• Archives of Plastic Surgery
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• v.48 no.2
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• pp.224-230
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• 2021

Background Little is known about the sensate recovery of skin grafts over free non-neurotized muscle flaps. The aim of this study was to evaluate the sensitivity of free gracilis muscle flaps and meshed skin grafts without nerve coaptation. Methods Thirteen consecutive patients with a median age of 55 years (range, 21-70 years) who underwent lower extremity reconstruction between September 2014 and October 2016 were included. Complications, flap contour, skin perception, and sensate recovery were assessed. Results All flaps survived completely. In one patient, wound dehiscence and infection occurred 1 month after surgery. After a median follow-up of 14 months (range, 10-51 months), a satisfactory contour and skin perception were achieved. The Semmes-Weinstein (SW) monofilament test (154.8±22 g) and static two-point discrimination (2-PD) (12.6±0.7 mm) showed intermediate recovery compared to the surrounding site (41% and 76%, respectively). There was an intermediate correlation between flap size and sensate recovery (2-PD: r=0.27, P=0.36; SW test: r=0.45, P=0.12). Vibration sensation recovered to 60%, whereas thermal sensation remained poor (19% at 5℃ and 25% at 25℃). Conclusions Finer sensation could be partially restored. However, thermal sensation remained poor.

• Journal of Urban Science
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• v.10 no.1
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• pp.29-37
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• 2021

The number of old buildings older than 30 years in Korea continues to increase from 29.9% in 2005 to 38.8% in 2020. Considering the growing urban regeneration projects, urban maintenance projects, the suppression of urban expansion, and the lack of idle land in the city, the dismantling of old buildings is expected to increase further in the future. As major accidents at building dismantling sites continue to occur, related agencies are also strengthening safety management of building dismantling works. While physical safety management such as collapse and fall is strengthened, there is a relative lack of interest in the health of workers at dismantling sites due to environmental hazards. Since relevant laws stipulate that construction waste should be separated and discharged, old buildings need to be considered for environmental hazards such as fine dust, floating bacteria, and floating molds when dismantling. In this study, we intend to find important safety management elements in the management of building dismantling sites, measure environmental factors harmful to dismantling workers, and present basic data for the management of dismantling sites in the future. "Safety management" was the highest priority, followed by "dust," "vibration," "noise," "bacteria," and "smell." The perception of the importance of "physical damage prevention" with workers working on dismantling and managers managing the site came out similar, but the perception of "work efficiency" and "health disorder prevention" through environmental hazard management showed different priorities. In the process of dismantling, floating bacteria and floating mold were collected, cultured, and measured the concentration in the indoor air. The measurement was measured by dividing it into pre-dismantling and during dismantling.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.616-621
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• 2006

A began of this study is to verify Spontaneous Acoustic Field Reproduction System(SAFRS), developed as an embodiment of creating agreeable sound environment, with evaluation on the field application. SAFRS is a system to sense changes of surroundings and produce sounds, which can go well with environment elements sensed by the system in to the space. The sound which can go well with environment elements is sound which judged by individual evaluation to be so, the classification of the preferred sounds according to the mood of the space was suggested in the former study. So, SAFRS was applied into the Square of D University to evaluate effectiveness of the system. The executed evaluations were 1) evaluation on sounds perception, frequency, volume and matchability with the space, 2) image evaluation on the square and sound environment and 3) evaluation on sound environment with existing sounds, fountains sound, sound produced by SAFRS, and both fountains sound and sound produced by SAFRS. Verifying SAPRS of field application was deduced from those evaluations. Theresultsofthestudyarefollowing: Though the system was applied into the space, the volume of the sounds shouldn't be too high. And with visual surroundings, the effectiveness of the system would be increased. At the results of four evaluations, the result of day evaluation is; both fountains sound and sound produced by SAFRS>fountains sound>sound produced by SAFRS>existing sounds, the result of night evaluation is; sound produced by SAFRS>both fountains sound and sound produced by SAFRS>fountains sound>existing sounds and these results pointed out that sounds environment produced by the system was highly evaluated due to less background sounds.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.4 s.121
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• pp.289-297
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• 2007

