• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.12 s.105
• /
• pp.1378-1388
• /
• 2005

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.18 no.1
• /
• pp.25-33
• /
• 2000

In recent year, many imaging systems have been developed, and it became increasingly important to exchange image data through the computer network. Therefore, it is required to reproduce color image independently on each imaging device. However, even if the image are same, perceived color is not always same under different viewing conditions. On the other hand, even if the image are different, we want to perceive same color under different viewing conditions. Therefore we must know the spectral reflectance information of object. We measured many reflectance human skin can be estimate using only three principal component. For Munsell color patches, five principle components were necessary to estimate the reflectance spectra. For that purpose, we have developed color image acquisition system that is composed of five band filters and CCD camera. Improved spectral reflectance of object is predicted by five band images taken by color image acquisition system and then we take account of camera's noise and component of object image for predicting accurate spectral reflectance of object. In the results, we confirmed that color difference and MSE(Mean Square Error) between measured and predicted spectral reflectance of object decreased into 0.0071 and 7.72 respectively.

• MALSORI
• /
• no.53
• /
• pp.1-16
• /
• 2005

This experimental study aims to test the hypothesis that the occurrence of English sentence-final stop release is, at least, partly predictable by examining its phonetic context. 10 native(5 male and 5 female) speakers of American English recorded, in a sound-proof booth, sentences excerpted from novels and the natural documents on the World Wide Web. Based on the waveforms and spectrograms of the recorded sentences, judgements of the release of a sentence-final stop were made. If the aperiodic energy of a given final stop lasted more than .015 second, it was considered to be "released." The result reveals that English sentence-final stops tend to be released when they are 1) velar consonants, 2) preceeded by tense vowels, and 3) coda consonants of content words. The phonetic environment in which final stops are often released can be characterized by the articulatory comfortableness and the need for release burst noise, without which the final stops may not be correctly perceived. By examining the release of English final stops, it is concluded that the phonological events, which had been considered to occur rather "randomly," in fact, reflect the universal tendency of human speech: to minimize the speakers' and hearers' effort.

• Korean Journal of Human Ecology
• /
• v.10 no.4
• /
• pp.349-355
• /
• 2001

The use of bed in Korea has increased steadily, however, intensive survey on the general use and consumer's evaluation of their beds have not been performed sufficiently, yet. Thus, the purpose of this study is to investigate the actual use of the consumer and their degree of evaluation for the component of the bed as well as their feeling of discomfort on the various parts of body. More than one hundred users of commercial beds were responded to the survey. The results obtained were as follows: (1) Complaint about the depression of the mattress and the noise from the bed was apparent in the current use of beds. (2) Important physical variable related to the comfortable sensation of the sleeping was the degree of support in maintaining the natural shape of the spine and waist. Durability and the degree of hardness of the mattress were also important physical parameters of bed perceived by consumer. (3) The degree of discomfort on the back and waist during sleep was closely related to the comfort evaluation of the bed.

• Journal of the Korean housing association
• /
• v.21 no.4
• /
• pp.129-137
• /
• 2010

This study surveys the degree of residents' satisfaction on the current street space to suggest alternatives for the improvement of the street space design in detached house areas. In the results of the survey, we find the following. First, in the result of analysis on age, residential term, having children or not, income level, and type of house ownership, residents are homogeneous in social and economic characteristics. There are similarity in geographical, locational conditions, neighboring facilities, deterioration of residential house, and the time of residential formation among residential areas. Second, satisfactory determinants of residents on street space according to street types, are maintenance, protection of privacy, and parking space. Third, satisfactory determinants of residents on street hierarchy is the inner circulation road while unsatisfactory one is the inner roads. Fourth, age, residential term and type of house ownership are significant factors influencing residents' satisfaction. Factors influencing satisfaction on street space are also affecting total satisfaction and factors associated with street environment are perceived more important ones than factors associated with street activities. Thus we find the degrees of satisfaction for residents on street type and street hierarchy are different despite that general characteristics of residents are similar. We also find residents consider street noise and maintenance as critical factor among physical factors of street space.

• The Journal of the Korea Contents Association
• /
• v.19 no.9
• /
• pp.329-337
• /
• 2019

Prevention is very important in terms of the fact that the percentage of people in their 10s and 20s experience noise-prone hearing is so serious that it can lead to serious hearing later on. This study examines the effect of the hearing loss prevention public advertisement message on the hearing loss prevention intent of the acceptor according to the type of framing(positive/negative) and self-efficacy information provision (provide information/do not provide information). The perceived risk and future time orientation as individual characteristics of individual participants were set as variables that could influence the message effect. In this paper, we propose a message expression method and effective message delivery method in the aspect of message strategy and effect of execution when promoting understanding and interest in hearing loss prevention.

• Journal of muscle and joint health
• /
• v.31 no.1
• /
• pp.53-63
• /
• 2024

Purpose: This study aimed to determine the prevalence of dizziness in adults and to identify factors associated with dizziness. Methods: This cross-sectional study used secondary data from the Eighth Korea National Health and Nutrition Examination Survey. Participants included 10,265 older adults aged≥40 years. Data were analyzed using descriptive statistics, the chi-squared test, and multinomial logistic regression with the SPSS/WIN 27.0 program. Results: The prevalence of dizziness was 26.2%, with 20.9% reporting episodic dizziness and 5.3% reporting chronic dizziness. Compared to that noted in the control group participants without dizziness, the risk of episodic or chronic dizziness was higher in women and in participants with older age, low education level, low income level, high perceived stress level, depression, tinnitus, and occupational noise exposure. Moreover, the risk of chronic dizziness was higher among those with a body mass index of <25 kg/m², stroke, cardiovascular disease, or severe hearing loss. Conclusion: The study underscores the need to comprehensively identify risk factors associated with dizziness and to develop interventions to prevent and manage the occurrence and chronicity of dizziness in the general population.

