• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.2
• /
• pp.165-170
• /
• 2011

In this paper, wind force coefficient by wind tunnel experiment is obtained to compute the accurate wind force of the gantry crane model to be used for mobile harbor ship. The first crane model was tested under 20, 30, 40, 52m/s, partially 58m/s and the wind force coefficient is about 2.0 which is very close to the suggested theoretical value. The other is the more reliable crane model and tested under 20, 30, 40m/s also giving the similar realistic wind force coefficient. Also structural analysis of crane model was performed giving the reliable stress level. Since the rolling effect is important for mobile harbor ship, the safety of the crane on the ship needs to be guaranteed. For this, using the computed reaction forces, a tie-down design is suggested which connects the crane and ship to resist the turnover motion of the crane.

• Progress in Medical Physics
• /
• v.28 no.4
• /
• pp.164-170
• /
• 2017

One of the methods to consider the effect of respiratory motion of a tumor target in radiotherapy is to establish a treatment plan with the internal target volume (ITV) created based on an accurate analysis of the target motion displacement. When this method is applied to intensity modulated radiotherapy (IMRT), it is expected to yield a different treatment dose distribution under the motion condition according to the IMRT method. In this study, we prepared ITV-based IMRT plans with conventional IMRT using fixed gantry angle beams, RapidArc using volumetric modulated arc therapy, and tomotherapy using helical therapy. Then, the variation in dose distribution caused by the target motion was analyzed by the dose measurement in the actual motion condition. A delivery quality assurance plan was prepared for the established IMRT plan and the dose distribution in the actual motion condition was measured and analyzed using a two-dimensional diode detector placed on a moving phantom capable of simulating breathing movements. The dose measurement was performed considering only a uniform target shape and motion in the superior-inferior (SI) direction. In this condition, it was confirmed that the error of the dose distribution due to the target motion is minimum in tomotherapy. This is thought to be due to the characteristic of tomotherapy that treats the target sequentially by dividing it into several slices. When the target shape is uniform and the main target motion direction is SI, it is considered that tomotherapy for the ITV-based IMRT method has a characteristic which can reduce the dose difference compared with the plan dose under the target motion condition.

• KIPS Transactions on Software and Data Engineering
• /
• v.6 no.5
• /
• pp.223-228
• /
• 2017

SMT is an device that picks up electronic components and does precise placing onto PCBs. In order to do this, it stops in front of a camera installed in the middle to go over vision inspection. And after that it is move for placing. There are 16 different types of routes in this process. This paper compared to the moving time of three methods in the (sLa-Camera-pLa)type. The first method is stopping in front of the camera for vision inspection and placing components onto PCBs(stop-motion). The second method is moving in front of the camera for vision inspection without stopping(fly1-motion). The third method is inspecting the components when the speed of the X axis, the Y axis is the best and is placing components onto PCBs(fly2-motion). This paper shows the moving time of three methods is same. Therefore we proved that the stop-motion method can be placing in the fastest time without changing structure of the device in the (sLa-Camera-pLa)type.

• Journal of radiological science and technology
• /
• v.42 no.3
• /
• pp.217-222
• /
• 2019

The purpose of this study is to evaluate the dose distribution by gantry rotation and MLC moving speed on treatment planning system(TPS) and linear accelerator. The dose analyzer phantom(Delta 4) was scanned by CT simulator for treatment planning. The planning target volumes(PTVs) of prostate and pancreas was prescribed 6,500 cGy, 5,000 cGy on VMAT(Volumetric Modulated Arc Therapy) by TPS while MLC speed changed. The analyzer phantom was irradiated linear accelerator using by planned parameters. Dose distribution of PTVs were evaluated by the homogeneity index, conformity index, dose volume histogram of organ at risk(rectum, bladder, spinal cord, kidney). And irradiated dose analysis were evaluated dose distribution and conformity by gamma index. The PTV dose of pancreas was 4,993 cGy during 0.1 cm/deg leaf and gantry that was the most closest prescribed dose(5,000 cGy). The dose of spinal cord, left kidney, and right kidney were accessed the lowest during 0.1 cm/deg, 1.5 cm/deg, 0.3 cm/deg. The PTV dose of prostate was 6,466 cGy during 0.1 cm/deg leaf and gantry that was the most closest prescribed dose(6,500 cGy). The dose of bladder and rectum were accessed the lowest during 0.3 cm/deg, 2.0 cm/deg. For gamma index, pancreas and prostate were analyzed the lowest error 100% at 0.8, 1.0 cm/deg and 99.6% at 0.3, 0.5 cm/deg. We should used the optimal leaf speed according to the gantry rotation if the treatment cases are performed VMAT.