SAFRS is the system designed to reproduce the harmonic sound into the space according to the environmental factors. Here the harmonic sound means the sound which judged by the subjective tests, and the methods were suggested in the former studies. In this research, SAFRS was applied into the Square of D University to evaluate and verify the effectiveness of the system and a few evaluations were carried out as follows; 1) sound perception, frequency, volume and harmony with the space, 2) images of the square and acoustic environment and 3) acoustic environment with existing sounds, fountain sound, produced sound by SAFRS, and both of them respectively. The results can be summarized as follows; 1) According to the evaluation on acoustic environment, no relationships were shown between the cognition of sounds produced by SAFRS and the frequency or volume, but inverse proportion was shown between the volume and special harmony. 2) As the result of image evaluation. the relationship between space and sound image was shown proportional only except the evaluation on main road at night time, it means that the sound proposal with the visual contents matching with the sounds would be more effective than the proposal of sound only. 3) Results of evaluation on acoustic environment showed that the cognition effect at night time was shown higher than that of day time when only the acoustic element was given and the effect was increased when the visual elements matches with the acoustic elements if both of them were given. It confirmed the harmony between visual and acoustic elements was very important.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.3 s.120
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• pp.241-248
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• 2007

A study has been conducted to investigate the subjective responses of loudness and annoyance according to the exposed time of urban traffic noise in controlled laboratory environment. To make a closer inspection into psychological response relevant to noise characteristics while varying the time of exposure to noise, the subjects were presented a set of noises with different exposed time and requested to judge spontaneously on a 100-unipolar scale. To be concrete, the subjects were exposed to noises being varied in time from 15 sec up to max. 1,200 sec for the controlled traffic noise sources. So far achieved from laborious tests, it has an importance being on the logarithmic relations of perceived loudness and exposed time, say, it is more increased the perceived loudness in the sorter exposed time than in the longer exposed time. However, the trend is said to be not effective for the case of annoyance. On the other hand, the subjective impressions on relative annoyance of noise is shown to be correlated with the noise characteristics such as loudness (sones), tonality and time with logarithmic scale, the product correlation moment being calculated as $R^{2}=0.99$. The variances to be explained for annoyance assessments through varying the time of exposure were ranged between 30 % and 50% for the exposed time, $27{\sim}37%$ for tonality, and $34{\sim}20%$ for loudness, respectively With these results, hopefully, it can be helpful for those who want to work out an experimental design for evaluating an environmental noise or to quantify any psychological dimensions found in annoyance assessments.

• International Journal of High-Rise Buildings
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• v.4 no.1
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• pp.1-8
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• 2015

A team of researchers and practitioners were recently assembled to prepare a monograph on "Wind-Induced Motion of Tall Buildings: Designing for Habitability". This monograph presents a state-of-the-art report of occupant response to wind-induced building motion and acceptability criteria for wind-excited tall buildings. It provides background information on a range of pertinent subjects, including: ${\bullet}$ Physiological, psychological and behavioural traits of occupant response to wind-induced building motion; ${\bullet}$ A summary of investigations and findings of human response to real and simulated building motions based on field studies and motion simulator experiments; ${\bullet}$ A review of serviceability criteria to assess the acceptability of wind-induced building motion adopted by international and country-based standards organizations; ${\bullet}$ General acceptance guidelines of occupant response to wind-induced building motion based on peak acceleration thresholds; and ${\bullet}$ Mitigation strategies to reduce wind-induced building motion through structural optimization, aerodynamic treatment and vibration dissipation/absorption. This monograph is to be published by the American Society of Civil Engineers (ASCE) and equips building owners and tall building design professionals with a better understanding of the complex nature of occupant response to and acceptability of wind-induced building motion. This paper is a brief summary of the works reported in the monograph.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.7
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• pp.561-568
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• 2008

