• Bulletin of the Korean Chemical Society
• /
• v.23 no.3
• /
• pp.447-453
• /
• 2002

In this paper we have presented the results of thermodynamic, structural, and dynamic properties of model systems for liquid benzene, toluene and p-xylene in an isobaric-isothermal (NpT) ensemble at 283.15, 303.15, 323.15, and 343.15 K using molecular dynamics (MD) simulation. This work is initiated to compensate for our previous canonical (NVT) ensemble MD simulations [Bull. Kor. Chem. Soc. 2001, 23, 441] for the same systems in which the calculated pressures were too low. The calculated pressures in the NpT ensemble MD simulations are close to 1 atm and the volume of each system increases with increasing temperature. The first and second peaks in the center of mass g(r) diminish gradually and the minima increase as usual for the three liquids as the temperature increases. The three peaks of the site-site gC-C(r) at 283.15 K support the perpendicular structure of nearest neighbors in liquid benzene. Two self-diffusion coefficients of liquid benzene via the Einstein equation and via the Green-Kubo relation are in excellent agreement with the experimental measures. The self-diffusion coefficients of liquid toluene and p-xylene are in accord with the trend that the self-diffusion coefficient decreases with increasing number of methyl group. The friction constants calculated from the force auto-correlation (FAC) function with the assumption that the fast random force correlation ends at time which the FAC has the first negative value give a correct qualitative trends: decrease with increase of temperature and increase with the number of methyl group. The friction constants calculated from the FAC's are always less than those obtained from the friction-diffusion relation which reflects that the random FAC decays slower than the total FAC as described by Kubo [Rep. Prog. Phys. 1966, 29, 255].

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.99-106
• /
• 2017

With the increased interest in the quality of life of modern people, the implementation of the five-day working week, the increase in traffic convenience, and the economic and social development, domestic and international travel is becoming commonplace. Furthermore, in the past, there were many cases of purchasing packaged goods of specialized travel agencies. However, as the development of the Internet improved the accessibility of information about the travel area, the tourist is changing the trend to plan the trip such as the choice of the destination. Web services have been introduced to recommend travel destinations and travel routes according to these needs of the customers. Therefore, after reviewing some of the most popular web services today, such as Stubby planner (http://www.stubbyplanner.com) and Earthtory (http://www.earthtory.com), they were supposed to be based on traditional Traveling Salesman Problems (TSPs), and the travel routes recommended by them included some practical limitations. That is, they were not considered important issues in the actual journey, such as the use of various transportation, travel expenses, the number of days, and lodging. Moreover, although to recommend travel destinations, there have been various studies such as using IoT (Internet of Things) technology and the analysis of cyberspatial Big Data on the web and SNS (Social Networking Service), there is little research to support travel routes considering the practical constraints. Therefore, this study proposes a new mathematical model for applying to travel route recommendation service, and it is verified by numerical experiments on travel to Jeju Island and trip to Europe including Germany, France and Czech Republic. It also expects to be able to provide more useful information to tourists in their travel plans through linkage with the services for recommending tourist attractions built in the Internet environment.

• International Journal of High-Rise Buildings
• /
• v.11 no.4
• /
• pp.347-362
• /
• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.14 no.1
• /
• pp.61-70
• /
• 2013

■ Objectives The goal of this pilot study is to observe the change of gait pattern in a patient after peroneal nerve electrical stimulation(PNST). ■ Methods We analyzed the gait pattern of stroke patient using treadmill gait analysis system before and after PNST for seven weeks. The PNST was carried out for 20minutes every day except Sunday. In addition, the measurement was carried out every Saturday. At the fifth week, the PNST was not carried out to confirm whether the effect of PNST was disappeared immediately when PNST was not applied. ■ Results After PNST, while heel contact time and heel max force increased and forefoot and midfoot max force decreased, the gait parameters such as cadence, velocity, swing phase, stance phase, total double support, step length, stride length, step time, stride time and forefoot contact time, were not changed. ■ Conclusion Gait of a patient with cerebral stroke was changed positively after PNST.

• Journal of the Korean Society for Railway
• /
• v.15 no.1
• /
• pp.48-61
• /
• 2012

It is of great importance to assure the running safety, ride comfort and serviceability in designing the floating slab track for mitigation of train-induced vibration. In this paper, for this, analyzed are the system requirements for the running safety, ride comfort and serviceability, and then, the behavior of train and track at the floating slab track including the transition zone to the conventional concrete slab track according to several main design variables such as system natural frequency, arrangement of spring at transition, spacing of spring isolators, damping ratio and train speed, using the dynamic analysis technique considering the train-track interaction. The results of this study demonstrate that the discontinuity of the support stiffness at the transition results in a drastic increase of the dynamic response such as wheel-rail interaction force, rail bending stress and rail uplift force. Hence, it is efficient to decrease the spacing of springs or to increase the spring constants at the transition to obtain the running safety and serviceability. On the other hand, the vehicle body acceleration as a measure of ride comfort is little affected by the discontinuity of the stiffness at the transition, but by the system tuning frequency; thus, to obtain the ride comfort, it is of great significance to select the appropriate system tuning frequency. In addition, the effects of damping ratio, spacing of springs and train speed on the dynamic behavior of the system have been discussed.

