate distance at a strike zone target while a radar gun collected pitch speeds. The fastest, most accurate fastball pitches for each subject were selected for analyses (average of 5 pitches per subject). A total of 103 pitches were used to calculate: shoulder abduction angle and shoulder compression force during the BR phase (10 frames surrounding BR) and peak shoulder torques. Pearson correlations were performed to determine the relationship of shoulder frontal plane (adduction/abduction) angle during the ball release phase to these biomechanical measures.Results:The smallest abduction shoulder angle reached during the BR phase (avg: 14.06 +/- 6.71 degrees) demonstrated a significant positive correlation with shoulder compression force, p=0.008 and with peak flexion torque, p< 0.001 (Table 1). This shoulder abduction angle during the BR phase demonstrated negative correlations with peak shoulder adduction torque, p<0.001 and shoulder internal rotation torque, p< 0.001.Conclusion:These initial findings support the hypothesis that pitchers who release the ball with their arm close to their trunk demonstrate lower shoulder compression forces and shoulder flexion torques than those with a more abducted arm position. Future studies are needed to explore the interplay of pitching technique mechanics, shoulder joint stresses, and injury history to inform pitching instruction and injury prevention efforts.Table 1.The relationship between shoulder frontal plane angle during ball release with shoulder compression force and torquesMeasureAverage SDRPBall release phase peak shoulder compression force7.791.53 BW0.258*0.008Peak shoulder internal rotation torque-27.4528.65 Nm-0.377*P < 0.001Peak shoulder adduction torque-47.8649.59 Nm-0.479*P < 0.001Peak shoulder flexion torque60.7946.01 Nm0.530*P < 0.001*Established level of significance p<0.05

High precision strike point control to support experiments in the DIII-D small angle slot divertor

Improvements in strike point control enabled tests with the new small angle slot (SAS) divertor installed at DIII-D with precision as tight as ±1 mm, barring brief perturbations from ELMs. Aside from being narrower than previous baffle structures in DIII-D, simulations indicate that performance of the SAS divertor should be very sensitive to strike point position, making the improved strike point control essential for experiments with the SAS divertor. Improved control entails regulating more divertor geometry target locations than before and setting higher gain on the strike point target. This is achieved by tasking more poloidal field (PF) shaping coils with divertor topology control, fine tuning of the coil configuration and algorithm gains, and adding regulation of the power supply common rail. The result is that although more variables are controlled, precision is better: high frequency jitter in the strike point position is lower on average compared to related discharges with standard divertor shape control.

Our survey says... [mapping the built environment

Maps, apart from helping travellers, could also be powerful weapons. All maps in the Soviet Union carried deliberate errors to mislead mysterious Western spies with purposeful paranoia-driven deviations. There were no mistakes - deliberate or otherwise - in the Soviet cartographers' military maps of the West; the Maps of the 20th century exhibition in the British Library holds a 1980s map of Brighton as a possible nuclear strike target, describing every single dwelling, warehouse and workshop in minute detail.

Application of Topsis Method in Target Value Assessment of Infantry Division Joint Fire Strike

According to the characteristics of infantry division joint firepower strike target value, the topsis method is adopted to analyze the target value and establish the target value analysis index system of joint fire strike. It provided a new approach to evaluate target value of joint fire strike infantry division.

Shoulder and Scapular Kinematics during the Windmill Softball Pitch

Objectives:Pitch count has been studied extensively in the overhand throwing athlete. However, pitch count and fatigue have not been systematically evaluated in the female windmill (underhand) throwing athlete. Direct kinematic measurements of the glenohumeral and scapulo-thoracic joint have not to be correlated and determined. The purpose is to measure scapular kinematics for the high school female windmill softball pitcher and identify kinematic adaptions and changes in pitching performance due to fatigue.Methods:Eight female high school softball pitchers without previous shoulder injury were enrolled. Three-dimensional (3D) motion of the humerus, scapula and trunk were recorded with surface markers at 250 Hz. Marker placement and the anatomical calibration of bony landmarks followed recommendations by the ISB (Wu et al. 2005) and Kontaxis et al (2009). A custom marker cluster was used to dynamically track the scapula (Karduna et al. 2001). The pitching mound was at regulation distance (43’) from the strike zone target. All athletes completed 105 pitches in sets of 15 with a rest of 5 minutes between sets. Ball speed recorded with a radar gun, 3D angular rotations of the glenohumeral joint, scapulo-thoracic joint and thorax with respect to the room were calculated for all throws. The last five pitches of every set were averaged for analysis.Results:Ball speed (Figure 1, n=8 subjects) and peak glenohumeral, scapulo-thoracic and thoracic angular rotations (n=4 subjects) were consistent across all sets. Examples of kinematics at two of these joints are presented across all sets (Figure 2, n=4). Data across all planes demonstrated similar consistency.Conclusion:This study presents a systematic protocol for the study of fatigue during windmill softball pitching. To our knowledge, this is one of the first studies to analyze glenohumeral as well as scapulo-thoracic kinematics during this task. The consistency in the glenohumeral, scapulo-thoracic and torso kinematics during the throwing protocol demonstrates that despite completing 105 pitches, these athletes are able to maintain shoulder kinematics and ball speed during the underhand pitch. This contrasts to the common observation that male overhand pitchers fatigue around 90 pitches.

