Earticle

A needleless automatic injection syringe (Jet Injector) is a device that delivers drugs into the skin and tissues using high-speed fluid jets without the use of injection needles. Jet Injector's core technology is to penetrate the stratum corneum of the skin by converting pressure energy generated in the driving unit into fluid kinetic energy, and structural loads and dynamic responses generated in this process directly affect the performance and durability of the device. Therefore, the structural mechanical design of the drive unit can be said to be a key factor in securing the reliability and injection accuracy of the Jet Injector. This paper is intended to provide the basis data for the basic design of the drive unit of the "Animal Vaccine-free Automatic Injection Syringe (hereinafter referred to as the "Jet Injector"), and this calculation data provides basic data for the design. Based on this, it is possible to design the drive unit according to various assumptions and given conditions, and the expected performance can be reasonably inferred according to the design.

A needle-free automatic injection syringe is a device that delivers drugs into the skin and tissues using a high-speed fluid jet without using an injection needle. This technology is attracting attention as an efficient means of vaccine delivery in the veterinary and livestock fields that reduce the risk of cross-infection and require mass vaccination. In particular, animal vaccination provides various advantages over conventional needle injection methods in terms of worker safety, inoculation speed, and maintenance cost. This paper was conducted to solve the problem of pressure loss at the nozzle discharge side of the existing Jet Injector in designing the flow path of the animal vaccine-free automatic injection syringe nozzle. To this end, the flow rate of the air tank (receiver) was determined, the needleless injection was basically designed, and the simulation was performed to prove its validity. Through these series of processes, the design review of the driving part was completed, and through this, the nozzle and neck-up shape were proposed to obtain the desired performance. However, it is thought that more trial and error are needed to commercialize such a needleless injection to humans.

A needle-free automatic injection syringe is a device that delivers drugs into the skin and tissues using a high-speed fluid jet without using an injection needle. This technology is attracting attention as an efficient means of vaccine delivery in the veterinary and livestock fields that reduce the risk of cross-infection and require mass vaccination. In particular, animal vaccination provides various advantages over conventional needle injection methods in terms of worker safety, inoculation speed, and maintenance cost. Among these drivers, Jet Injector Nozzle's flow path design is very important in needleless automatic injection syringes. This paper was conducted to solve the problem of pressure loss at the nozzle discharge side of the existing Jet Injector in designing the flow path of the animal vaccine-free automatic injection syringe nozzle. To this end, CAE was performed and the optimum design of the flow path required by the company was performed, and a large flow rate was possible in the optimal shape design, but this focuses on the nozzle flow path, which requires a review of design additions of cylinders and motors on the rear side.

Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples.

We propose a new concept of transmission-tribology design based on the investigation of development and existing problems of the gear drive and tribology. The content of transmission-tribology and transmission-tribology design is probed. Some effective methods of transmission-tribology design is probed. Some effective methods of transmission-tribology design are put forward. Partial achievements in this research are introduced tersely. Mechanical transmission, which is represented by the gear drive, and tribology are two main branches of mechanical engineering. They have their own definite research field. In recent years, we have been doing our utmost to suggest combining mechanical transmission-tribology and transmission-tribology design. Partial achievements in this research area are obtained.

Model trains should have very similar motion characteristics to real trains in order to provide realistic feeling to their operators. Main purpose of dynamic analysis of model trains is to predict velocities in straight and circular tracks and estimate stopping distance after power shut off. Equations of motion for a model train are derived that relates velocity, traction, rolling resistance, and pulling force. Also, energy equations for calculating stopping distance after power shut off are derived. Experiments with model trains are preformed to measure velocity, rolling resistance, slip, and stopping distance. The results are compared with the prediction based on the equations of motion, and they showed good agreement. It can be concluded that the prediction is more accurate when the slip between wheel and rail is accounted for. The analysis procedures can be applied to determining various design factors in model trains.

