• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.2
• /
• pp.87-95
• /
• 2016

Nonvolatile memory (NVM) is being considered as an alternative of traditional memory devices such as SRAM and DRAM, which suffer from various limitations due to the technology scaling of modern integrated circuits. Although NVMs have advantages including nonvolatility, low leakage current, and high density, their inferior write performance in terms of energy and endurance becomes a major challenge to the successful design of NVM-based memory systems. In order to overcome the aforementioned drawback of the NVM, extensive research is required to develop energy- and endurance-aware optimization techniques for NVM-based memory systems. However, researchers have experienced difficulty in finding a suitable simulation tool to prototype and evaluate new NVM optimization schemes because existing simulation tools do not consider the feature of NVM devices. In this article, we introduce a NVM-based cache simulator to support rapid prototyping and evaluation of NVM-based caches, as well as energy- and endurance-aware NVM cache optimization schemes. We demonstrate that the proposed NVM cache simulator can easily prototype PRAM cache and PRAM+STT-RAM hybrid cache as well as evaluate various write traffic reduction schemes and wear leveling schemes.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.349-354
• /
• 2000

A use of Titanium alloy as a structural material is increasing lately. Among those titanium alloys, Ti-6A1-4V alloy is the most popular one with taking 2/3 of it's market. Also, Ti-6A1-4V alloy can get the stability of organization and product measure, and the evaluation of the cutting ability and the mechanical characteristics. The point in titanium alloy work is on how treat the heat generated during grinding. Because the heat conductivity of titanium alloy is unnegligibly low, the grinding heat is accumulated in workpiece, and it cause the increasing of grinding grits' wear and the rough grinding surface. So, these characteristics in grinding of titanium alloy will change the mechanical characteristics of the titanium alloy. From this study, the mechanical characteristics of annealed Ti-6A1-4V alloy after grinding was concerned with checking out the bending strength values, and the factor of the change and the difference was analyzed after analyzing the surface roughness and the image from SEM.

• Journal of the Korean Society for Precision Engineering
• /
• v.6 no.1
• /
• pp.45-51
• /
• 1989

In metal cutting various types of chips are produced in consequence of cutting conditions. According to the type of chips the cutting mechanism is to be changed. Most of the cutting theory is based on the continuous chip because of its convenient analysis, but the occurrence of the saw-toothed chip depends upon the workpiece and/or the cutting conditions, one of which is titanium alloy used widely. Nowadays titanium alloys are used widely with the rapid development of aerospace structural engineering application, whereas the theory of cutting mechanism has not been established yet, and the formatting process has not been understood satisfactorily, either. Unfortunately several misconceptions, conflicting statements and statements needing further clarifi- cation are also found. In this paper an attempt is made to clarify the formation process of saw-toothed chips which are to be produced during the orthogonal cutting process of titanium alloys. They were machined at low speed to avoid the rapid tool wear. We observed the SEM-photographs of chips taken at the quick-st- opping device. It is hoped that a rational model of the mechanics of cyclic chip formation can be developed. The results obtained are as follows. 1. When a saw- toothed chip is formed, the shear band begins at the primary shear zone and trans- fers to the free surface, so that a segment is produced and it is completed by upsetting between the formatting segment and the formatted segment. 2. As the rake angle or the clearance angle increases in the machining of the titanium alloy, the chip approaches to that of the continous type. 3. When the rake angle and the clearance angle are increased the shear energy and the unit friction energy decrease, which shows the same aspect as that of the continuous chip.

• Journal of Information Processing Systems
• /
• v.15 no.6
• /
• pp.1277-1295
• /
• 2019

With its technical development, digital printing is being universally introduced to the mass production of clothing factories. At the same time, many fashion platforms have been made for customers' participation using digital printing, and a tool is provided in platforms for customers to make designs. However, there is no sufficient solution in the production stage for automatically converting a customer's design into a file before printing other than designating a square area for the pattern designed by the customer. That is, if 30 different designs come in from customers for one shirt, designers have to do the work of reproducing the design on the clothing pattern in the same location and in the same angle, and this work requires a great deal of manpower. Therefore, it is necessary to develop a technology which can let the customer make the design and, at the same time, reflect it in the clothing pattern. This is defined in relation to the existing clothing pattern with digital printing. This study yields a clothing pattern for digital printing which reflects a customer's design in real time by matching the diagram area where a customer designs on a given clothing model and the area where a standard pattern reflects the customer's actual design information. Designers can substitute the complex mapping operation of programmers with a simple area-matching operation. As there is no limit to clothing designs, the variousfashion design creations of designers and the diverse customizing demands of customers can be satisfied at low cost with high efficiency. This is not restricted to T-shirts or eco-bags but can be applied to all woven wear, including men's, women's, and children's clothing, except knitwear.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.5
• /
• pp.35-40
• /
• 2010

NAND flash memory has been widely used than traditional HDD in PDA and other mobile devices, embedded systems, PC because of faster access speed, low power consumption, vibration resistance and other benefits. DiskSim and other HDD simulators has been developed that for find improvements for the software or hardware. But there is a few Linux-based simulators for NAND flash memory and SSD. There is necessary for Windows-based NAND flash simulator because storage devices and PC using Windows. This paper describe for development of simulator-NFSim for FTL performance analysis in NAND flash. NFSim is used to measure performance of various FTL algorithms and FTL wear-level. NAND flash memory model and FTL algorithm developed using Windows Driver Model and class for scalability. There is no need for another tools because NFSim using graph tool for data measure of FTL performance.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.3
• /
• pp.99-118
• /
• 2004

The aim of this study is to evaluate tennis shoes's plantar pressure distribution in tennis prayers and to determine the influence of the shoe on various tennis movements. When investigating the biomechanics of movement in tennis, one of the first things to do is to understand the movement patterns of the sport, specifically how these patterns relate to different tennis shoes. Once these patterns are understood, footwear company can design tennis shoes that match the individual needs of tennis players. Plantar pressure measurement is widely employed to study foot function, the mechanical pathogenesis for foot disease and as a diagnostic and outcome measurement tool for many performance. Measurements were taken of plantar pressure distribution across the foot and using F-Scan(Tekscan Inc.) systems respectively. The F-Scan system for dynamic in-shoe foot pressure measurements has enabled us to assess quantitatively the efficacy of different types of footwear in reducing foot pressures. The Tekscan F-Scan system consists of a flexible, 0.18mm thick sole-shape having 1260 pressure sensors, the sensor insole was trimmed to fit the subjects' right, left shoes. For this study 4 university male, high level tennis players were instructed to hit alternated forehand stroke, backhand stroke, forehand volley, backhand volley, smash, service movement in 4 different tennis shoes. 1. When impact in tennis movement, peak pressure distribution of landing foot displayed D>C>B>A, A displayed the best low pressure distribution. A style's tennis shoes will suggest prayer with high impact. If prayer with high impact feeling during pray in tennis wear A style, it will decrease injury, will have performance improvement. 2. When impact in tennis movement, plantar pattern of pressure distribution in landing foot displayed B>A>C>D in stability performance. During tennis, prayer want to stability movement suggest B style tennis shoes when tennis movement impact keep stability of human body. B style tennis shoes give performance improvement 3. When impact in tennis movement, plantar pattern of center of force(C.O.F.)trajectory in landing foot analyzed this : 1) When stroke movement and volley movement in tennis, prayer better to rearfoot movement. 2) when service movement, prayer midfoot strike movement. 3) when smash movement, prayer have forefoot strike movement.