• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2003.10a
• /
• pp.39-42
• /
• 2003

We studied the vertical launch performance of the Laser-driven In-Tube Accelerator (LITA). This device is primarily characterized by accelerating a projectile in a tube. Owing to the confinement effect, the thrust performance is enhanced. The driver gas can be specified and its pressure be turned so that the impulse performance is optimized. In the experiments, a 3.0-gram projectile was vertically launched. The effects of the projectile exit condition, the laser beam incident direction and the driver gas species were experimentally studied.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10a
• /
• pp.581-583
• /
• 2000

We are studied on the performance optimized synthesis and mapping of design on to one or more FPGA device. our multi-phased approach optimized the key parameters that affect performance by adequately modeling the impact on wire length, routability, and performance during technology mapping to produce designs that have high performance and high routability potential.

• Journal of Biomedical Engineering Research
• /
• v.44 no.1
• /
• pp.73-79
• /
• 2023

The purpose of this study is to derive medical devices with different management systems through comparison of domestic and overseas medical device product classification systems and to propose management conversion measures for the products. The definitions of medical devices were compared and the scope of medical devices defined by each country was confirmed through surveys of the Medical Device Act, Federal Food, Drug & Cosmetics Act (FD&C) in the U.S., and Medical Device Regulations (MDR) in Europe. Using the Ministry of Food and Drug Safety's regulations on medical device products and grades, 21 CFR part 860-892 and product code classification files in U.S., and EMDN in Europe as basic data to compare medical device products and derive medical devices with different management systems. As a result of comparing the definition and product classification systems of medical devices in Korea, the U.S. and Europe, medical device accessories, prosthetic limbs and aids among assistive devices for persons with disabilities, drugs, quasi-drugs and industrial products that are not managed by medical devices in Korea are managed as medical devices in the U.S. and Europe. This study aims to improve public health by securing systematic product safety management and essential performance under medical device regulations. Management within a single medical device system will increase the efficiency of licensing work of domestic medical device manufacturers and related organizations. It is also expected to help advance the system according to the international harmony of the item classification system and enhance smooth import and export competitiveness.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.3
• /
• pp.59-71
• /
• 2020

This study is empirically intended to look into the effects of smart factory technologies on quality and innovation performance in small and medium-sized Enterprises(SMEs). The research results are as follows. Device and application technologies for smart factory had a positive effect on the information quality and system quality, while platform technologies had an insignificant effect on the information quality and system quality, rejecting the effect of platform technologies for smart factory on information quality and system quality. Device technologies for smart factory had also a significant effect on innovative performance, while platform and application technologies had an insignificant effect on innovative performance, rejecting the effect of platform and application technologies for smart factory on innovative performance. The system quality had a significant effect on innovative performance, while the information quality had an insignificant effect on innovative performance. The quality played a partial mediating role in the effect of device technologies for smart factory on innovative performance. These results indicate that small and medium-sized venture firms should implement a high standard of information quality management(IQM) through interconnection as the kernel of a smart factory in the 4th revolutionary era, and that they can improve their corporate performance through the interlocking between components from manufacturing design to execution and analysis and the integrated management of systematic information collected from devices if necessary.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.6
• /
• pp.957-962
• /
• 2013

This paper presents a performance testing device for safety fences of domestic professional baseball stadiums. Safety fences of professional stadiums have been fabricated and installed without adhering to any safety regulations, safety fences demonstrate critically low safety performances and many outfielders are severely injured every season. In this study, we designed and fabricated a performance testing device for safety fences and investigated its validity and reproducibility. A HIC (head injury criterion) was used for the statistical analysis of colliding data. We found that the optimal expulsion pressure and eliminated the accelerometer by replacing it with a velocity sensor using an estimation of the correlation between the momentum data obtained from velocity sensor and the impulse data from the accelerometer.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.10 s.253
• /
• pp.957-965
• /
• 2006

