• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.2
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• pp.182-188
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• 1999

Tinnitus is a symptom frequently encountered in the E.N.T. clinic and variously described as buzzing, ringing and thumping sound, etc., but the cause, pathogenesis, specific treatment remains to be established through close investigation. In fact, it is not easy to evaluate the treatment efficiency of tinnitus reasonably. However, in this study. we clinically investigated 47 patients who visited E.N.T. department of Kyung Won University Hospital from May. 1996 to May. 1999 and belonged to specific bianzheng(辨證) types of tinnitus classified by bianzheng(辨證), a kind of diagnostic method in order to estimate efficiency of the treatment and give aids to establishing more effective and recognizable treatment method. The result is as follows: 1) In bianzheng(辨證) types of tinnitus, Piweixuruo(脾胃虛弱) was most frequently found, in descending order, Shenjingkuisun(腎精虧損), Ganhuoshangra(肝火上擾), Tanhuoyongjie(痰火壅結). 2) In the treatment efficiency, the type of Piweixuruo(脾胃虛弱) showed the highest, in descending order, Ganhuoshangrao(肝火上擾), Tanhuoyongjie(痰火壅結) and Shenjingkuisun(腎精虧損). 3) The treatment efficiency is shown higher in patients with tinnitus included in other sysmptoms than those with a simple symptom of tinnitus. especially in case of tinnitus accompanied by vertigo, we could get much higher treatment efficiency more than we had expected.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1356-1361
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• 2018

Replacing conventional Si diodes with SiC diodes in Si insulated gate bipolar transistor (IGBT) modules is advantageous as it can reduce power losses significantly. Also, the fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present conventional Si diodes cannot do. In this work, the electrical test results for Si-IGBT/4HSiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. These substrates are built for two voltage ratings, 1.7 kV and 3.3 kV. Comparisons of the 1.7 kV and the 3.3 kV Si-IGBT/Si-diode substrates (Si substrates) at room temperature ($20^{\circ}C$, RT) and high temperature ($H125^{\circ}C$, HT) have shown that the switching losses in hybrid SiC substrates are miniscule as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the current waveforms. Also, the effect of design variations on the electrical performance of 1.7 kV, 50 A diodes is reported here. These variations are made in the active and termination regions of the device.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.161-165
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• 2023

This paper designed a voltage feedback driving circuit to compensate for the characteristic deviation of the Active Matrix Organic Light Emitting Diode driving Thin Film Transistor. This paper describes a stable and fast circuit by applying charge sharing and polar stabilization methods. A 12-inch Organic Light Emitting Diode with a Double Wide Ultra eXtended Graphics Array resolution creates a screen distortion problem for line parasitism, and charge sharing and polar stabilization structures were applied to solve the problem. By applying Charge Sharing, all data lines are shorted at the same time and quickly positioned as the average voltage to advance the compensated change time of the gate voltage in the next operation period. A buffer circuit and a current pass circuit were added to lower the Amplifier resistance connected to the line as a polar stabilization method. The advantage of suppressing the Ringing of the driving Thin Film Transistor can be obtained by increasing the stability. As a result, a circuit was designed to supply a stable current to the Organic Light Emitting Diode even if the characteristic deviation of the driving Thin Film Transistor occurs.

• Journal of Oral Medicine and Pain
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• v.18 no.2
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• pp.29-41
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• 1993

A prevalence study was carried out on 847 CMD patients who had visited the Department of Oral Medicine in Pusan National University from 1990 to 1993. To obtain the same type of information, all subjects were interviewed and examined clinically using a standardized examination form, The ratio of women to men was about 3:1 and all subjects were divided into acute and chronic groups on the basis of 6 months of duration. Diagnostic groups consisted of muscle disorder, joint disorder and muscle-joint disorder. As related to gender, duration and diagnosis subjective and objective symptoms in CMD were studied. The obtained results were as follows : 1. Muscle-joint disorder had the highest percent, followed by muscle disorder and joint disorder. 2. The most common reasons for CMD treatment were pain, joint noise and limited opening, while headache and neckache were relatively often reported as associated symptoms and dizziness, ringing in the ears also reported as secondary CNS excitatory effects. 3. Pain was more ofter seen in women, acute group and muscle-related disorder groups (p<0.05, p<0.01). Noise was significantly frequent in chronic group and joint-related groups (p<0.01). 4. Analysis of contributing factors presented that macrotrauma was found frequently in men (p<0.05), and that muscle-related groups were more related to stress than joint disorder grop (p<0.05). 5. Hard end feel was seen significantly often in joint-related disorder group (p<0.05). On the other hand, soft end feel was frequent in muscle disorder. 6. Reciprocal clicks and crepitation increased with chronicity. Subjects with joint-related disorder groups significantly often reported all kinds of noises (p<0.01). 7. Tender muscles and joints were more often reported in women and chronic group. Whereas muscle-related disorder groups revealed significantly more tender muscles (p<0.01). joint-related disorder groups presented significantly more tender joints (p<0.01).

