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Due to the advantages of direct driven, high thrust density, and high efficiency, flux-switching linear motor (FSLM) is required for many applications, including aerospace and automotive. However, the vibration caused by detent force and difficulties in the assembly produced by the large normal force become the barriers that restrict its development. The paper aims to discuss these issues.

In order to improve the electromagnetic performance of double-sided multi-tooth FSLM (DMTFSLM), a yokeless DMTFSLM with moving primary is proposed and compared with normal DMTFSLM. Moreover, with theoretical analysis, the selection principle of slot-pole number combination is obtained. DMTFSLMs with four slot/pole combinations, 6s/16p, 6s/17p, 6s/19p, 6s/20p, are analyzed based on finite element analysis model. Finally, several parameters of this yokeless DMTFSLM have been optimized to obtain the better performance.

In yokeless DMTFSLM, it is found that the asymmetry of Back-EMF caused by the end-effect is eliminated, which leads to a better thrust force performance in comparison with the normal structure. The small attractive force between the secondary and the primary makes it easier for assembly and also can reduce the friction, which is more suitable for high-speed application. In addition, the best slot-pole combination rule is found through a simple theoretical analysis.

The yokeless DMTFSLM has excellent electromagnetic performance, such as high thrust density, negligible normal force, and small force ripple. It is a strong candidate for high-precision device.

The aim of this paper is to investigate the effect of wing kinematics change on force generation produced by flapping wings.

Forces produced by flapping wings are measured using a load cell and compared for the investigation. The measured forces are validated by estimation using an unsteady blade element theory.

From the measurement and estimation, the authors found that flapping wings produced positive and negative lifts when the wings are attached with the +30° and −30°, respectively.

The authors quantified the characteristics of change in the force generation by flapping wings for three wing kinematics. The wing kinematics was modified by changing the initial wing attachment angle.

The result may be applicable to design of control mechanism for an insect‐mimicking flapping‐wing micro air vehicle, which has only wings without control surfaces at its tail.

The preliminary work may provide an insight for design strategy of flapping‐wing micro air vehicles with compact and handy configurations, because they may perform controlled flight even without control surfaces at their tails.

The work included here is the first attempt to quantify the force generation characteristics for different wing kinematics. The suggested way of wing kinematics change can provide a concept for control mechanism of a flapping‐wing micro air vehicle.

There is an unbalanced magnetic pull between the rotor and stator of the cage induction motor when the rotor is not concentric with the stator. These forces depend on the position and motion of the centre point of the rotor. In this paper, the linearity of the forces in proportion to the rotor eccentricity is studied numerically using time‐stepping finite element analysis. The results show that usually the forces are linear in proportion to the rotor eccentricity. However, the closed rotor slots may break the spatial linearity at some operation conditions of the motor.

This paper aims to present the new information about propeller thrust force contribution to airplane longitudinal stability analysis.

The method presented in this paper is empirical, shows how propeller thrust force derivative can be obtained and gives some additional information about misinterpretation of the propeller thrust effects that are present in the current literature.

New information about propeller thrust force contribution to airplane longitudinal stability analysis has been presented. This information should enable more precise insight in aircraft stability analysis and better understanding of the physical process that occurs during maneuver flight.

The information presented in this paper is new and specific to the propeller aircraft configuration. The methods used here are standard procedure to evaluating propeller thrust force derivative.

The information in this paper presents theoretical results. The method for calculating thrust force contribution to the airplane longitudinal stability is given depending on the propeller type and should enable good engineering results.

To examine a simple testing method of measuring the force to pull a fabric through a series of parallel pins to determine the fabric softness property.

A testing system was setup for fabric pulling force measurements and the testing parameters were experimentally determined. The specific pulling forces were compared with the fabric assurance by simple testing (FAST) parameters and subjective softness ranking. Their correlations were also statistically analyzed.

The fabric pulling force reflects the physical and surface properties of the fabrics measured by the FAST instrument and its ability to rank fabric softness appears to be close to the human hand response on fabric softness. The pulling force method can also distinguish the difference of fabrics knitted with different wool fiber contents.

Only 21 woven and three knitted fabrics were used for this investigation. More fabrics with different structures and finishes may be evaluated before the testing method can be put in practice.

The testing method could be used for objective assessment of fabric softness.

The testing method reported in this paper is a new concept in fabric softness measurement. It can provide objective specifications for fabric softness, thus should be valuable to fabric community.

Granular lubrication is a new lubrication method and can be used in extreme working conditions; however, the obstacle of force transmission characteristics needs to be urgently solved to fully understand the mechanical and bearing mechanisms of granular lubrication.

A flat sliding friction cell is developed to study the force transmission behaviors of granules under shearing. Granular material, sliding velocity, granule size and granule humidity are considered in these experiments. The measured normal and shear force, which is transmitted from the bottom friction pair to the top friction pair via the granular lubrication medium, reveals the influence of these controlling parameters on the force transmission characteristics of granules.

Experimental results show that a low sliding velocity, a large granule size and a low granular humidity increase the measured normal force and shear force. Besides, a comparison experiment with other typical lubrication styles is also carried out. The force transmission under granular lubrication is mainly dependent on the force transmission path, which is closely related to the deconstruction and reconstruction of the force chains in the granule assembly.

These findings reveal the force transmission mechanism of granular lubrication and can also offer the helpful reference for the design of the new granular lubrication bearing.

This paper aims to propose a type of T-shaped two-axis force sensor for measuring the forces in x- and z-axes. The developed sensor has a simple structure and can be effectively assembled into compact devices.