A high-performance hot chuck is designed as a heating device for an ultra-precision flip-chip bonder with infrared alignment system. Analysis of design requirements for thermal performance leads to a radiative heating mechanism employing two halogen lamps as heating source. The heating tool is made of silicon carbide characterized by high thermal diffusivity and small thermal expansion coefficient. Experimental tests are performed to assess heat-up performance and temperature uniformity of the heating tool. It is revealed that the initial design of hot chuck results in a good heat-up speed but there exist a couple of troubles associated with control and integrity of the device. As a means to resolve the raised issues, a revised version of heating tool is proposed, which consists of a working plate made of silicon carbide and a supporting structure made of stainless steel. The advantages of this two-body heating tool are discussed and the improved features are verified experimentally.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.445-447
• /
• 2016

Performance comparison between Tunneling Field-Effect Transistors (TFETs) was examined when three types of device parameter of double-gate TFET (DG-TFET) and single-gate TFET (SG-TFET) are varied. When the channel length is over 30 nm, silicon thickness is below 20 nm, and a gate insulator thickness decreases, the performance of $I_{on}$ and SS in SG-TFETs and DG-TFETs enhances. It shows that the performance of the DG-TFETs is improved than that of SG-TFETs at three types of device parameter.

• ETRI Journal
• /
• v.44 no.3
• /
• pp.450-461
• /
• 2022

The Gen-Z protocol is a memory semantic protocol between the memory and CPU used in computer architectures with large memory pools. This study presents the implementation of the Gen-Z hardware system configured using Gen-Z specification 1.0 and reports its performance. A hardware prototype of a DDR4 Gen-Z memory pool with an optimized character, a block device driver, and a file system for the Gen-Z hardware was designed. The Gen-Z IP was targeted to the FPGA, and a 512 GB Gen-Z memory pool was configured on an ×86 server. In the experiments, the latency and throughput of the Gen-Z memory were measured and compared with those of the local memory, SATA SSD, and NVMe using character or block device interfaces. The Gen-Z hardware exhibited superior throughput and latency performance compared with SATA SSD and NVMe at block sizes under 4 kB. The MySQL and File IO benchmark of Gen-Z showed good write performance in all block sizes and threads. Besides, it showed low latency in RocksDB's fillseq dbbench using the ext4 direct access filesystem.

• Structural Engineering and Mechanics
• /
• v.86 no.2
• /
• pp.249-260
• /
• 2023

The uncertainties involved in structural performances are of importance when the optimum number and property of seismic retrofit devices are determined. This paper proposes a seismic retrofit design framework for asymmetric soft-first-story buildings, considering uncertainties in the soil condition and seismic retrofit device. The effect of the uncertain parameters on the structural performance is used to find a robust and optimal seismic retrofit solution. The framework finds a robust and optimal seismic retrofit solution by finding the optimal locations and mechanical properties of the seismic retrofit device for different realizations of the uncertain parameters. The structural performance for each realization is computed to evaluate the effect of the uncertainty parameters on the seismic performance. The framework utilizes parallel processing to decrease the computationally intensive nonlinear dynamic analysis time. The framework returns a robust design solution that satisfies the given limit state for every realization of the uncertain parameters. The proposed framework is applied to the seismic retrofit design of a five-story asymmetric soft-first-story case study structure retrofitted with a viscoelastic damper. Robust optimal parameters for retrofitting a structure to satisfy the limit state for the different realizations of the uncertain parameter are found using the proposed framework. According to the performance evaluation results of the retrofitted structure, the developed framework is proved effective in the seismic retrofit of the asymmetric structure with inherent uncertainties.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1080-1084
• /
• 2011

Urban maglev should have such characteristics as not only environmentally friendliness and excellent driving capability but also curve negotiation performance because its routes have many sharp curves. Due to normal mechanism of urban maglev its relative displacements of secondary spring are bigger than conventional railway vehicle and the centering force of levitation magnet is smaller than wheel-on-rail system. These features of maglev affect the curving negotiation and so the additional steering device is to be required on Urban maglev to improve the running performance at sharp curve of less than about R50m. Some developed urban maglev had the passive steering device which consists of mechanical linkage or hydraulic cylinder and closed-route piping. But it has drawback as complexity of layout of understructure of vehicle and functional limitation of passive mechanism regarding transient curve. These demerits could be solved by using active steering system. But it has a weak point that an active device should have actuators and additional inverter or hydraulic power source. In this paper, the semi-active steering system for urban maglev is to be introduced.