• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.1
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• pp.33-42
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• 2012

Background and Objectives : Dysarthria refers to speech disorder that causes difficulties in speech communication due to paralysis, muscle weakening, and incoordination of speech muscle mechanism caused by damaged central or peripheral nerve system. Pitch, strength and speed are influenced by dysarthria during detonation due to difficulties in muscle control. As evaluation items, alternate motion rate and diadochokinesis have been commonly used, and articulation is also an important evaluation items. The purpose of this study is to find acoustic characteristics on sound production of dysarthria patients. Materials and Methods : Research subjects have been selected as 20 dysarthria patients and 20 subjects for control group, and voice sample was composed of bilabial, alveolar sound, and velar sound in diadochokinetic rate, while consonant articulation test was composed of bilabial plosive, alveolar plosive, velar plosive. Analysis items were composed of 1) speaking rate, energy, articulation time of diadochokinesis, 2) voice onset time (VOT), total duration (TD), vowel duration (VD), hold of plosives. Results and Conclusions : The number of diadochokinetic rate of dysarthria was smaller than control group. Both control group and dysarthria group was highly presented in the order of /t/>/p/>/k/. Minimum energy range per cycle during diadochokinetic rate of dysarthria group was smaller than control group, and presented statistical significance in /p/, /k/, /ptk/. Maximum energy range was larger than control group, and presented statistical significance in /t/, /ptk/. Articulation time, gap, total articulation time during diadochokinetic rate of dysarthria group was longer than control group and presented statistical significance. The articulation time was presented in both control group and dysarthria group in the order of /k/>/t/>/p/, while Gap was presented in the order of /p/>/t/>/k/ for control group and /p/>/k/>/t/ for dysarthria group. VOT, TD, VD regarding plosives of dysarthria group were longer than control group. Hold showed large deviation compared to control group that had appeared due to declined larynx and articulation organ motility.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.138-143
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• 1990

In mature stand of Japanese larch (Larix leptolepis(S. et Z.) Gordon) planted in 1925, heartrot damage was investigated by felling some infected trees with fruit bodies of two butt-rot fungi, Phaeolus schweinitzii and Sparassis crispa. Percentage of heartrot area on basal area of decay trees was 19.2-74.4, and the height reached by the decay was 1.2-5.5m. Percentage of decay volume was in the range of 2.2-13.4%, but the loss wood to the height reached by the decay amounted to 27.2% (range 13.1-37.1%) of whole volume, Decay damage caused by S. crispa was much greater than that caused by P. schweinitzii. Compressive strength ($52-77kg/cm^2$) and specific gravity (0.40-0.47) of rot wood was reduced to 77% and 39% respectively in maximum as compared to sound wood of healthy tree, and those of sound-looking wood close by heartrot to 42% and 26%. The current annual growth of trees with decay was fallen behind that of sound tree from eight to fourteen years after planting in D. B. H. and from twelve to twenty-one years after in volume.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.1-8
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• 2024

For measuring the performance of passive sonars, we usually consider the maximum Detection Range (DR) under the environment and system parameters in operation. In shallow water, where sound waves inevitably interacts with sea surface or bottom, detection generally maintains up to the maximum range. In deep water, however, sound waves may not interact with sea surface or/and bottom, and thus there may exist shadow zones where sound waves can hardly reach. In this situation, DR alone may not completely define the performance of each sonar. For complete description of sonar performance, we employ the concept 'Robustness Of Detection (ROD)'. In the coastal region of the East Sea, the spatial variations of water masses have close relations with DR and ROD, where the two parameters show reverse spatial variations in general. The spatial and temporal analysis of the temperature by employing the Empirical Orthogonal Function (EOF) shows that the 1-st mode represents typical pattern of seasonal variation and the 2-nd mode represents strength variations of mixed layers and currents. The two modes are estimated to explain about 92 % of the variations. Assuming two types of targets located at the depths of 5 m (shallow) and 100 m (deep), the passive sonar performance (DR) gives high negative correlations (about -0.9) with the first two modes. Most of temporal variations of temperature occur from the surface up to 200 m in the water column so that when we assume a target at 100 m, we can expect detection performance of little seasonal variations with passive sonars below 100 m.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.72-81
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• 2017