A T-shaped plate, with both ends fixed on a base, is used as the substrate of the sensor. Eight strain gauges are placed in the root of the plate or near the sensor head, which can construct two full Wheatstone bridges on the upper and lower surfaces of the plate. When the x- or z-axes forces are applied to the sensor head, different deformation can be generated to the strain gauges. Therefore, the two Wheatstone bridges can be constructed with a different configuration for measuring the forces in x- or z-axes, respectively.

A prototype was designed and constructed and experiments were carried out to test the basic performance of the sensor. It has been verified that the developed sensor could measure the x- and z-axes forces independently with a high resolution of 2.5 and 5 mN, respectively.

Only one thin plate was used in the design, the forces in x- and z-axes could be measured independently and simultaneously, which made the sensor with a simple structure and compact size. Experiments were also verified that there was no crosstalk error occurred in one axis when the force was applied to the other axis.

This paper aims to critically examine the lie detector test policy of the Nigeria Police Force to determine if the policy is capable of curbing corruption in the Nigerian Police Force.

The analysis took the form of a desk study, which analyzed various documents and reports such as the report by the United Nations Office on Drugs and Crime and the National Bureau of Statistics titled “Corruption in Nigeria – Bribery: Public Experience and Response,” Transparency International’s Corruption Perceptions Index 2017, the report by the International Police Science Association and the Institute for Economics and Peace.

This paper determined that the lie detector test policy of the Nigeria Police Force could achieve its desired objectives if the following recommendations are implemented: The Nigeria Police Reform Trust Fund bill should be given accelerated consideration in the Senate and House of Representatives based on its urgency and significance for the new lie detector test policy of the Nigeria Police Force. There is need for the Nigerian Police to have enough funds to conduct trainings for police personnel who are chosen as examiners for the lie detector tests. The Nigerian National Assembly will need to pass an Act to provide for the licensing of detection of deception examiners – commonly known as polygraph or lie detector operators – and regulation of that profession. The act should set forth the conditions under which persons may be admitted to practice detection of deception with a polygraph, the standards they must observe and the types of polygraph devices that they may henceforth be used lawfully. This is what was done in the State of Illinois. The Nigeria Police Force is advised to make use of two examiners for the lie detector test: one in-house examiner and one external examiner. The external examiner may be from another country in which corruption is not at a high rate, and must be someone of high integrity and professional competence. This measure may reduce the risk of bribery and corruption in the system. It will also bring more integrity and transparency into the system. The external examiner may also carry out “on the job training” with the in-house examiner while the polygraph exercise is going on. The Nigeria Police Force must make a new policy that mandates that all transactions relating to the purchase of polygraph machines must be conducted in an open and fair manner that recognizes the need for the transaction to be done directly with the seller, and not through a sales agent. This policy may help prevent a situation where a corrupt sales agent connives with a corrupt police officer to defraud the police unit. An ongoing approach to screening should be considered for specific positions, as circumstances change, or for a comprehensive review of departmental staff over a period. The Nigeria Police Force should have a policy that mandates that the lie detector test should be taken once in five years by all staff of the Nigeria Police Force. For staff in very sensitive positions, the lie detector test should be taken every three years. This will enable the lie detector policy to be more effective. Let us take, for example, a person passes the lie detector test genuinely without any influence of corruption; there is still a possibility that the person may change over time. The temptation to follow current employees to collect bribes is very high. But if the Nigeria Police Force put a policy in place that mandates every police personnel to take the lie detector test every five years starting from the first five years after recruitment, the cankerworm called corruption may be curbed effectively. Imagine if every police personnel knew that they were going to be asked by an examiner, five years after working, to confirm if they ever collected bribe during the time they served in the police force; most employees will desist from taking bribes or engaging in corrupt acts. The above measure will ensure that current employees who are chosen as examiners for the lie detector tests are fit and proper persons for the job.

This paper focuses on the new lie detector test policy of the Nigeria Police Force. It does not address the other anti-corruption policies of the Nigeria Police Force.

This paper offers a critical analysis of the lie detector test policy of the Nigeria Police Force. It will provide recommendations on how the policy could be strengthened. This is the only paper to adopt this kind of approach.

The purpose of this paper is to present an analysis of the force ripples of an open slot permanent magnet linear synchronous motor (PMLSM). A calculation procedure using 2D finite elements method (2D‐FEM) is then evaluated with experimentations.

First, the studied PMLSM and its main features are introduced. Then, the 2D‐FEM model used to study the motor is presented. The methods used to calculate the force and the meshing procedures are also highlighted. The calculated no‐load force is compared to measurements. Lastly, the validated model is used to study the influence of the current magnitude on the force ripples at load.

In addition to the no‐load case, the influence of the current magnitude on these forces is presented.

The paper is orientated with a sound industrial background. For that reason, the impact of the current saturation on the thrust generation is presented via the evolution of the thrust coefficient, which is the force to the RMS currents ratio.

The perfect interlacing of needle and bobbin thread in the stitch formation process and seam appearance depends first of all on correct pre‐tension of the tension regulator. Changes in the pre‐tension settings also have a direct influence on the tensile force during the sewing process. This contribution presents the influence of pre‐tension in a defined area on the tensile force in important phases of the stitch formation process. In addition the influence of the stitch velocity on tensile force was investigated. On the basis of statistic analysis it was ascertained in which pre‐tension area and stitch velocity the significant differences between tensile forces occurred.