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We conducted a study to analyze the impact of short aramid fibers (AFs) on the melt-rheological behavior, thermal transition, thermal stability, and mechanical durability of thermotropic liquid crystal polyesters (TLCPs). By using different AF loading contents ranging from 3–15 wt%, we produced TLCP matrix composites through masterbatch-based melt-compounding and injection-molding. The SEM images and FT-IR spectra demonstrate that the AFs are dispersed in the TLCP matrix with a microfibrillar structure through good interfacial adhesion caused by specific intermolecular interactions between the TLCP and AFs. As a result, the complex viscosity, shear storage/loss moduli, and thermal transition (melt-crystallization, glass transition, and melting) temperatures of the composites increase with increasing AF filler content. However, the melt-crystallization and melting enthalpies increase only at low AF loading contents of 3–5 wt%. At high AF contents of 7–15wt%, the enthalpies decrease owing to the partial aggregation of AF fillers. The thermogravimetric analysis proves that the thermal stability of TLCP/AF composites improves when the AF filler is introduced. The dynamic mechanical analysis using the stepped isothermal method shows that the addition of 5 wt% AF to the TLCP leads to an approximately 150% improvement in elastic moduli and long-term mechanical durability at elevated temperatures.

The KOMAC facility consists of low-energy components, including a 50-keV ion source, a lowenergy beam transport (LEBT), a 3-MeV radio-frequency quadrupole (RFQ), and a 20-MeV drift tube linac (DTL), as well as high-energy components, including seven DTL tanks for the 100-MeV proton beam. The KOMAC includes ten beam lines, five for 20-MeV beams and five for 100-MeV beams. The peak beam current and the maximum beam duty are 20 mA and 24% for the 20-MeV linac and 20 mA and 8% for the 100-MeV linac, respectively. Four high-voltage convertor modulators are used. Each modulator drives two or three klystrons. The peak output power is 5.8 MW, and the average power is 520 kW with a duty of 9%. The pulse width and repetition rate are 1.5 ms and 60 Hz, respectively.

The beam diagnostics instrument used to measure the beam properties is one of the important devices for the 100-MeV proton linear accelerator of the KOrea Multi-purpose Accelerator Complex (KOMAC). A data acquisition system (DAQ) is required to collect the output beam signals conditioned in the analog front-end circuitry of a beam loss monitor (BLM) and a beam position monitor (BPM). The electrical beam signal must be digitized, and the sampling has to be synchronized to a global timing system that produces a pulse signal for the pulsed beam operation. The digitized data must be accessible by the experimental physics and industrial control system (EPICS)-based control system, which manages all accelerator control. An input output controller (IOC), which runs Linux on a central process unit (CPU) module with a peripheral component interconnect (PCI) express-based Analog-to-digital converter (ADC) card, has been adopted to satisfy the requirements. An associated Linux driver and EPICS device support module have also been developed. The IOC meets the requirements, and the development and maintenance of software for the IOC is very efficient. In this paper, the details of the DAQ system for the BLM and the BPM with the introduction of the KOMAC beam-diagnostics devices, along with the performance, are described.

The 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC) has been developed. The beam service started this year after performing the beam commissioning. If the very sensitive and essential equipment is to be protected during machine operation, a machine interlock system is required, and the interlock system has been implemented. The purpose of the interlock system is to shut off the beam when the radio-frequency (RF) and ion source are unstable or a beam loss occurs. The interlock signal of the KOMAC linac includes a variety of sources, such as the beam loss, RF and high-voltage converter modulator faults, and fast closing valves of the vacuum window at the beam lines and so on. This system consists of a hardware-based interlock system using analog circuits and a software-based interlock system using an industrial programmable logic controller (PLC). The hardware-based interlock system has been fabricated, and the requirement has been satisfied with the results being within 10 µs. The software logic interlock system using the PLC has been connected to the framework of with the experimental physics and industrial control system (EPICS) to integrate a variety of interlock signals and to control the machine components when an interlock occurs. This paper will describe the design and the construction of the machine interlock system for the KOMAC 100-MeV linac.

The Proton Engineering Frontier Project developed a 13-MHz pulsed, RF cavity for heavy-ion implanter applications. Typically, slow changes in the room temperature and the mechanical vibrations of the vacuum device may be primary sources of disturbances, and the accelerating cavity of the implanter may not be able to operate at the resonance frequency owing to disturbance effects. We need a voltage-controlled oscillator phased-locked loop circuit to make a control system that could suppress the disturbance effects; thus, the accelerating gradient of the cavity always reached a peak level for a given input power and coupling. An analog-circuit-based RF-frequency-tracking system was developed. Next, we obtained the optimal control parameters for the key control components. Finally, we measured the system performance between an open loop and a closed loop. The key point of the system design is to control the driving frequency that is used to operate the RF source by keeping the phase at around 0 degrees with respect to the resonance peak of the cavity. The experimental results showed that the fluctuations of the control loop error signal were suppressed by about a factor of 10. The presented feedback loop is implemented as a standard proportional controller. The loop p-gain is 120 k.