• The Academic Congress of Korean Shoulder and Elbow Society
• /
• 2009.03a
• /
• pp.175-175
• /
• 2009

Despite its importance for the understanding of joint kinematics in vivo, there has been few studies about shoulder joints. The purpose of this study is to analyze the glenohumeral joint during internal and external rotation at 90 degrees of abduction using in vivo noninvasive motion analysis system. MRI was performed for the following seven positions from maximum internal rotation to maximum external rotation at intervals of 30 degrees. We used 3D-gradient echo sequencing (TR: 12 ms, TE: 5.8 ms, 0.8 mm-slice thickness). Our method is based on matching three-dimensional MR images by the similarity of the image intensity. We analyzed the in vivo three-dimensional motions of the glenohumeral and scapulothoracic joint during this motion. In scapla plane, the mean rotation angle of the glenohumeral join was 105.5 degrees ($SD{\pm}39.0^{\circ}$). The mean rotation angle of the scapulothracic joint was 27.5 degrees ($SD\;{\pm}\;7.7^{\circ}$). The contribution ratio is almost 3.8:1 of glenohumeral and scapulothracic joint respectively.

• Journal of Digital Convergence
• /
• v.13 no.1
• /
• pp.269-274
• /
• 2015

According to the development of IT industry, prevalence of AOI equipment is spreading, and also requiring the high resolution of the camera used in the equipment. The weight of the camera is increased to obtain a high resolution, and thus increases the vibration displacement is a problem occurring in the picturing, camera motion control also becomes difficult. In this study, using a finite element analysis program NX/NASTRAN, the transient response of the camera was analysed which is subjected to an impact force due to inertia. The finite element analysis result is correlated with laser interferometer measurement. When AOI equipment is restructuring, the correlated finite element analysis model can be used to verify the authenticity of the new design.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1365-1370
• /
• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and its maintenance is easy. However, it gives almost the same performance. Various observers for estimating the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of the rail-mounted quayside crane is constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the pilot crane constructed. Experimental results are provided.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1897-1900
• /
• 2004

In recent years, a lot of industrial equipments have serial communication channel such as FieldBus (CAN, Profibus, etc.) or Ethernet that provides real time communication between industrial equipments. Theses applications include gantry crane, robot, chip mounter, etc.. In this paper, we discuss the synchronization technique for networked multi-motor systems where controllers (commercial servo amps) are distributed and interconnected by CAN (Controller Area Networks). We first describe the equivalent model for the individual servo-amp and motor using the frequency response. We design the $H{\infty}$ controller for motion synchronization. Finally, the synchronization technique using the equivalent model and the $H{\infty}$ controller is verified by the simulation and the experiment.

• Journal of Welding and Joining
• /
• v.27 no.2
• /
• pp.57-62
• /
• 2009

This research was carried out to improve the productivity in the subassembly process of shipbuilding through optimal work planning for the shortest work time. The work time consist of welding time, moving time of gantry, teaching time of robot and robot motion time. The shortest work time is accomplished by even distribution of work and the shortest welding sequence. Even distribution of work was done by appling the simple algorithm. The shortest work sequence was determined by using GA. The optimal work planning decreased the total work time of the subassembly process by 4.1%. The result showed the effectiveness of the suggested simple algorithm for even distribution of work and GA for the shortest welding sequence.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.142-142
• /
• 2000

During the operation of crane system in container yard, it is necessary to control the crane trolley position so that the swing of the hanging container is minimized. Recently an automatic control system with high speed and rapid transportation is required. Therefore, we designed a controller to control the crane system with disturbances. In this paper, Ive present the neural network two degree of freedom PID controller to control the swing motion and trolley position. Then we executed the computer simulation to verify the performance of the proposed controller and compared the performance of the neural network PID controller with our proposed controller in terms of the rope swing and the precision of position control . Computer simulation results show that the proposed controller has better performances than neural network PID with disturbances.