The aim of this study was to evaluate the effectiveness of artificial saliva contamination and decontamination procedures at different stages of a bonding procedure on the microtensile bond strength (MTBS) of two one-step self-etch adhesives and a two-step total-etch adhesive to dentin of primary teeth. Forty-two extracted sound primary molars were randomly divided into three groups depending on three adhesives, Scotchbond Universal Adhesive (SBU), All-Bond Universal (ABU) and Prime & Bond NT (PNT). For each adhesive, the teeth were allocated into seven groups. Except for control group, group 1, the groups were contaminated with artificial saliva at three different stages: the groups 2 and 3 - before adhesive application; the groups 4 and 5 - before adhesive polymerization; the groups 6 and 7 - after adhesive polymerization. Decontaminating procedures were rinsing, air-drying (group 2, 4, 6) and air-drying (group 3, 5, 7). The specimens were restored with composite resin (Filtek, Z350) and microtensile bond strength was measured. The data was analyzed with one-way ANOVA and Tukey HSD test (p < 0.05). In the control group, using PNT resulted in significantly higher bond strength than when ABU and SBU were used (p < 0.001). For three adhesives, the groups 2, 4 and 6 had greater bond strength than the groups 3, 5 and 7. Also, when the artificial saliva was contaminated before adhesive polymerization (group 4, 5), it showed a significantly lower bond strength. Generally the two-step total-etch adhesive generated a higher bond strength than the one-step self-etch adhesive. Artificial saliva contamination before adhesive polymerization led to a drastic decrease in bond strength, and rinsing with water followed by air-drying could not recover the bond strength.

• Journal of Powder Materials
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• v.20 no.2
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• pp.114-119
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• 2013

In the DBC (direct bonding of copper) process the oxygen partial pressure surrounding the AlN/Cu bonding pairs has been controlled by Ar gas mixed with oxygen. However, the direct bonding of Cu with sound interface and good adhesion strength is complicated process due to the difficulty in the exact control of oxygen partial pressure by using Ar gas. In this study, we have utilized the in-situ equilibrium established during the reaction of $2CuO{\rightarrow}Cu_2O$ + 1/2 $O_2$ by placing powder bed of CuO or $Cu_2O$ around the Cu/AlN bonding pair at $1065{\sim}1085^{\circ}C$. The adhesion strength was relatively better in case of using CuO powder than when $Cu_2O$ powder was used. Microstructural analysis by optical microscopy and XRD revealed that the interface of bonding pair was composed of $Cu_2O$, Cu and small amount of CuO phase. Thus, it is explained that the good adhesion between Cu and AlN is attributed to the wetting of eutectic liquid formed by reaction of Cu and $Cu_2O$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.157-164
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• 2009

Due to change of various marine environments according to seawater temperature rising, Japanese common squid(Todarodes pacificus), which was distributed in East Sea, was recently caught in Yellow Sea during a summer season from 2006. The fishery resources density research was carried out in Korea-China Provisional Water Zone using trawl fishing gear and acoustics in National Fisheries Research & Development Institute in Korea. This paper showed the analysis on the acoustical backscattering strength by two frequencies(38kHz, 120kHz) for Japanese common squid by acoustical scattering theoretical model based on size distribution for survey period, and estimate the density distribution for squid s integrated layer which was extracted from any scatterers distributed in water column using two frequency difference method which has been used to distinguish fish shoals or specific target scatterers from sound scattering layer which is composed of various zooplankton. Furthermore, the entire range of their density estimation was suggested using by Monte Carlo simulation under considering each uncertainty such as size distributions or swimming angle and so on in survey area.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.404-410
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• 2016