Bounded Rationality, Retaliation, and the Spread of Urban Violence

Drawing from in-depth interviews with 52 active street criminals, this article examines the grounded theoretic implications of bounded rationality for retaliatory street violence. The bounds on rationality that this article explores are anger, uncertainty, and time pressure. These bounds create imperfections in the retaliatory decision-making process that, in turn, cause asymmetries in the way that reprisal is enacted. Two asymmetries are operative in this regard: strike intensity and target choice. Anger produces asymmetries of both types. Uncertainty and time pressure produce only target-choice asymmetry. All three modalities cause retaliation to be redirected. Redirection promotes the spread of urban violence through conflict spirals.

Soft metrics: What are they and what use are they for the Intelligence Community?

Modern decision making challenges the human capacity to reason in an environment of uncertainty, imprecision, and incompleteness of information. Atop the uncertainty, ranking in the presence of multiple criteria, multiple agents, and heterogeneous sources of information is often the main task to accomplish by the analysts in the Intelligence Community (IC). Soft metrics are attributes of decision criteria that cannot be expressed numerically. These metrics are at the core of a computational engine that is perception-based, with computational 'atoms' expressed in natural language (NL). The soft metrics approach as a basis for natural language-based computing contributes to fast analyses and an efficient use of human resources in contemporary decision making such as: intelligence data analysis, the Global Strike (target pairing), risk analysis, threat assessment, strategic interactions, conflict analysis, and the strategic deterrence assessment.

A perceptual cue on a moving opponent improves the learning of a motor skill from aikido

The effect of different instructional foci on the learning of a motor skill of aikido was investigated. Sixty participants from both sexes with an average age of 14 practiced choku tsuki task, which consisted of hitting a target on the chest of an attacking opponent with a stick. They were divided into four groups: relaxation, with a cue about the relaxed way in which the task should be performed; low hip, with a cue about maintaining hip displacement as low as possible; perceptive, with a cue at the circular target located on the chest of the opponent as they raised their sword to attack; and control, without cues. The dependent variables included measures related to the task goals, movement pattern relative to the task components and kinematic features. Only the perceptive and low hip groups learned the motor skill. The perceptive group obtained better overall performance than the other groups. Learning choku tsuki was improved by the instructional cue “strike target as soon as sword is raised”, establishing the learner’s perceptive attunement to the moving opponent. Learning was also enhanced by the cue "keep hips as low as possible"; however, at a lower level than that of the perceptive cue.

Mechanical shock machine

A mechanical shock machine may consist of a small bench-top device with a built-in pneumatic isolator, the working parts of which are enclosed to prevent injury to the operator. The device to be tested is placed on the test platen of the mechanical shock machine and retained there by mechanical clamps or by a viscous fluid. A bullet-like object is then accelerated toward the underside of the test platen, striking it in free or ballistic flight. The strike target contains a resilient pad. Different thicknesses of this pad produce different durations of the shock pulse, with thicker pads relating to longer duration pulses. A skirt near the outer edge of the test platen is suspended in a viscous shock fluid that absorbs the energy of the bullet strike without a major displacement of the test platen, and reduces second strike effects and ringing of the assembly. The motor inducing acceleration to the bullet is contained and its motion captured within the enclosed volume of the shock machine. The bullet is captured after it has expended most of its energy to the platen assembly by a guard ring and snubber. Return of the motor, bullet and platen to their initial position before initiation of the shock pulse may be by powered reversal or by gravity, or a combination thereof.