• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.57-63
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• 1984

To assess the hearing conservation by the hearing protection devices in the field, 1,237 healthy female weavers of 16 to 24 year old were surveyed from April 1982 to January 1983. By reviewing the charts, their working durations, hearing threshold shift levels and whether wearing the ear plugs or not were checked. The hearing threshold levels were measured at 4,000Hz by audiometry AA-30A, RION Japan. They were divided into two groups: an experimental group with ear plug and the control group without it. The threshold shift level above 40dB in controls was 44.6% in left and 40.9% in right ear and that in experimental group 8.0% in left and 6.6% in right ear. The distribution of threshold shift levels between control and experimental group was significantly different in both ears, but that between left and right ear not significantly different in both groups. The longer the working durations were, the more the proportion of high threshold shift levels was and the larger the differences in the proportion of above 40dB between both groups were.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.457-466
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• 1997

We developed a new hearing aid telephone which helps the hearing impaired person to improve the listening ability of telephone speech. Recently, the hearing impaired person and the elderly who has hearing loss have been continuously increased and their desire for participating society as a producer has been increased also. So they strong1y want the hearing aid devices which make compensation fortheir handicap. The hearing aid telephone is one of the basic aid devices that helps the hearing impaired to communicate well with other poeple and to acquire easily useful information through the phone. We analyze the hearing ability of the hearing impaired, design the new model of the hearing aid telephone and test the telephone in three fields-electrical, word perception, user test. Our new tolephone has lour band pass filter channels and the center frequencies of these filters are 500, 1000, 2000, 3000Hz which are considered psychoacoustic factors and telephone line characteristics. The hearing impaired can adjust the total gain characteristics of receiving sound to his hearing ability by setting four volumes in the telelphone. This procedure is called fitting which is a very important factor for the hearing impaired to take meaning of speech. The total gain of this telephone is over 20dB from 250Hz to 3200Hz range. From the results of the tests we certify that our new model is better for the hearing impaired to understand the meaning or telephone speech than the old general models. The next step of developing the hearing aid telephone is to study about compressing sidetone and noise, dividing frequency bands, selecting hearing aid pattern and compensating psychoacoustic loudness. we expect that the advanced hearing aid telephone can be developed by the research about speech perception characteristics of the hearing impaired in engineering and clinical side.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.155-159
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• 2009

Sudden idiopathic sensorineural hearing loss is a disease that develops within several hours to several days. Its etiology has not yet been verified, but the disturbance of the circulation of blood in the inner ear, inner-ear hydrops, and viral infection are considered possible causes of the disease. This study was conducted to evaluate the effect of Panax ginseng extract, which is known to have a vasodilatory effect, on sudden sensorineural hearing loss. Sixty-nine patients suffering from sudden sensorineural hearing loss were admitted to Korea University Anam Hospital from March to December 2008. They were divided into the experimental (30 ears) and control (39 ears) groups. Ginseng extract (2700 mg/day, 4 weeks) was added to the therapeutic regimen in the experimental group. The effect of ginseng extract therapy was analyzed according to the factors relating to the prognosis. A considerable hearing improvement was documented in both groups (32.2 dB in the experimental group and 25.8 dB in the control group). However, there was little beneficial effect of ginseng extract on additional hearing improvement compared with control. The total recovery rate of the experimental group (80.0%) was better than that of the control group (58.9%), and the experimental group's high-tone hearing gain at 3 kHz (29.7 dB) was better than that of the control group (21.7 dB). The results of the study suggest that the effects of ginseng therapy tend to be superior to those of the conventional therapy, but the difference between the two is not statistically significant. The hearing gains tend to be in the higher frequencies and may be due to the promotion of cellular differentiation from the supporting cells.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.5.2-5
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• 1977

Many persons, both children and adults, suffer from impaired hearing. The handicaps that arise from this are economic, educational and above all, social. These persons need help, both medical and educational. In order to plan facilities for the medical treat ment, the rehabilitation, and the special education required by those with impaired hearing, we must know how many persons with hearing problems there are and the severity of their handicaps. The first step in knowing these is to devide hearing impairent into categories of handicap. Historically, since Beasley (1940) proposed progressive stages of deafness in terms of social disability, there was no well organized classification. of hearing handicap except related material from Huzing (1959) and Silverman (1960). In 1965, Goodman advocated a guide hearing threshold levels and degres of relating hearing impairment. During recent one year, on the bases of Goodman classification of hearing impairment and the report from Illinois Comission on children (1968), we have studied about hearing handicaps and speech life for the 180 cases, who visited to our otolaryngology department with hearing impairment. Now, we report the results of study with the referred references.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.138-145
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• 2015