PURPOSE. Considering the importance of retention in the success and long-term clinical service of fixed partial dentures (FPDs) as well as the existing controversy regarding the effect of GLUMA desensitizer on the retention of full metal crowns cemented with RelyX U200 self-adhesive cement, this study aimed to assess the effect of GLUMA desensitizer on the retention of full metal crowns cemented using RelyX U200. MATERIALS AND METHODS. In this experimental study, 20 sound human premolars were prepared; a 0.5 mm chamfer finish line was prepared above the cementoenamel junction. The teeth were randomly assigned to two groups: a desensitizer group (n = 10, treated with GLUMA desensitizer) and a control (n = 10, no surface treatment). Full metal crowns were fabricated of base metal alloy and had a ring. All crowns were cemented with RelyX U200 and subjected to retention test by using a universal testing machine. The data were analyzed using SPSS version 20 and independent t-test. RESULTS. The mean tensile bond strength was significantly higher in the GLUMA desensitizer group ($230.63{\pm}63.8N$) compared to the control group ($164.45{\pm}39.3N$) ($P{\leq}.012$). CONCLUSION. GLUMA desensitizer increases the tensile bond strength of RelyX U200 self-adhesive cement to dentin.

• Advances in concrete construction
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• v.9 no.2
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• pp.217-225
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• 2020

The recovery of waste proves a solution with two impacts: the environmental impact by the reduction of pollution and the gain of the occupied space by this waste, and the economic impact by the use of these lasts in the building and in the area of public works. The present research consists in recovering a waste marble (thrown powder exposed to the different meteorological phenomena) generated by the quarry marble of Fil-fila, located at the east side of Skikda in the north-east of Algeria, and add it, as sand in the composition of sand concrete. To carry out this research, we analyzed the evolution brought by the substitution of ordinary sand by marble waste sand, with 25%, 50%, 75% and 100% on the properties in the fresh state (density, workability and air content) and in the cured state (compressive strength, tensile strength, surface hardness and sound velocity). For durability we tested water absorption by immersion and chloride penetration. The results obtained are compared with control samples of 0% of substitution rate. In order to have a good filling of the voids in the granular skeleton; we added a quantity of limestone recycled fines from the quarries and for a good workability a super-plasticizing additive. The results showed that the partial substitution modified both the fresh and the hardened characteristics of the tested concretes, the durability parameters also improved.

• Journal of Korean Society of Steel Construction
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• v.23 no.1
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• pp.1-12
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• 2011

Due to the concept of "full-strength capacity connection," the pushover analysis method became an issue in designing steel connections. It is difficult to apply practically, however, because engineers are unfamiliar with such method. Moreover, there have been insufficient representative studies on them because most of the past pertinent studies were performed based on high-rise and/or virtual structures. As such, for this study, an actual(now in process) steel structure, a medium-low-rise industrial building, was selected. To perform pushover analysis, it was suggested that lateral load patterns be used in a simple and clear manner for three- and two-dimensional analysis models. A new hinge property was also suggested to prevent erroneous connection design results that can occur in the design process. The suggested load patterns showed almost the same results regardless of the model that was used, from which the obtained load patterns were different. This result implies the validity of the suggested load patterns. As for the suggested hinge property, the structural analysis yielded sound and reasonable results, which confirmed the validity of the proposed hinge property.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1059-1065
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• 2010

Recently, analog broadcasting are being converted into digital radio broadcasts, Among the various ways that HD Radio is a candidate for the U.S. approach, Digital Radio will transmit a digital signal to existing analog FM/AM. It provides clear sound quality, traffic information, weather information and various value-added services. In addition, the converted digital radio will be able to meet demand to growing demand for analog FM. In this paper, Digital FM Radio system in the same frequency band using electric field strength of the received digital radio broadcasting interference effects were analyzed. And Digital FM Radio Receiver interference effects were analyzed by interference signal power and signal power. Results were confirmed by applying equation at minimum field strength and SNR.