• IEMEK Journal of Embedded Systems and Applications
• /
• v.15 no.1
• /
• pp.9-16
• /
• 2020

Recently, the capacity of SSD has been increasing rapidly due to the improvement of flash memory density. To take full advantage of these SSDs, first of all, FTL's prompt adaptation is necessary. The FTL is a translation layer existing in SSDs to overcome the drawback of the SSD that cannot be modified in place, and has garbage collection and caching functions in addition to the map table management function. In this study, we focus on caching function, compare and analyze the cache implementation methodologies, and propose improved methods. Typical cache implementations divide the cache into groups, manage and retrieve the caches in the group as a linked list. Thus, searches are made in the order of the linked list. In contrast, we propose a method of sequential searching using the search area group of a cache registered in the map table regardless of the linked list and cache group. Experimental results show that the proposed method has a 2.5 times improvement over the conventional method.

• Journal of Welding and Joining
• /
• v.15 no.4
• /
• pp.63-69
• /
• 1997

Welding distortion is more serious problem than any other problems caused by welding process, especially, in the heavy-industrial place. These welding distortions are caused by nonuniform heating and cooling of metal during and after welding operations. And these distortion quantities are must be known to worker in production line because distorions are important role in assembling part. Therefore an analytical model to explain and predict the welding distortion are needed. A numerical analysis of welding distortion which is inelastic behavior of weldment would require the three dimensional calculation. But computing time and memory would be very large, and the resulting cost might be unacceptable. Therefore we use a numerical technique for two dimensional analysis in the section normal to the weld direction of weldment under an assumption of quasi-stationary conditions. But the result of the calculation under two dimensional(plane strain) assumption was not satisfied as compared with experimental result. This paper proposed a technique for analysing the welding angular distortion by using a constraint boundary condition on the two dimensional finite element model. The simulation results revealed that the constraint boundary model could more reasonably describe the welding distortion than the plane strain model did.

• Journal of Korea Game Society
• /
• v.16 no.2
• /
• pp.129-138
• /
• 2016

Recently, the number of children who are required to take special care are increasing because of the fast-changing society and the environment factor. Among them, most children in poor family are leading to Children with borderline intelligence, so urgent action are needed to prevent this situation. This study is conducted to establish the reason why children with borderline intelligence are taking place. In addition, this study embodies serious game as a solution which is able to prevent and cure this children with borderline intelligence problem. This game was made to improve weak memory, concentration and judgment of children with borderline intelligence and was verified in effectiveness by thirty people and experts.

• Research in Community and Public Health Nursing
• /
• v.28 no.1
• /
• pp.98-106
• /
• 2017

Purpose: To understand the meaning of the lived experience with Person under train (PUT) for train or subway operators. Methods: The study was built on hermeneutic phenomenological themes from individual interviews of present-day train or subway operators in South Korea. Eight participants were selected to participate in the study. All qualitative data were analyzed using the heuristic guides of Van Manen. Results: Four fundamental lifeworld themes and eight sub themes emerged in the findings. The first theme of spatiality had'the place pressed by the darkness' and 'the train drags me there'. The second theme, corporeality had 'a foreboding fear', and 'debris of death that gets stuck in the whole body'. The temporality theme had'distorted time in chaos', and 'memory trapped in time'. Finally the last existential theme of relationality had 'intrapersonal encounter' and 'resentment and guilt'. Conclusion: The four existential lifeworld themes provided a framework for in-depth investigation of the operator's "lived experience." This leads to clear understanding of effects of PUT experience on related individuals. The findings imply that specific active nursing intervention strategies are necessary in order to treat affected train operators, and to prevent further issues in their work and private life.

• Korean Journal of Adult Nursing
• /
• v.14 no.4
• /
• pp.521-531
• /
• 2002

Purpose: This study was to identify the meaning of the lived experiences, to describe of the meaning structures and to develop the strategies of nursing intervention centering to these meanings of the smoking cessation. Method: This study was derived from a phenomenological analytic method suggested by Giorgi. The participants in this study were five adults who had the previous experience of smoking cessation. The data were collected from September of 2001 to April of 2002 through systemic interviews and participatory observations. Average of five interviews were performed, and each interview lasted an hour and half. Result: The meaning of smoking cessation was categorized with nine components. That is (1) obstinacy of the habit of smoking ; difficulty of endurance, succumb to temptation of smoking, repetition of smoking and smoking cessation, habit-forming. (2) Bring about a symptom of improving ; took place headache, expectoration of sputum, sense of instability. (3) Waver in worthy ; doubts about smoking cessation, ridiculed smoking cessation. (4) Be narrowed social life ; become estranged from friends. (5) Futility ; unnecessary, harm. (6) Self-repression ; occurred indomitable mind, strong will, endurance. (7) Gratification ; self-admiration, receive praise from family. (8) Delightfulness ; clean in body and clothes, be disgusted with the foul order of smoking. (9) Improvement in welfare ; a clear mind and good memory, improve in health, have a good appetite. Conclusion: The nursing intervention must be focused on these concerns to accomplish successful smoking cessation program.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.6
• /
• pp.599-607
• /
• 2000

This paper suggests an efficient reachability analysis method of bounded petri nets. Reachability analysis is a fundamental basis for studying the dynamic properties of any discrete event systems. However, it takes at least exponential execution time and memory space to verify in general petri nets. That is, state space explosion problem may occur. In this paper, we attack problems of previous approaches - state space explosion and restrictions to applicable petri net classes - by formulating the reachability problem as set operation over structural relations among places on an unfolding.