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.395-400
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• 2002

This paper outlines the case of a 56 year-old man undertaking treatment by means of luxation and forced eruption of an ankylosed canine. At the time of diagnosis, the ankylosis of the tooth was not suspected, because there were not signs of intrusive luxation nor horizontal diaplacement. Only after the application of a vertical elastic force failed to erupt the maxillary left canine, was the ankylosis of that tooth suspected. At the time of reevaluation, the maxillary left canine hads no physiologic tooth mobility and emitted a sharp, ringing sound upon percussion. Hence, the maxillary left canine was considered ankylosed. The treatment course then changed to the extrusion of the canine through the surgical luxation of the tooth and the prompt application of vertical extrusive forces. The above outcome was successful for the patient not only in the orthodontic aspect, but also in terms of the periodontal considerations

• Journal of Ocean Engineering and Technology
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• v.29 no.1
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• pp.34-44
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• 2015

A hydraulic tensile test machine (HSTM) is one of the devices used to obtain the flow stress of a material during high-speed elongation. This paper first describes some features of a newly built HSTM. The improvement histories of the upper and lower jigs, which are the most vital parts of the HSTM, are also presented. We have frequently witnessed test failures with 1st generation jigs and specimens due to slip between the jig and specimen. 2nd generation jigs provide more stable test results, but the use of a longer upper jig induces excessive vibration and consequently makes it difficult to attach an environment chamber. 3rd generation jigs have some advances in terms of the symmetric fastening between the upper jig and specimen, as well as an exemption from direct contact between the lower jig and specimen. The performance of an environment chamber is verified by high and low temperature tests. A high-speed displacement measurement system is introduced based on a high-speed camera and motion-tracking software with aid of a surface grid device for the specimen.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.143-150
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• 2018

This work conducted the experimental analysis on ultrasonic acoustic matching in order to measure the accuracy of gaseous fuel level values. The experimental devices were used as 12V-DC supply, control T1 board, oscilloscope (DS01072B), ultrasonic probe and pattern table. The research models were designed by ceramic assay which can determine the transmitting and receiving energies. The result of the ringing area could verify the increased characteristics in the order of D (0.180m) < E (0.184m) < B (0.204m) < A (0.234m) < F (0.244m) < C (0.247m) models based on initial 2.9V of the maximum peak voltage. From the experimental results, the model designed by Ø21*3+2t of the matching layer was notable in that the most outstanding directivity energy could be created.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.585-593
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• 1998

In Fourier magnetic resonance imaging (MRI), the number of phase encoded signals is often reduced to minimize the duration of the studies and maintain adequate signal-to-noise ratio. However, this results in the well-known truncation artifact, whose effect manifests itself as blurring and ringing in the image domain. In this paper, we propose a new regularization method in the context of a Bayesian framework to reduce truncation artifact. Since the truncation artifact appears in t도 phase direction only, the use of conventional piecewise-smoothness constraints with symmetric neighbors may result in the loss of small details and soft edge structures in the read direction. Here, we propose more elaborate forms of constraints than the conventional piecewise-smoothness constraints, which can capture actual spatial information about the MR images. Our experimental results indicate that the proposed method not only reduces the truncation artifact, but also improves tissue regularity and boundary definition without oversmoothing soft edge regions.

• Ocean Systems Engineering
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• v.7 no.3
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• pp.179-193
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• 2017

Dynamic response analysis of offshore triceratops with stiffened buoyant legs under impact and non-impact waves is presented. Triceratops is relatively new-generation complaint platform being explored in the recent past for its suitability in ultra-deep waters. Buoyant legs support the deck through ball joints, which partially isolate the deck by not transferring rotation from legs to the deck. Buoyant legs are interconnected using equally spaced stiffeners, inducing more integral action in dispersing the encountered wave loads. Two typical nonlinear waves under very high sea state are used to simulate impact and non-impact waves. Parameters of JONSWAP spectrum are chosen to produce waves with high vertical and horizontal asymmetries. Impact waves are simulated by steep, front asymmetric waves while non-impact waves are simulated using Stokes nonlinear irregular waves. Based on the numerical analyses presented, it is seen that the platform experiences both steady state (springing) and transient response (ringing) of high amplitudes. Response of the deck shows significant reduction in rotational degrees-of-freedom due to isolation offered by ball joints. Weak-asymmetric waves, resulting in non-impact waves cause steady state response. Beat phenomenon is noticed in almost all degrees-of-freedom but values in sway, roll and yaw are considerably low as angle of incidence is zero degrees. Impact waves cause response in higher frequencies; bursting nature of pitch response is a clear manifestation of the effect of impact waves on buoyant legs. Non-impact waves cause response similar to that of a beating phenomenon in all active degrees-of-freedom, which otherwise would not be present under normal loading. Power spectral density plots show energy content of response for a wide bandwidth of frequencies, indicating an alarming behaviour apart from being highly nonlinear. Heave, being one of the stiff degrees-of-freedom is triggered under non-impact waves, which resulted in tether tension variation under non-impact waves as well. Reduced deck response aids functional requirements of triceratops even under impact and non-impact waves. Stiffened group of buoyant legs enable a monolithic behaviour, enhancing stiffness in vertical plane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3631-3637
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• 2013

Gangway bellows in this study is the double wrinkled neoprene rubber component to accept various deviations between the carriage end parts of the articulated type high speed railway vehicle(HSRV). The fatigue failure of the bellows has a harmful effect on the riding comfort for the passengers with the increase of noise and ringing in the ears due to air-tightness failure during pass through a long tunnel. In this study, to assure the safety of gangway bellows of the HSRV, non-linear analysis of the gangway bellows considering triaxial angular displacement(rolling /yawing/pitching) between the carriage end parts are performed. The non-linear properties of the rubber are determined by uniaxial tension and equi-biaxial tension test. Moreover, from the results of non-linear analysis, the effects of the angular displacements and frictional coefficients are evaluated.