• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.23-27
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• 2005

Background and Objectives : Voice disorders can cause problems in patients with benign vocal cord lesions emotionally, physically, economically and functionally. Neither subjective nor objective voice examinations can evaluate such factors adequately. The Voice Handicap Index (VHI) subjectively evaluates voice disorders in terms of physical, functional, emotional factors and measures the patient's perception of the impact of voice disorder. The purpose of this study is to evaluate the usefulness of VHI in the patients with benign vocal cord lesions. Materials and Method : The authors evaluated 37 patients who experienced laryngeal microsurgery for benign vocal cord lesions from september 2003 to August 2004. The VHI was used to measure the postoperative changes of the patient's perception and acoustic analysis and aerodynamic tests were also done. Statistical analysis was done using paired t-test and Pearson's correlation. Results : The VHI scores showed statistically significant reductions postoperatively. In acoustic analysis, jitter and shimmer had statistically significant reductions after surgery but noise-to-harmonics ratio did not. A statistically significant change in the average MFR and MPT perioperatively was found. The relationship between VHI and acoustic, aerodynamic analysis attained statistical significance. Conclusion : The VHI is a useful assessment tool to monitor the patient's self-perception of voice change after the surgery of benign vocal cord lesions. The VHI measurement, when combined with acoustic and aerodynamic analyses, will be helpful in comparing functional outcomes after voice surgery.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.1-23
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• 1998

Work-related Low Back Pain(LBP) is one of tile most important Issues in the field of industrial safety and health. Particularly, manual lifting is known as a major cause of work-related LBP and impairment. Total number of 163 manual lifting tasks in motor assembly processes were investigated. The 1981 and the 1994 equations developed by National Institute for Occupational Safety and Health(NIOSH) were applied to evaluate potential hazards of lifting-related LBP. Comparisons between the 19R I and 1994 NIOSH criteria were made. The relationships between the NIOSH criteria and lifting-related LBP were also analyzed. The results of this study are as follows: 1. The values of Action Limit(AL) by the NIOSH 1981 lifting equation. Recommended Weight Limit(RWL) by the 1994 equation and the weight of the load handled at each manual lifting task were shown log-normal distributions. 2. LI'(the weight of tile load/AL) and LI(the weight of the load/RWL) were calculated estimate the physical stress imposed by each individual lifting task. As a result. 76.7% of the total LI' value exceeded 1 and 12.9% exceeded 3, and 84.7% of the total LI values exceeded 1 and 20.9% exceeded 3. 3. Bus 2 Department showed the highest rate of LI'>1 and LI>1 and Bus 1 Department showed the highest rate of LI'>3 and LI>3 4. In general, the RWLs by the 1994 equation were found lower than the ALs by the 1981 equation. It is assumed to he resulted from the fact that the 1994 equation includes methods evaluating asymmetrical lifting tasks and lifts of objects with less then optimal hand-container couplings, and also covers a larger range of work durations and lifting frequencies than the 1981 equation. 5. Significant correlations were found between LI' and incidence of LBP (R=0.734, p<0.05). LI and incidence of LBP(R=0.671. p<0.10) and load-weights and incidence of LBP(R=0.797, p<0.05). 6. Control measures are required to achieve the value of LI less than 1 for some tasks having high LI values. Engineering control is highly recommended for some tasks having the value of LI above 3.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.94-101
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• 1977

Noise pollution, both in the environment and in the workplace, has been recognized as a major health hazard -one that can impair not only a person's hearing but also his physical and mental well-being. As industrialization progresses, the prevalence rate of occupational diseases is increasing, especially hearing loss, which has the highest prevalence rate among the occupational diseases. The major cause of noise is the construction of various large industries without any regulation of noise sources. Therefor, we must establish an enactment to control mechanical noise sources. as soon as possible. For the purpose of controlling the noise source, we must have exact data about such things as the sound level, the frequency of the peak sound and the revolutions per minute (r.p.m.) of the machine (a measure of the power of its motor). This study was undertaken in order to define the noise characteristics, the power of the machine's motor, the change of the sound level and the peak sound as the r.p.m. increases, and the permissible exposure time. The sample size of this study was 74 machines at 11 plants in 6 industries. The results are as follows; 1. The breakdown of the types of mechanical noise noted was : 63.6% continuous normal sound, 26.9% intermittent sound, 4.7% continuous repeating sound and 4.6% impulsive sound. 2. With respect to the type of industry, the overall sound level was the highest in the mechanical industry, with $103.8{\pm}2.8dB(A)$, and lowest in the textile industry, with $89.2{\pm}1.43dB(A)$. 3. With respect to the type of machine, the highest sound level was 124 dB(A) caused by Gauzing(II), in the mechanical industry, and the lowest was 76 dB(A) caused by Attachment (Jup Chack) (I) in the timber industry. 4. The shortest permissible exposure time to Gauzing(II) in the mechanical industry was less than 15 minutes. 5. Among 74 machines, 68.2% of the peak sound was situated in the high frequency range (52.7% at 2 KHz, 4.1% at 4 KHz and 1.4% at 8 KHz). 41.8% of the peak sound was in the middle frequency range (4.1% at 250Hz, 14.8% at 500Hz and 22.9% at 1KHz). 6. If one machine had two motors or more, the peak sound was shifted to the low frequency range. 7. As the r.p.m. increased, the overall and peak sound levels were increased without any change of the frequency of the peak sound. 8. Whenever the machines had the same kind and the same r.p.m., the overall and peak sounds were changed by the physicochemical characteristics of the raw materials and the management.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.348-357
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• 2008