The Proton Engineering Frontier Project (PEFP) has developed an integrated control system for beam commissioning of its 100-MeV proton linear accelerator. The final goal of the PEFP control system for beam commissioning is to develop a network of attached and distributed control systems. The PEFP control system was designed into the basic control structure of three groups including the central control system, the local control system, and the console system. The central control system is responsible for the timing synchronization and interlock. The local control system is responsible for the distributed control system for several linac components, such as the vacuum, power supply, data acquisition, RF, and so on. The console system is responsible for the user interface as a control system client. In order to implement the control system, we have adopted an Experimental Physics and Industrial Control System (EPICS) software framework as the standard development tool. The EPICS is based on a distributed architecture that provides several solutions, such as independent programming tools on several hardware and operating-system platforms. The Input Output Controllers (IOCs) of the PEFP control system have been tested with a wide variety of hardware solutions from a personal computer to embedded devices. In this paper, we will present the details of the integrated control system for beam commissioning of the PEFP 100-MeV proton linac.

The Proton Engineering Frontier Project (PEFP) 20-MeV proton linear accelerator is currently operating at the Korea Atomic Energy Research Institute (KAERI). The ion source of the 100-MeV proton linac needs at least a 100-hour operation time. To meet the goal, we have developed a microwave ion source that uses no filament. For the ion source, a remote control system has been developed by using experimental physics and the industrial control system (EPICS) software framework. The control system consists of a versa module europa (VME) and EPICS-based embedded applications running on a VxWorks real-time operating system. The main purpose of the control system is to control and monitor the operational variables of the components remotely and to protect operators from radiation exposure and the components from critical problems during beam extraction. We successfully performed the operation test of the control system to confirm the degree of safety during the hardware performance.

A 20-MeV proton accelerator has been developed and tested at the Korea Atomic Energy Institute (KAERI) by the Proton Engineering Frontier Project (PEFP). Beam phase was measured at the end of the 20-MeV accelerator by using the beam position monitor (BPM) signal. The beam current and phase were measured by changing the relative RF phase between the 3-MeV radio frequency quadrupole (RFQ) and the 20-MeV drift; tube linac (DTL), and the results were compared with those simulated by using the PARMILA code. In tins paper, the beam phase measurement results are presented, and the phase scan results based on the normal operating condition are compared with the simulation results.

Development of the Resonant-Frequency Monitoring System for the PEFP DTL Young-Gi Song, Han-Sung Kim, Hyeok-Jung Kwon and Yong-Sub Cho Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Received 4 September 2008) A 20-MeV, 20-mA proton linac, which is comprised of a 50-keV proton injector, a 3-MeV radio frequency quadrupole (RFQ) and 20-MeV drift tube linac (DTL), has been developed in the Proton Engineering Frontier Project (PEFP). For a stable and e cient acceleration of a proton beam, the resonant frequency of the DTL cavities should be matched to the high power RF driving frequency. In PEFP DTL, a resonant control cooling system (RCCS) will be used to control the resonant frequency. The main objective of this study is to measure and transfer the resonance frequency error to the RCCS by measuring the RF eld pro le in the cavity. The algorithm derived by using a state-space model is used to represent the resonant frequency error. The control application program was developed with a VME-based PCI mezzanine card (PMC) extended board and a multitasking method based on the VxWorks. We tested the algorithm, the control board and the application program by using a dummy cavity. In this paper, the algorithm, the system con guration and the test results are presented. PACS numbers: 29.17.+w

We have developed an EPICS-based control system for a multicusp negative ion source based on a VME IOC software, a sequencer controlling a closed proportional integral (PI) loop, and an interlock. The PI loop was tuned by a step input voltage, and tuning gains of the proportion and integral have been determined. The PI logics, developed by using standard proportional-integral-derivative records, can control the arc current within +/-1% of a given set value.

Palm-print recognition is recently emerged as new personal verification for reliable identification and alternative for latent comparison of unsolved cases for suspect criminals in forensic science. This paper deals with comparison of live palm-print using sub image divided from the whole image by capturing of high resolution live scanner. Proposed method is very robust and accurate with live sample test set with comparison of fingerprint template matching.

Palm-print recognition is recently emerged as new personal verification for reliable identification and alternative for latent comparison of unsolved cases for suspect criminals in forensic science. This paper deals with comparison of live palm-print using sub image divided from the whole image by capturing of high resolution live scanner. Proposed method is very robust and accurate with live sample test set with comparison of fingerprint template matching.

Off-line handwritten numeral recognition is a very difficult task. It is hard to achieve high recognition results using a single set of features and a single classifier, since handwritten numerals contain many pattern variations which mostly depend upon individual writing styles. In this paper, we propose a recognition system using hybrid features and a combined classifier. To improve recognition rate, we select mutually beneficial features such as directional features, crossing point features and mesh features, and create three new hybrid feature sets from them. These feature sets hold the local and global characteristics of input numeral images. We also implement a combined classifier from three neural network classifiers to achieve a high recognition rate, using fuzzy integral for multiple network fusion. In order to verify the performance of the proposed recognition system, experiments with the unconstrained handwritten numeral database of Concordia University, Canada were performed, producing a recognition rate of 97.85%.

A fast timing system has been developed to control transistor transistor logic (TTL) trigger signals which are used to extract the pulsed proton beam from an ion source with the precision of less than submicro seconds. The system has been designed to set a delay and duty of the pulses, respectively, and prohibit the beam pulse by an external interlock signal. The system is based on VME which is composed of VME CPU and fast I/O boards with fan-out modules. The software of the system has been developed by the record/device supports and channel access in the core of the EPICS environments. In the paper, we describe software configurations and hardware drivers.