Although it is well-known that environmental noise can lead to hearing loss in individuals, the true extent of subway noise effects in the general population remains poorly understood. The purpose of the present study is to see changes of acoustic reflex thresholds and speech perception scores when passengers listen to music presented from their personal listening device in the subway. Forty subjects with normal hearing participated being divided into two groups, experimental and control groups. As a baseline, all subjects were measured by acoustic reflex thresholds in five test frequencies and Korean speech perception in noise (KSPIN) test at 0 and -5 dB SNR. In the experiment, the control group read newspaper or magazine in the subway noise, whereas the experimental group listened to music presented from their smartphone under the subway noise through speakers at 73.45 dBA for 60 min. After completing the experiment, two groups also conducted both acoustic reflex thresholds and KSPIN tests in the same condition as the baseline. The results showed that there was a significant difference of correct percent in speech-in-noise test between experimental and control groups and of that between two signal-to-noise ratios, which means the double noise exposure of 60 min might cause some degradation of speech perception when noise increases compared to only subway noise condition that was not statistically significant difference. We concluded that a risk of some degraded speech perception ability would be expected when passengers have a habit of listening to music in the subway noisy situation for a long duration.

• 월간산업보건
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• s.5
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• pp.4-15
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• 1988

In order to proffer the fundamental data for the better working environment and the effective establishment of hearing conservation program on workers exposed to industrial noise, author assessed noise levels on the 42 noisy processes among 84 manufactures of 9 industries and measured noise gearing loss by the type of industries on 3,104 workers at these noisy processes from March, 1986 to Februry, 1987. The results were summarized as follows: 1. The averge of A-weight sound level of 23 processes(54.8%) and the avergae of sound level at each octave band of 14 processes(33.3%) exceeded the permissible exposure limits in 8 hours per day. 2. The noise level was the highest in process of cocking of ship building(109.1dBA), and followed by plating of steel rolling(104.3dBA), rivet of manufacture of motor vehicles(102.5dBA), shot of ship building(98.5dBA), aciding(95.7BA) and steel tubing(95.0dBA) of steel rolling, weaving of textiles(95.0dBA). 3. The permissible exposure time for the average of sound level at each octave band was only 30 minutes in the process of cocking of ship building, plating of steel rolling and rivet of manufacture of motor vehicles. 4. As a result of audiometric examination in 3,104 workers, the rate of hearing loss over 50dB at 4,000Hz was 7.3%(227 workers) and the rate of hearing loss over 41dB at 60average method was 2.9%(89 workers). 5. The prevalence of occupational hearing loss in ship building and manufacture of motor vehicle was 5.2% and it was the highest among prevalence of these 9 industries. 6. As a result of this suvery, the noise control and gearing conservation program were required especially in the industry of ship building and manufacture of motor vehicle.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.145-150
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• 2010

Acrodysostosis is an extremely rare disorder characterized by short fingers and toes with peripheral dysostosis, nasal hypoplasia, and mental retardation. We report a 16-year-old Korean boy with acrodysostosis who had characteristic clinical features and cervical spine stenosis manifested by neurologic symptoms. On presentation, he complained of difficulty in raising his arms, and suffered from intermittent pain and weakness in both upper extremities. He had short stature and dysmorphic facial features, including a broad, depressed nasal bridge, small, upturned nose, bilateral epicanthal folds, and mild hypertelorism. Moderate mental retardation and sensorineural hearing loss in both ears were also present. Radiological findings included broad, short metacarpals and phalanges with cone-shaped epiphyses, bilateral Madelung deformities, hypertrophied first metatarsals, and thickening of the calvarium. Magnetic resonance imaging findings included stenosis of the cervical spine, platybasia with compression into the cervicomedullary junction, and downward displacement of the cerebellar tonsils. Here, we report a case of acrodysostosis with symptoms and signs of cervical spinal stenosis first in Korea. If it is diagnosed in the early stages, possible life-threatening complications, including spinal canal stenosis, can be managed properly and permanent neurologic sequelae might be avoided. Therefore, it is important to consider acrodysostosis in the differential diagnosis of peripheral dysostosis.

