• Journal of Oral Medicine and Pain
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• 제41권2호
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• pp.80-84
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• 2016

Non-odontogenic toothaches are frequently present and can be challenge to the dental clinician. A 41-year-old male patient with sharp and spontaneous pain on the right maxillary posterior dentition, which developed as like localized toothache 3 months ago, was finally treated with endoscope assisted sinus surgery on right maxillary sinus. Although the initial clinical characteristics are similar to odontogenic toothache in this patient, previous several treatment with the affected teeth did not alleviate the pain. Sinusitis around the facial structure is one of the common causes to make referred pain to maximally teeth and the sinus toothache resembles the pulpal or the periodontal toothache. The clinician should be well aware of various causes of the non-odontogenic toothache and be able to differentiate them.

• Journal of Microbiology
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• 제43권spc1호
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• pp.118-131
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• 2005

Vibrio vulnificus is an opportunistic pathogen of humans that has the capability of causing rare, yet devastating disease. The bacteria are naturally present in estuarine environments and frequently contaminate seafoods. Within days of consuming uncooked, contaminated seafood, predisposed individuals can succumb to sepsis. Additionally, in otherwise healthy people, V. vulnificus causes wound infection that can require amputation or lead to sepsis. These diseases share the characteristics that the bacteria multiply extremely rapidly in host tissues and cause extensive damage. Despite the analysis of virulence for over 20 years using a combination of animal and cell culture models, surprisingly little is known about the mechanisms by which V. vulnificus causes disease. This is in part because of differences observed using animal models that involve infection with bacteria versus injection of toxins. However, the increasing use of genetic analysis coupled with detailed animal models is revealing new insight into the pathogenesis of V. vulnificus disease.

• 대한인간공학회지
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• 제26권2호
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• pp.137-147
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• 2007

Dentists are known to be highly exposed to the musculoskeletal disorders (MSD). The present study investigated the prevalence of MSD among Korean dentists and association between their MSD and physical workload. In addition, work-related causes of high physical workload were identified and needs of dentists were collected for improvement of dental instrument and environment. Four types of questionnaires including the Nordic questionnaire were used to investigate body troubles, physical workload, causes of physical workload, and improvement priority of dental components. A total of 104 dentists in Seoul were participated in the survey. Neck trouble (82%) was the most prevalent in the participated dentists and shoulder (68%) and low back trouble (56%) followed, while low back trouble was reported to be most common in previous western studies. The body troubles were related to the physical workload of the corresponding body parts, although they were not associated with personal characteristics. Most dentists selected 'to keep direct view inside patient's mouth' and 'no support of the hand with dental instruments' as causes of awkward and strenuous work postures. They wanted design improvement for some components in their operating room such as operating light and arrangement of workplace.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.938-940
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• 1998

In order to improve insulating character and ability of insulating system of power apparatus, the interfacial and complex structure is widely used. However, the interface or complex structure of insulation materials is reported as a weak point which causes breakdown. As the interface of insulation system degrades its electrical property and eventually causes a failure, the datailed phenomenon analysis is reported. The object of this paper is to evaluate dielectric property of PET film with the interface. The $tan{\delta}$ increased with the existence of semiconducting layer and showed prominent decrease as a function of temperature. Also, the $tan{\delta}$ showed prominent increase as a function of frequency. The dielectric properties of interfacial were affected by the interface characteristics.