• Journal of the Korean Home Economics Association
• /
• v.40 no.7
• /
• pp.193-210
• /
• 2002

The purpose of this study is to identify the characteristics of physical setting of adult day care as a place for the elders and adult and to develop an basic understanding of the architectural program and physical setting for adult day care for the cognitively-impaired in the U.S.A. The data was collected from 13 Adult Day Care Centers(ADCC) from 2001 to 2002 by interview and the documents about those facilities. Physical environment should be viewed as an element in the care of individuals with dementia, and that the principles used to plan and design environment should be consistent with the principles used in providing other aspects of care. The results of the study provided the information about the best condition of physical setting of ADCC for the elderly with dementia. Memory Loss Adult Day Center and St. Ann Center for Intergenerational Care have better architectural program than other facilities. It is the hope of this study to provide guideline for design and care professionals with a first draft of a "sense-making" template and to slow own the progression of the disease by the appropriate physical environment.

• Korean Institute of Interior Design Journal
• /
• v.17 no.2
• /
• pp.39-46
• /
• 2008

This paper is a research about the expression and characteristics of sense space by a phenomenological approach through body from an anthropocentric point of view. The phenomenological expression elements of sense space have been abstracted by putting the characteristics of body perception into shape through the phenomenological approach. This research aims to provide the expression and characteristics of sense space that can be applied by phenomenological elements of emotional expression, and analyze their application level by phenomenological body perception in space through corresponding examples. As a result of this research, the expressions of sense space approach - such as migration of moving lines, reiteration and segmentation of region, spatial flexibility, transferal of sense, stimulation of combined senses, symbolic abstraction of memory, perception of environment and space, time by light, phenomenal water space, time expression by surrounding environments etc. - and the characteristics of sense space according to each expression have been obtained through the phenomenological expression elements in sense space such as expansive perception by consecutive scenes, spatial and sensory experience, embodiment of place, phenomenal change by time. It aims to grope for a new approach and possibility to the embodiment and expression of sense space through the expression of sense space approach based on the phenomenological body perception.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.65-69
• /
• 2004

The small form factor optical data storage devices are developing rapidly nowadays. Since it is designed for portable and compatibility with flash memory, its components such as disk, head, focusing actuator, and spindle motor should be assembled within 5 m thickness. The thickness of focusing actuator is within 2 mm and the total working range is $+/-100{\mu}m$, with the resolution of less than $1{\mu}m$. Since the thickness is limited tightly, it is hard to place the yoke that closes the magnetic circuit and hard to make strong flux density without yoke. Therefore, Halbach array is adopted to increase the magnetic flux of one side without yoke. The proposed Halbach array type focusing actuator has the advantage of thin actuation structure with sacrificing less flux density than conventional magnetic array. The optical head unit is moved on the swing arm type tracking actuator. Focusing coil is attached to swing arm, and Halbach magnet array is positioned at the bottom of deck along the tracking line, and focusing actuator exerts force by the Fleming's left hand rule. The working range and resolution of focusing actuator are analyzed with FEM and experiment.

• Structural Engineering and Mechanics
• /
• v.84 no.3
• /
• pp.323-335
• /
• 2022

The main idea of the framework is to seamlessly combine a reasonably accurate and fast surrogate model with the importance sampling strategy. Developing a surrogate model for predicting structures' dynamic responses is challenging because it involves high-dimensional inputs and outputs. For this purpose, a novel surrogate model based on cutting-edge deep learning architectures specialized for capturing temporal relationships within time-series data, namely Long-Short term memory layer and Transformer layer, is designed. After being properly trained, the surrogate model could be utilized in place of the finite element method to evaluate structures' responses without requiring any specialized software. On the other hand, the importance sampling is adopted to reduce the number of calculations required when computing the failure probability by drawing more relevant samples near critical areas. Thanks to the portability of the trained surrogate model, one can integrate the latter with the Importance sampling in a straightforward fashion, forming an efficient framework called TTIS, which represents double advantages: less number of calculations is needed, and the computational time of each calculation is significantly reduced. The proposed approach's applicability and efficiency are demonstrated through three examples with increasing complexity, involving a 1D beam, a 2D frame, and a 3D building structure. The results show that compared to the conventional Monte Carlo simulation, the proposed method can provide highly similar reliability results with a reduction of up to four orders of magnitudes in time complexity.