• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.33-39
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• 2019

The square timbers of larch having cross section of $90mm{\times}90mm$ were glued laterally to be formed $1,200mm{\times}2,400mm$ panels which were used as cores for CLT wall panels. Then, structural plywood panels having size of $1,200mm{\times}2,400mm$ were used as cross band covering the small square timber cores to manufacture CLT wall panels. The sound absorption rate of CLT wall panels and polyester board attached CLT wall panels were investigated. The mean sound absorption coefficients of the former and the latter in the frequency range of 100-6400 Hz were 0.21 and 0.74, respectively. The noise reduction coefficients (NRC) of those were 0.21 and 0.40, respectively. Also, the mean sound transmission loss of CLT wood panel in the frequency range of 50-1600 Hz was 45.12 dB and that value at the frequency of 500 Hz was 42.49 dB. It was suggested that the polyester board attached CLT wall panels could be used as housing wall because of its high sound absorption rate and high sound transmission loss.

• Journal of Acupuncture Research
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• v.30 no.5
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• pp.155-167
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• 2013

Objectives : This research was conducted to investigate the factors that affect the level of facial nerve damage. Methods : From October 2009 to September 2013, the total number of 581 patients of Bell's palsy and Ramsay-Hunt syndrome visited Facial Palsy Center in Kyung Hee University Hospital at Gangdong for Traditional Korean and Western combined medical treatment. Of these, 453 patients of peripheral facial nerve palsy were selected for the research. After reviewing the medical records that have details of age, gender, diagnosis(Bell's palsy and Ramsay-Hunt syndrome), onset, underlying diseases(DM, HTN), and HbAlc value, the analysis on the influence factors on the level of facial nerve damage was drew out. Results : The axonal loss rate of oris branch and nasal branch were significantly higher than the axonal loss rate of frontal branch and oculi branch. In addition, the frequency of becoming a major damaged branch was also high in the oris branch nasal branch. The factors by month, weather, smoking, and alcohol did not influence EMG axonal loss rate. Male rather than female and patient with Rasmay-Hut syndrome rather than Bell's palsy had a higher axonal loss rate in all branches. Of those, front of branch of male was remarkably higher than female. Patient with DM as P/H had high axonal loss rate in all branches. Patient with HTN as P/H had high axonal loss rate in all branches except for oris branches. Patients with DM and HTN group had significantly higher value from the average of axonal loss rate than patients who are only with HTN and without DM/HTN. DM alone group had significantly higher value than patients who are without DM/HTN. However, HTN alone was not significantly high. By analysing HbAlc of the patients who were hospitalised regardless DM, axonal loss rate was high in the order of DM group, preDM group, normal group. Nevertheless, only DM group showed higher axonal rate statistically than normal group. Considering DM and HbA1c value, the patients can be divided into 4 different groups of hkDM, lkDM, hfDM and nDM. By analysing those groups, the average damaged value of the groups with diagnosis followed by treatment(lkDM, hkDM) were higher than the average rate of hfDM and statistically higher than the rate of the nDM. Conclusions : The influential factors of increasing the level of EMG damage are male(only for the frontal branch), age above sixties, HTN, DM, and HbAlc value above 6.5. Besides, the negligible factors are month, season, diagnosis, alcohol, and smoking. Further research including clinical prognosis should be conducted.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.42.1-42.7
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• 2016

Background: The purpose of this retrospective study was to evaluate the clinical utility of an implant with a sandblasted, large-grit, acid-etched (SLA) surface and internal connection. Methods: Six patients who received dental implants in the Department of Oral and Maxillofacial Surgery, Chonnam National University Dental Hospital, were analyzed by factors influencing the success rate and marginal bone loss. Factors included patient's age, sex, implant installation site, whether bone graft was done, type of bone graft materials, approaching method if sinus lift was done, and the size of the fixture. In addition, the marginal bone loss was analyzed by using a radiograph. Results: All implants were successful, and the cumulative survival rate was 100 %. Average marginal bone loss of 6 months after the installation was 0.52 mm and 20 months after the functional loading was 1.06 mm. Total marginal bone resorption was 1.58 mm on average. There was no statistically significant difference in mesial and distal marginal bone loss. Conclusions: The short-term clinical success rate of the implant with an SLA surface and internal connection was satisfactory. Moreover, the marginal bone loss was also consistent with the implant success criteria.

• Journal of the Korean Geotechnical Society
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• v.26 no.5
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• pp.37-48
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• 2010

In this study, the seepage flow monitoring method by the hydraulic head loss rate was developed for the purpose of application to offshore construction site enclosed by cofferdams in which seepage force varies periodically. The amount of the hydraulic head loss rate newly defined in this graph was in a range between 0 and 1. The zero of the rate means the existence of flow with no seepage resistance. The 1 of the rate means no seepage flow through the ground. The closer to 1 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows is stable. The closer to 0 the coefficient of determinant in the hydraulic head loss graph is, the more the ground through which seepage water flows was unstable and the higher the possibilities of existence of empty space or of occurrence of piping on the seepage flow pass in the ground is. The hydraulic head loss graph makes it possible to monitor sensitively the situation of seepage flow state, and the graph helps to understand easily the seepage flow state at the specific section on the whole cofferdam.

• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.165-183
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• 2015

It is well known that, since the 15th century, the amount of soil loss in our country due to change in land use by human has increased more rapidly than ever before. However we cannot answer the question 'How long can the soil persist under the current rates of soil loss?', because it was difficult to quantify the soil production rate. With the advancement of accelerated mass spectrometry, the attempt to quantify rate of soil production and derive soil production function succeeded, and recently it was also applied into the Daegwanryeong Plateau. Here we introduce the principles for quantifying soil production and deriving soil production function using terrestrial cosmogenic nuclides, and then compare the soil production rates from the plateau with soil loss data after the late 20th century, and finally estimate how long the soil can persist. Averaged soil production rate since the Holocene derived from the plateau is revealed as ${\sim}0.05[mm\;yr^{-1}]$, and, however, the recent soil loss rate of intensively used farmlands at the same region is up to sixty times greater than the soil production rate. Thus, if current land use system is maintained, top soils on the cultivated lands over hillslopes especially in upland areas are expected to disappear within several decades at the earliest.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.521-529
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• 2002

A restraint coefficient for creep and dry shrinkage deformation of concrete in a composite section was derived to calculate the residual stress, and an equation for the loss rate of the pre-compression force was proposed. The derived restraint coefficient was computed by using the transformed section properties for the age-adjusted effective modulus of elasticity. The long-term behavior of complicate composite sections could be analyzed easily with the restraint coefficient. The articles of the current design code was examined for PSC and steel composite sections. The dry shrinkage strains of $150 ~ 200$\times$10^{-6}$ for the computations of the statically indeterminate force and the expansion joint could be under-estimated for less restrained sections such as the reinforced concrete. The dry shrinkage strain of $180$\times$10^{-6}$ for the computation of residual stress in the steel composite section was unreasonably less value. The loss rate of 16.3% of the design code for the PSC composite section in this study was conservative for the long-term deformation of the ACI 205 but could not be used safely for that of the Eurocode 2. For pre-compressed concrete slab in the steel composite section, the loss rate of prestressed force with low strength reinforcement was much larger than that with high strength tendon. The loss rate of concrete pre-compression increased, while that of pre-tension decreased due to the restraint of the steel girder.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.218-223
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• 2008

In this paper, we implement several methods to improve an audio collaboration system over IP networks, and then evaluate the performance of the implemented methods. In general, speech and audio quality degrades depending on the characteristics of IP networks such as jitter and packet loss. In order to reduce this quality degradation, we propose a lower bit rate audio delivery scheme using the MPEG-2 AAC (Advanced Audio Coding) audio codec in a viewpoint that a packet loss rate could be reduced by a smaller packet size. In addition, iLBC (Internet Low-Bitrate Codec) and the G.711 packet loss concealment algorithm defined by IEFT and ITU-T, respectively, are applied to a audio collaboration system. RAT (Robust-Audio Tool)[7] is used as a baseline platform for the implementation of the proposed methods. It is shown from the implementation that the implemented MPEG-2 AAC audio codec with a bitrate of 256 kbit/s performs as similar as the uncompressed audio quality with a bitrate of 512 kbit/s, and that iLBC and the G.711 packet loss concealment algorithm can improve speech quality when a packet loss rate is 2~10%.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.495-509
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• 2015

We study a classification problem of significant differences in the proportion of two groups known as the unbalanced classification problem. It is usually more difficult to classify classes accurately in unbalanced data than balanced data. Most observations are likely to be classified to the bigger group if we apply classification methods to the unbalanced data because it can minimize the misclassification loss. However, this smaller group is misclassified as the larger group problem that can cause a bigger loss in most real applications. We compare several classification methods for the unbalanced data using sampling techniques (up and down sampling). We also check the total loss of different classification methods when the asymmetric loss is applied to simulated and real data. We use the misclassification rate, G-mean, ROC and AUC (area under the curve) for the performance comparison.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.30-35
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• 1998

Background: Idiopathic sudden sensorineural hearing loss(ISSHL) has been generally defined as an abrupt loss of auditory acuity without precipitating factors. Since ISSHL was first described as a disease entity, numerous reports assessing a variety of treatment regimens have been published. But its etiology, pathogenesis, treatment, and prognosis are controversial at the present time. Stellate ganglion block(SGB) has been used for the treatment of ISSHL by vasodilatation and increased blood flow to the inner ear. Methods: We reviewed the records of 152 patients to investigate the efficacy of SGB for ISSHL. The control group was managed with medications such as hypaque, heparin, steroid, nicotinic acid, and vitamins. The SGB group was managed with SGB and the same medications. SGB was performed with 8 ml of 1.0% mepivacaine. The efficacy of treatment was evaluated by pure-tone average following therapy. The recovery of hearing was defined as Siegel's criteria I, II, or III. Results: The recovery rate of the SGB group was higher than that of the control group(61.5 vs. 42.9%, p<0.05). The recovery rate was higher in patients who were treated early, within 7 days from the onset of symptoms, especially in the SGB group(79.7%). And in the case that initial hearing loss was severe (>70dB), the SGB group had a higher recovery rate(64.2%) than the control group(42.5%). Conclusions: SGB is thought to be a useful therapy for ISSHL, especially in the patients who were treated soon after onset or whose initial hearing loss was severe.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1218-1223
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• 2003

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.