• 에너지공학
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• 제27권1호
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• pp.59-64
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• 2018

In this paper, we investigated the alternative sources of limestone. Oyster shell waste originated from aquaculture that causes a major disposal landfill problem in coastal sectors in southeast Korea. Their inadequate disposal causes a significant environmental problems araised. Bio mineralization leads to the formation of oyster shells and consists $CaCO_3$ as a major phase with a small amount of organic matter. It is a good alternative material source instead of natural lime stone. The utilization of oyster shell waste for industrial applications instead of natural limestone is major advantage for conservation of natural limestone. The present work describes the limestone and oyster shells hydraulic activity and chemical composition and characteristics are most similar for utilization of oyster shell waste instead of natural limestone.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.165-172
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• 1999

Crane operation for transporting heavy loads causes swinging motion at the loads. This sway causes the suspension ropes to leave their grooves and leads to possibility of serious damages. Generally crane is operated by expert's knowledge. Therefore, a satisfactory control method to supress object sway during transport is indispensible. The dynamic behavior of the crane shows nonlinear characteristics. when the length of the rope is changed the crane is time varying system and the design of anti-sway controller is very difficult. In this paper, the nonlinear dynamic model for the industrial overhead crane is derived. and the feedback gain matrix based on the pole-placement method is proposed to supress the swing motion and control the position of the crane. The performance of the controller for the crane model is simulated on the personal computer.

• 대한후두음성언어의학회지
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• 제17권2호
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• pp.138-142
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• 2006

Objectives : Vocal cord paralysis(VCP) is a complex disorder which may result from numerous causes. We reviewed and analyzed the trend of clinical characteristics and causes of VCP in Korean patient. Method : A total 197 patients with VCP who visited St.Mary's hospital from March, 2000 to August, 2006 were reviewed retrospectively. They were analyzed according to sex, age, cause of VCP, position of paralyzed vocal fold, treatment methods. Results : The male and female ratio was 1.6 : 1. The unilateral paralyzed vocal fold was fixed at paramedian position in 84% of the cases. The left vocal fold was paralyzed about 2 1/2 times as much as the right vocal fold. Among the causes of VCP 30.9% of the cases were due to postoperative paralysis, and most of those were developed after lung, mediastinal surgery. laryngeal EMG was performed in 47 patients for determines the prognosis and treatment method. In the unilateral VCP, 90 patients were treated with injection laryngoplasty, 21 patients were performed thyroplasty type I. Conclusion : The causes of VCP include various diseases, so, detection of the primary disease is very important, because many fatal diseases are included among the primary diseases, and late detection can cause serious problems. VCP is not only a disease entity in itself, but can be seen as a sign of an underlying disease.

• 대한음성학회지:말소리
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• 제47호
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• pp.97-107
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• 2003

Speaker change detection is to detect automatically a point of time at which speaker was replaced. Since feature parameters used for speaker change detection depend not only on speaker characteristics but also on phonetic characteristics, spoken contents included in the feature parameters inevitably causes performance degradation of speaker change detection. In this paper, to alleviate this problem, a method to normalize phonetic variations in speech feature parameters is proposed for emphasizing changes due to speaker characteristics. Experimental results show that the proposed method improves the performance of speaker change detection.

• 대한가정학회지
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• 제41권10호
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• pp.199-209
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• 2003

The purpose of this study was to investigate the causes of bankruptcy in small apparel stores. Data were collected from 153 apparel retail store owners who experienced failure in small apparel stores in Busan. The results showed as follows; The internal factors that caused bankruptcy in small apparel stores were the problems related with employees, capital, investment, weak marketing strategies, inadequate management, and characteristics of store owners. The external factors were economic condition, unexpected incidents, and the condition of market. There were significant differences in the perception of factors which caused the store bankruptcy according to prior business experience before opening apparel stores, the level of education, and the period between store opening and closing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.606-608
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• 2005

As the overhead transmission lines are exposed to the outdoor weather, the causes of the transmission lines faults are from natural conditions, and among these faults, the outage rate due to lightning is more than 60%. The lightning causes the damage of power system equipments, the shut down of electricity and the electro-magnetic interference. Therefore, the pertinent insulation design is important, not only to decrease the damage of the facility itself but also to increase the reliability of electric power system. For these reasons, we have to obtain and accumulate the lightning current parameters for the basic lightning research. This paper describes the statistical distribution of lightning current parameters and the IKL map.