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.38-48
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• 2006

For extending of hot-spot of WLAN, (2) proposes internetworking scheme between wireless LAN (WLAN) and mobile ad-hoc network (MANET), which employ the same layer-2 protocol with different mode. Compared to internetworking schemes between UMTS (Universal Mobile Telecommunications Systems) and WLAN (3-4), the scheme from (2) has relatively low overhead and latencies because WLAN and MANET are physically and logically similar to each other. However, the mode switching algorithm proposed in r2] for internetworking between WLAN and MANET only considers signal strength and determines handoff, and mobile nodes following a zigzag course in pollution area may perform handoff at short intervals. Furthermore, (2) employs mobile IPv6 (MIPv6) at base, which brings still high delay on handoff and overhead due to signal message exchange. In this paper, we present optimized internetworking scheme between WLAN and MANET, modified from (2). To settle ping-pong handoff from (2), we propose adaptive mode switching algorithm. HMIPv6 is employed for IP connectivity and mobility service in WLAN, which solves some shortcomings, such as high handoff overhead and vulnerable security. For routing in MANET, OLSR is employed, which is a proactive Protocol and has optimally reduced signal broadcasting overhead. OLSR operates with current P protocol compatibly with no change or modification. The proposed internetworking scheme based on adaptive mode switching algorithm shows better performance than scheme from (2).

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.1
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• pp.141-153
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• 2003

Introduction : The causes of sudden sensorineural hearing loss have not been detemined with precision until recently, but viral infections and vascular insufficiencies, such as vascular spasm, occlusion of sludging of erythrocytes were considered as major factors. The treatment has not been determined with precision until recently. It is similar to dizziness(眩暈). sudden dcafncss(暴聾) and congestion-fire deafness(痰火聾) in Oriental Medicine. It is very rare that someone has sudden hearing loss and visit Oriental Medicine Clinic right that time. But we expect if they take a Oriental treatment on thc right time. more effective for their symptom. Subjects : Following conclusions were reached by measuring results of oricntal medical treatments for 40 patients who visited the clinic between January of 2000 and December of 2002, and received treatments continuously for more than 1 months of time. Methods : Among the selected 40 patients. 30 patients belong to Group Ⅰ, which consisted of patients who had already visited a general hospital prior to visiting this clinic, achieved no recovery at all from sudden deafness despite going through more than 5 days of hospitalized treatments of steroidal medications. Group Ⅱ was consisted of 10 patients of sudden deafness who did not experience any steroidal treatments from other hospital prior to the oriental medical treatment. Results and conclusion : According to differentiation of syndrome. among 30 patients of the Group Ⅰ. 21 were categorized as excess syndrome patients and remaining 9 as deficiency syndrome paticnts. Among 10 patients of For Group Ⅱ, 5 were excess syndrome patients and remaining 5 were deficiency syndrome patients. Among Group Ⅰ, recovery ratio of excess syndrome patients was 47.7$\%$ and deficiency syndrome patients was 44.4$\%$ adding up recovery ratio of the group to be 46.1$\%$. Among Group Ⅱ, recovery ratio of excess syndrome patients was 80$\%$ and deficiency syndrome patients was 100$\%$ adding up recovery ratio of the group to be 90$\%$. Oriental medical treatments are generally more effective(90$\%$ recovery ratio) for Sudden Deafness than steroidal treatments. Oriental medical treatments are almost equally effective for both excess syndrome patients and deficiency syndrome patients. However, steroidal treatments for excess syndrom patients(45$\%$ recovery ratio) is much less effective than deficiency syndrome patients(73$\%$ recovery ratio). This indicates that steroidal treatments should be applied selectively to deficiency syndrome patients if applied at all. Even for patients with sudden deafness which hospitalized steroidal treatments did not result in any recovery at all, oriental medical treatments were able to achieve 46.1$\%$ recovery ratio.

• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.113-122
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• 2018

Purpose: The aim of this study was to evaluate the clinical characteristics of children diagnosed as cryopyrin-associated periodic syndrome (CAPS) in Korea. Methods: Diagnosis was made based on clinical features and confirmed by a mutation in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene. Especially, osteocartilaginous overgrowth in the patella or distal femur was so characteristic that its presence warranted a diagnosis of chronic infantile neurologic cutaneous and articular/NOMID. Results: We observed the clinical features of 9 Korean CAPS patients. All the patients suffered from an urticarial rash with recurrent fever. Among the 9 patients, 6 presented with rash and 4 with fever on the 1st or 2nd days of birth. Eight patients showed myalgia, and 7 patients showed arthralgia in the joints, and 6 patients showed radiologic findings of arthropathy including cupping of the metaphysis, excessive growth of the epiphysis, osteopenia or overgrowth of the cartilage. Four patients showed brain atrophy, enlarged ventricles or leptomeningeal enhancement on magnetic resonance imaging. Intellectual disability was observed in 1 patient. Five patients had eye involvement as conjunctivitis, uveitis, chorioretinitis, avascular area or papillary edema, and 3 patients showed progressive hearing loss. All 9 patients showed increased C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Conclusions: All the patients carried a mutation on exon 3 of the CIAS1 gene. After the anakinra (interleukin-1 receptor antagonist) therapy, the fever and rash immediately disappeared, and CRP and ESR were improved.