In this study, we analyzed wind torque from aerostatic force coefficients of radar structures according to the Reynolds number. The test was conducted in the KOCED Wind Tunnel Center at Chonbuk University, and the wind tunnel test model was at 1:8 scale. Wind speeds were in the range of 5-26 m/s to determine Reynolds number independence. Test results of the present radar system were not impacted by the Reynolds number. Maximum drag coefficient was 1.43 under an angle of attack of 0 degrees and angle of the vehicle was 135 degrees, while maximum positive pressure coefficient was 1.21 at the side of plane in angle of attack of 0 degrees. Maximum negative pressure coefficient was -2.06 at the corner front of the plane at an angle of attack of 90 degrees. To verify wind torque in the wind tunnel test, a drive system was designed and manufactured. A wind speed of 26 m/s, the maximum average operating wind speed condition, was applied to validate the radar was driven normally. Results of this study may be used as an evaluation method for wind speed tests of radar systems and large structures that cannot be used for wind tunnel tests.

This paper deals with the design and modal characteristics analysis of a drive-train for a paralleltype hybrid electric vehicle (HEV). The function of the drive-train system (DTS) in the HEV combines or divides the torque and velocity from the internal combustion engine along with the induction motor. The system consists of a compound planetary gear and unit's electromagnetic clutch to provide the operation modes such as Engine Only (EO), Electric Vehicle (EV), and Hybrid Electric Vehicle (HEV) modes. In order to investigate the characteristics of the velocity and torque flow for the system, dynamic models of the HEV with DTS are derived from the prototype DTS. The performance of the derived dynamic models is evaluated by both computer simulations and experiments according to each mode.

At the early stages of engineering design, a number of design concepts may be suggested. With a great degree of freedom, making a good choice may be a challenge at this stage. In this study, a simplified evaluation criterion for design concepts is presented based on cost, simplicity and safety. Cost is estimated by the amount of materials and the required level of tolerance. Simplicity is represented by the number of parts, assembly steps, and fasteners. Safety is assessed by the level of potential failure. The proposed criterion is applied to an example design of driving mechanisms for cervical vertebrae massage machine.

Laser assisted machining (LAM) is machining method that performs a machining for workpieces using laser beam preheating. LAM is in the early stage of its applications and has only been used in limited fields including turning, planning and micro end-milling throughout the world. LAM system should be able to move to the laser radiation direction and to rotate on a tool path for machining of complex shapes. A laser module with two-axis manipulator is designed in this study. It has been performed static structural analysis and shape modification of the manipulator. As the results of shape modification it has been obtained better results than the initial model. These results will be able to use in development of the two-axis manipulator.

In this paper, using interleaved power factor correction how to improve the inverter efficiency studied. Interleaved method can reduce the conduction losses and the inductor energy. Generally, critical conduction mode (CRM) boost PFC converter used low power level because of the high peak currents. if you use the interleaved mode, CRM PFC can be used medium or high power application. interleaved CRM PFC can reduce current ripple for higher system reliability and size of buck capacitor and EMI filter size. Interleaved CRM PFC that is installed in front of inverter can maintain the constant voltage regardless of the input voltage.

Many algorithms to enhance a speed performance of a robot have been studied, but it's rare to consider disign aspect of a robot arm for time optimal problem. In this paper, section demensions of a robot arm and a velocity profile of an end-effector were optimally designed to minimize the cycle time. Capacity of actuators, deflections of end-effector, and a fundamental natural frequency of the robot arm were constrained in optimal design. For a given path with a trapezoidal velocity profile, torques of each joint were calculated using the inverse kinematics and dynamics. For the SCARA type robot which is mainly used for assembly tasks, the time optimal design of each robot arm id presented with the above constraints.

Planetary gear systems have several advantages over traditional gearboxes with parallel axis gear shafts. The planetary gearbox arrangement also creates greater stability due to the even distribution of mass and increased rotational stiffness. However, gears in planetary gear systems occasionally have a short-life due to wear and breakage by repetitive load during operation time. In this study, we evaluated variables of the strength design for each part and conducted structural analysis of seven cases of the planetary gear system. The result of structural analysis was applied to shape optimization method and obtaining the weight lightening designed value. Subsequently, the planetary gear system was performed to ensure the durability of gears during operation time with miner's rule.

A Direct Drive Valve(DDV) hydraulic actuation system which is commonly used as an aircraft's control surface driving actuator has multi-loop control structure to ensure its safety operation. However, because of not perfect matching of one self channel characteristics with the others, the servo valve driving current of each channel can be widely different. Therefore, the long-time use of DDV actuator without any correction of these channel current offsets will cause the problem of performance or life expectancy degradation due to unwanted heats in the linear motor. A current equalization loop structure which can minimizes current offsets between channels is introduced and designed. The performance of the current equalization loop is investigated and verified through the analytic and experimental ways.