The classification of the effect of ionospheric disturbances on the radio occultation signal amplitude has been introduced based on an analysis of more than 2000 seances of radio occultation measurements per formed with the help of the CHAMP German satellite. The dependence of the histograms of variations in the radio occultation signal amplitude on the IMF variation index has been revealed. It has been indicated that it is possible to introduce the radio occultation index characterizing the relation between ionospheric disturbances and solar activity. An amplitude radio occultation (RO) method is proposed to study connection between the ionospheric and solar activity on a global scale. Sporadic amplitude scintillation observed in RO experiments contain important information concerning the seasonal, geographical, and temporal distributions of the ionospheric disturbances and depend on solar activity. The probability of strong RO amplitude variations (RO $S_4$ index greater than 0.2) in the CHAMP RO signals diminishes sharply with the weakening of solar activity from 2001 to 2008. The general number of RO events with strong amplitude variations can be used as an indicator of the ionospheric activity. We found that during 2001-2008 the daily globally averaged RO $S_{4a}$ index depends essentially on solar activity. The maximum occurred in January 2002, minimum has been observed in summer 2008. Different temporal behavoir of $S_{4a}$ index has been detected for polar (with latitude greater than $60^{\circ}$) and low latitude (moderate and equatorial) regions. For polar regions $S_{4a}$ index is slowly decreasing with solar activity. In the low latitude areas $S_{4a}$ index is sharply oscillating, depending on the solar ultraviolet emission variations. The different geographical behavoir of $S_{4a}$ index indicates different origin of ionospheric plasma disturbances in polar and low latitude areas. Origin of the plasma disturbances in the polar areas may be connected with influence of solar wind, the ultraviolet emission of the Sun may be the main cause of the ionospheric irregularities in the low latitude zone. Therefore, the $S_{4a}$ index of RO signal is important radio physical indicator of solar activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.2
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• pp.68-74
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• 2005

The electrical arc furnace (EAF) classified as a special waste contains many flux components producing melts during a sintering process, so it decreases the sintering temperature and improves the mechanical properties of specimens. Increasing dust content in a clay-dust system brick, however, may cause the fraction defective higher due to the excessive liquid produced. To control the liquid behavior produced during sintering process for the clay-dust system specimens, the $Al_2O_3$ was added and the physical properties were analyzed. The microstructure for the clay-dust system body sintered with $Al_2O_3$ became homogeneous and the overall size of pores decreased. Adding $Al_2O_3$ to clay-dust system body increased the mechanical properties and the temperature of maximum strength increased as much as $50^{\circ}C$, and the apparent density increased and the absorption decreased. The mullite ($3Al_2O_3{\cdot}2SiO_2$) was produced during sintering process by reaction of $Al_2O_3$ and $SiO_2$ which could participate to liquid-producing-process and the viscosity of melts increased which was proved by measuring a critical viscosity temperature (Tcv) therefore, the refractoriness of specimens were improved to lower the fraction defective.

• Journal of forensic and investigative science
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• v.3 no.1
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• pp.60-73
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• 2008

The purpose of Emergency Medical System(EMS) is what a patient returns to society with recovering mental tone in the shortest time as giving prompt and proper medical treatment to patient in emergency situation, and the Correctional Administration(CA) is purposed for the convict to return and settle down to society after release from prison in success as executing schooling, enlightenment activity, vocational training to convict who was quarantined from the society for the term of imprisonment. The EMS and CA will coincide each other which is reverting people to society in safety. This study aims to suggest the developmental program of EMS in correctional facilities through the cause of emergency situation, system, human resources, establishment, medical equipments, state of budget and the point issue for safety of victim who has many chances that is exposed to physical damage and disease because of particularity of lower culture in correctional facilities and the staff who works there. First, in the view of the correctional facility security system, a proper number of the emergency rescuers should be employed. Second, the effective transportation system along with some emergency medical equipment needs to be established. Third, the correctional officers and the prisoners should be learned the first-aid training which is realistic, practical and systematic. Fourth, the cooperative system should be established such as 1339 emergency medical information center in society. Fifth, the Ministry of Health and Welfare must increase EMS budget for correctional facilities.