• Progress in Superconductivity
• /
• v.11 no.1
• /
• pp.57-61
• /
• 2009

A superconductor flywheel energy storage(SFES) system is mainly act an electro-mechanical battery which transfers mechanical energy into electrical form and vice versa. SFES system consists of a pair of non-contacting High Temperature Superconductor (HTS) bearings with a very low frictional loss. But it is essential to design an efficient HTS bearing considering with rotor dynamic properties through correct calculation of stiffness in order to support a huge composite flywheel rotor with high energy storage density. Static properties of HTS bearings provide data to solve problems which may occur easily in a running system. Since stiffness to counter vibration is the main parameter in designing an HTS bearing system, we investigate HTS bearing magnetic force through static properties between the Permanent Magnet(PM) and HTS. We measured axial / radial stiffness and found bearing stiffness can be easily changed by activated vibration direction between PM and HTS bulk. These results are used to determine the optimal design for a 10 kWh SFES.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.5
• /
• pp.903-909
• /
• 2010

ADAS is the air defense control system performing air surveillance and identification of ROK and near air. This system is self-developed by Air Force, currently operated successfully as the alternative system of MCRC. ADAS processes converting and combining transferred the real time radar data detected by radars. additionally, it displays significant radar data as producing in tracks. Then, it uses the message queue for IPC(Inter Process Communication). the various tactical data processed in the server is ultimately send to the network management process through the message queue for transmitting to the weapon director console. the weapon director receives this transmitted tactical data through the console to execute air defense operations. However, there is a problem that data packet is delayed or lost since the weapon Director does not receive as the amount of tactical data from the server overflowed with air tracks and missions increased. This paper improved the algorism to display and transmit the various tactical data processed from ADAS server to numbers of the weapon director console in the real time without any delay or lost. Improved the algorism, established at exercise, the development server in the real operation network and the weapon director console, is proved by comparing the number of sending tactical data packets in the server and receiving packets in the weapon director.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.1
• /
• pp.336-342
• /
• 2021

Japanese imperialism initiated the Sino-Japanese War in 1937 and promulgated the Total National Mobilization Act in 1938, establishing a wartime total mobilization system. In the beginning of the wartime general mobilization system, Japanese colonialism focused on women's labor force and mobilized women both domestically and abroad. Women were forcibly mobilized to the Labor Patriotism Unit and Jeongshindae(Korean Women Labor Corps). Women had to take the place of home work as well as the work of men who had already been mobilized, and at the same time faced a poor situation of being forced to mobilize for war. The mobilization of Jeongshindae took place in various forms, such as recruitment, voluntary support by government offices, propaganda through schools or groups, job fraud, coercion or threats. Jeongshindae which was a representative victim of the forced mobilization of women during the Japanese colonial period, was individually litigated and remains an unresolved problem. In order to uncover the reality of the forced mobilization of women during the wartime general mobilization system, continuous research and social education through related organizations are required.

• Convergence Security Journal
• /
• v.22 no.5
• /
• pp.127-134
• /
• 2022

Although the Korea National Guard(KNG) has a short history, it has a great meaning in that it is the first of the Korean reserve forces system. Research on the KNG has been passively conducted so far. Even so, the research conducted was limited to a fragmentary description from a historical point of view and did not identify the characteristics of the KNG. Therefore, in this study, after examining the background of the times when the KNG existed, we tried to identify the characteristics of the KNG from a new perspective from legal, institutional, military, and political perspectives. In summary, the KNG was born as an efficient system in preparation for war while receiving legal support. In addition, the adoption of the volunteer army system, a recruiting system of advanced countries, the fact that officers were trained through a separate military academy unique to the KNG, and that they contributed to rear area operations are highly evaluated from a military standpoint. On the other hand, it is negative that politicians and non-military groups colluded from the process of establishing the KNG. Finally, with this study as an opportunity, it is hoped that research on the reserve force that existed before the Korean War will become more active.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.6
• /
• pp.1500-1517
• /
• 2024

With the rapid development of the tourism economy, large-scale construction of tourist attractions to achieve resource utilization and ensure the healthy development of the tourism industry has become a hot topic. However, there are still issues with resource utilization and coordinated management in the economic development of the tourism industry, which in turn affects the coordinated development of the tourism industry economy. Therefore, this study utilizes self-organization theory to explore the structure, organizational mechanism, conditional driving force of evolution, and evolutionary operation mechanism of the tourism system, analyze the current tourism situation in Hunan Province and related regions, and construct a self-organization evolution model of the tourism system. The result shows that the cumulative variance contribution rate of tourism areas in Hunan Province is 78.8%, with Zhangjiajie having the highest industrial management factors and tourism resource levels in the province, with 1.6 and 3.2 respectively. Hunan Province has abundant tourism resources but overall uneven development, with a comprehensive score of -1.03. Therefore, it is necessary to leverage the coordination advantages of various departments and industries to promote sustainable and healthy development of tourism areas. The self-organizing evolution of the tourism system not only discovers the current problems of the tourism industry, but also provides theoretical support and mechanism suggestions for the tourism system.