In this paper, mechanism design of optical pickup actuator for fast access is proposed. This actuator is composed of moving magnet type actuator and moving coil type actuator for tracking and fine motion, respectively. Moving magnet type tracking actuator is configurated by two permanent magnets and four air-core solenoids. Additional damper by induced current in tracking actuator can reduce the transient vibration between the coarse seeking servo and fine seeking servo. Variable stiffness can be acquired by applying current to air-core solenoid simply. This actuator can achieve fast access by these additional damper and stiffness. Performance of this actuator is predicted through the FEM, simulation and simple experiment. Settling time for transient vibration is reduced to 14.7% according to simulation result.

본 논문은 경사면과 단차 등의 비평탄 지형 극복과 장애물 회피가 가능하도록 지능적인 센서 신호처리와 다양한 구동방식을 보유한 바퀴 구동형 소형 지능 로봇의 설계와 구현을 목적으로 한다. 비평탄 지형 극복을 위해 편심 기어 구조를 제안하였으며, 실시간 균형 유지를 위해 최적의 센서 신호처리를 적용하였고, 장애물 극복을 위해 LiDAR 센서를 활용한 장애물 인식 및 좁은 공간에서의 탈출이 가능한 전방위 구동 방식을 제안하고 설계하였다. 로봇의 지능적 요소를 구현하고 제어하기 위해 최적의 임베디드 시스템을 설계하고 구축하였다.

The purpose of this paper is to design and implement a wheel-driven small intelligent robot with intelligent sensor signal processing and various driving methods to overcome non-flat terrain such as slopes and steps and avoid obstacles. An eccentric gear structure was proposed to overcome non-flat terrain, optimal sensor signal processing was applied to maintain real-time balance, and an omnidirectional driving method that enables obstacle recognition and escape from a narrow space using a LiDAR sensor was proposed and designed to overcome obstacles. An optimal embedded system was designed and constructed to implement and control the intelligent elements of the robot.

This paper deals with the position control fur a feed drive system in CNC milling machine, which utilizes a modified error signal for the elimination of steady-state error. A linear time-invariant (LTI) system has consistent properties in response to standard test signal inputs. Those also appear in an error curve acquired from the response. From such properties, constructed is an error model for the position control of the feed drive. And then added is the output of the error model to the current error signal. Consequently the resulting proportional control system brings performance improvement in view of the steady-state error. The effectiveness of the proposed scheme is confirmed through simulations and experiments.

The unbalanced heavy-loaded elevation-driving system is composed of link-mechanism, hydraulic cylinder and compensator for the static unbalanced moment of the load. Control and compensation of elevation-driving system is very difficult because these mechanisms imply highly nonlinear properties due to hydraulic fluid characteristics and mechanical rotation of link-mechanism. In this study, through the analysis of the link-mechanism, the optimal design of the link-mechanism is suggested. Also to estimate the control performance of the unbalanced, heavy-loaded servo-controlled system, modeling and simulation of nonlinear system are carried out. To prove the validity of performance estimation program, simulation results are compared with the experimental results. Both results are similar, therefore this program will be helpful to study the improvement of the system control performance.

In four-wheel-drive vehicle, improving traction with the road surface enhances the vehicle's ability to respond to various driving conditions, increasing its overall versatility. Consequently, various studies have been conducted on four-wheel-drive vehicles that support torque distribution through electronic control. The driving unit that operates the transfer case assists in smooth torque distribution by providing high torque. Therefore, this study developed a reduction mechanism by vertically arranging a planetary gear set in the driving unit to increase the reduction ratio. To achieve this, a common ring gear with 52 teeth was used, and the design included a first-stage planetary gear with a sun gear having 18 teeth, a planet gear with 17 teeth, a second-stage sun gear with 12 teeth, and a planet gear with 20 teeth. The corresponding tooth profiles and structures were also designed. Based on this, a transfer case drive reduction module was developed, which improved torque performance: the first-stage planetary gear system provides 4.23 kgf·m of torque, and the second-stage planetary gear system achieves a final torque of 5.98 kgf·m