• Journal of Environmental Science International
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• v.18 no.4
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• pp.463-471
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• 2009

A study on vegetation in the Mangyeong River and Dongjin River basins and the surrounding regions of the Saemangeum Reclaimed Land was conducted in a series of efforts to determine the expected ecological changes in the salt marshes, to restore their vegetation, to explore the restoring force of halophyte, to examine the community mechanism and, ultimately, to rehabilitate marshy land vegetation along the lakeside, coastal dune and salt marshes of the Saemangeum Project Area. The findings of the study may be summed up as follows: Five species such as Suaeda japonica, Salicornia herbacea, Atriplex gmelini, Aster tripolium and Suaeda asparagoides that are mostly distributed in the estuary of the Saemangeum Reclaimed Land were analyzed to examine the mechanism of halophyte to maintain their community. To find out the strategies of plants for survival and the cause of forming community structure, a research was made as for appearance ratio of biomass, root lengths and germination. With regard to biomasses of halophyte, the biomass of Suaeda japonica increases rapidly, while Salicornia herbacea adopts a strategy of unstable growth pattern by which the biomass increases slowly in parallel with its slow speed of growth since initial appearance of young sapling. In contrast, Suaeda asparagoides, Atriplex gmelini and Aster tripolium choose to adapt themselves to environment promptly by being transformed into life form of annual or biennial plant, a pattern that is presumed to be favorable and stable for survival in the later stage of growth. In short, there is a sharp distinction among the 5 species: i.e. Suaeda japonica that begins to grow fast in the length of surface and underground section but slows down from the mid-stage on; Salicornia herbacea that grows slowly in the beginning step but starts to step up from the middle onward; Atriplex gmelini and Aster tripolium growing slowly in the initial stage but fast later on; and Suaeda asparagoides that turns from the constant growth in the beginning to rapid growth in the later period. The outcomes of the analysis into status of growth and influencing factors of Suaeda japonica in the sowing field that is most widely prevalent in the Saemangeum Reclaimed Land as a sort of ecological pioneer in the salt marshes showed that the average size of grass lands, density and number of individuals increase in the natural sowing field as well as in the plowing field regardless of their physical as well as physico-chemical features of the soil as the season progresses from June to October of a year.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.586-591
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• 2002

Bruxism can be generally regarded as a diurnal clenching or nocturnal teeth grinding or a combination of both. Clenching of the teeth is forceful closure of the opposing dentition in a static relationship of the mandible to the maxilla, whereas grinding of the dentition is forceful closure of the opposing dentition in a dynamic maxillo-mandibular relationship as the mandibular arch moves through various excursive positions. The causes of bruxism are not yet discovered clearly, but most consistently mentioned cause is psychological stress. Bruxism can be also associated with sleep disorders, medication, and disturbances of the central nervous system. There is no permanent treatment method of bruxism, so the objectives for management of bruxism are reduction of psychological stress and treatment of signs and symptoms of bruxism by occlusal adjustment, occlusal splint, systemic medication and physical therapy. These cases report present three cases of children with bruxism. The bruxism was reduced in these patients wearing occlusal splint.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.4
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• pp.412-417
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• 2012

Mucopolysaccharidosis (MPS) is a disorder which is caused by the defect of the lysosomal enzyme that is essentially needed for resolution of glycosaminoglycans (GAGs). Metabolite of GAGs will accumulate in the lysosome of cells and will result in the dysfunction of cells, tissues, and organs. Eventually, patients will manifest both mental retardation and physical disorders. In worst cases, mucopolysaccharidosis can cause premature death. The current clinical types have been classified as MPS from type I to type IX according to the defect of certain enzyme. The dental complications have been reported as delay of eruption, enamel hypoplasia, microdontia, malocclusion, condylar defects, gingival hyperplasia and dentigerous cystlike follicle. This clinical report presents the case of a boy with MPS type II, Hunter Syndrome which has various dental complications.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.306-313
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• 2013

Speech is complex psycho-physiological mutual process which includes many orofacial organs. Especially, teeth play an especially important role as an articulation organ in conjunction with the lips and tongue. When teeth are missing, the position of tongue and mandible is adjusted to produce correct sound. If a patient's adaptive function is inadequate for modification of malocclusion, prosthodontic and orthodontic interventions are necessary. Missing teeth of young patients should be reconstructed bacause it can cause malocclusion, decreased masticatory efficiency, articulation disorders, esthetic problem, and temporomandibular disorder. Valplast$^{(R)}$(Valplast International Corp, New York, USA) flexible denture is useful for rehabilitation due to its excellent physical properties, esthetics, and small volume. This case is regardingan intellecturally disabled patient with anarticulation disorder caused by missing lower incisors due to trauma. The patient showed improvement in articulation by using flexible partial denture. The purpose of this report is to figure out the influence of missing lower anterior teeth on articulation.