The quality of the automatic transmission shift for a wheel loader has been generally evaluated by driver's perception. However the subjective evaluation of the drivers is not always directly related to the shift quality. It is necessary to set up the method for an objective assessment of the shift quality. In this paper, a quantitative assessment method has been developed for the shift quality of the automatic transmission in a wheel loader. The indices for the evaluation were selected through the various tests like the acceleration and the turbine rpm as well as the subjective evaluation of the driver, and were validated by the correlation between subjective and objective assessments using a psychophysical power law. Based on this method, the shift quality of a wheel loader has been evaluated quantitatively under various shift conditions.

• Tribology and Lubricants
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• v.33 no.4
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• pp.148-152
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• 2017

The feel of writing is important to customers when they buy smart devices with stylus such as smartphones and tablet computers. With an aim to reproduce the tactile sensibility of writing instruments when people write on the glass display using a stylus, this study focuses on the frequency characteristics of writing instruments that can describe the vibrations of writing instruments sliding over counter surfaces. In addition, this study includes the effect of various factors influencing the friction of writing instruments such as lubricant, nib material, and contact type. We perform sliding experiments with six types of writing instruments and a sheet of paper to understand the relation between the friction conditions of the nib and the frequency characteristics. As this research focuses on the tactile perception of human skin when people use a writing instrument, the analysis of frequency characteristics is performed in the perceptible frequency range of mechanoreceptors in the human skin. As a result, three types of frequency characteristics are identified. Low frequency peaks are observed for a metal nib with ink; high frequency peaks are observed for a nib without ink; and, middle frequency peaks with a wide range of distribution occurs for fabric nibs with ink. Therefore, to implement the proper feel of writing, at least three types of vibrations have to be made.

• Wind and Structures
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• v.14 no.2
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• pp.113-131
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• 2011

Excessive wind-induced motion in tall buildings can cause discomfort, affect health, and disrupt the daily activities of the occupants of a building. Dynamic vibration absorbers such as the tuned mass dampers (TMDs) can be used to reduce the wind-induced motion below a specified tolerable serviceability limit state (SLS) criterion. This study investigates whether the same probability of not exceeding specified wind-induced motion levels can be achieved by torsionally sensitive structures without/with linear/nonlinear TMDs subjected to partially correlated wind forces, if they are designed to just meet the same SLS criterion. For the analyses, different structures and the uncertainty in the response, wind load and perception of motion is considered. Numerical results indicate that for structures that are designed or retrofitted without or with optimum linear TMDs and satisfying the same SLS criterion, their probability of exceeding the considered criterion is very consistent, if the inherent correlation between the wind forces is considered in design. However, this consistency deteriorates if nonlinear TMDs are employed. Furthermore, if the correlation is ignored in the design, in many cases a slightly unconservative design, as compared to the designed by considering correlation, is achieved.

• Journal of Information Processing Systems
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• v.14 no.5
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• pp.1102-1113
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• 2018

Vibrotactile feedback is widely used in designing non-visual interactions on mobile phones, such as message notification, non-visual reading, and blind use. In this work, novel vibrotactile codes are presented to implement a non-visual text reading system for mobile phones. The 26 letters of the English alphabet are formed in an index table with four rows and seven columns, and each letter is mapped using the codes of vibrations. Two kinds of vibrotactile codes are designed with the actuator's on and off states and with specific lengths (short and long) assigned to each state. To improve the efficiency of tactile perception and user satisfaction, three user experiments are conducted. The first experiment explores the maximum number of continuous vibrations and minimum vibration time of the actuator's on and off states that the human can perceive. The second experiment determines the minimum interval between continuous vibrations. The vibrotactile reading system is designed and evaluated in the third experiment according to the results of the two preceding experiments. Results show that the character reading accuracy reaches 91.7% and the character reading speed is approximately 617.8 ms. Our method has better reading efficiency and is easier to learn than the traditional Braille coding method.