• Journal of Korean Academy of Nursing
• /
• v.27 no.1
• /
• pp.178-188
• /
• 1997

As a descriptive survey, this study was attempted to get basic data necessary to recognize the factors that disturb the therapeutic atmosphere of hospital wards as perceived by nurses and hospitalized patients, to identify differences between the perceptions of the nurses and of patients. The subjects, 159 patients in Pusan National Hospital and 68 nurses working there were sampled between March 18 and April 13, 1996. The tool used to measure the disturbing factors was an amended form of the one developed by Kim, Mae Ja(1983). The differences between each subject's score for each factor were analyzed using means & SD. and the highest 3 items above the mean score for each factor were collected and compared. The results are described below : 1. Subject's perception of main disturbing factors : patients reported that the main factors were 'loss of role & economic trouble', 'the prognosis of disease', 'the change of daily life' but nurses replied that the main factors were' the prognosis of disease', 'the communication trouble with the medical team & interpersonal relationships'. 'The change of daily life' was not a perceved factor by nurses, but ranked third by the patients. 2. Subject's perception degree of each disturbing factor : (1) among the items related to interpersonal relationship. the patient group reported that the worst disturbance was dur to severely ill patients in the same room' but the nurse group regarded 'greed to monopolize wheelchairs or other supplies' as the worst disturbance. (2) among the items related to physical factors. the patient group regarded 'limitations to wash their body, physical pain and limitations in physical activity' as the worst disturbance, but the nurse group regarded' physical pain', and 'limitations to activity or change of appearance' as the worst disturbance. (3) among the items related to the change of daily activity, the patient group regarded 'the boredom of hospitalization or infavorable diet' as the worst disturbance, but the nurse group regarded 'too much noise or unclean room' as the worst disturbance. (4) among the items related to the communication trouble with medical team, the patient group regarded 'the ignorance of their disease due to poor information. the inability to understand the language of the medical team or the difficulty in seeing physician in time' as the worst disturbance, but the nurse group regarded 'the inability to trust physicians and physician's poor attention to patients' as the worst disturbance.

• 모자간호학회지
• /
• v.2 no.1
• /
• pp.45-54
• /
• 1992

The purpose of this study was to explore the stressors in pediatric intensive care unit and impaired psychological responses of children after open heart surgery. Sixteen children aged 6 to 11, who were admitted to the hospital for open heart surgery during the period from July, 1991 to February, 1992 were the subjects of the study. Observations, drawings, and interviews were used to collect data for study. Behavioral responses about intensive care unit phenomena were analyzed according to the 4 categories identified to assess children's perceived stressors in ICU. Impaired psychological responses were examined using observational and interview data. Drawings were analyzed by content and color by this researcher and validated by the psychologist. The findings were as follows : 1. The most frequently perceived stressors by children in ICU were the physical stressors causing pain and discomfort(68.5%). It was followed by social stressors which denote disruption of relationship with family and friends(13.0% ), environmental stressors which denote unfamiliar surroundings, noise, staff, and other patients (11.2%), and psychological stressors which denote factors affecting self-esteem such as inability to communicate and inadquate knowledge of the situation (7.3%). 2. 81.3% of the children showed of least one of the impaired psychological responses. Three children (18.8%) experienced time disorientation. An equal number of subject experienced perceptual illusion. Two children(12.5%) experienced hallucination. Vivid dream about ICU phenomena was reported by 2 children. Seven children(43.8%) were identified as having exaggerated fear. They feared about oxygen mask and ICU environment in general. Seven children(43.8%) experienced impairment of memory about treatments, procedures, and environment of ICU. 3. The analysis of children's drawing revealed that 56.3% of children experienced fear in the ICU. 75% of children included nurses in the drawings and 62.5% of children drew other children. 81.3% of children drew and identified himself in the drawing. The colors used most by children were green, purple, and brown. From this result, it is recommended to prepare children before open heart surgery to reduce their stressors and impaired psychological responses in ICU.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.12
• /
• pp.1166-1176
• /
• 2011

The prospect in opening the arctic trade transportation route on a year-round basis offers vast opportunity of exploring untapped resources and shortened navigational routes. In addition, the environment's remoteness and lack of technical experiences remains a big challenge for the maritime industry. With this, engine designers and makers are continually investigating, specifically optimizing propulsion shafting system design, to meet the environmental and technical challenges of the region. The International Association of Classification Society, specifically machinery requirements for polar class ships(IACS UR13), embodies the propulsion shafting design requirements for ice class vessels. However, the necessity to upgrade the various features of the unified rules in meeting current polar requirements is acknowledged by IACS and other classification societies. For the polar class propulsion shafting system, it is perceived that the main source of excitation will be the propeller - ice load interaction. The milling - and the impact load, in addition to the load cases interpreted by IACS, contribute greatly to the overall characteristic of the system and due considerations are given during the propulsion design stage. This paper will expound on the excitation load estimation factors affecting the dynamic response of the different propulsion shafting system design. It is anticipated that detailed understanding of these factors will have a significant role during propulsion shafting design in the future.