• The Journal of the Acoustical Society of Korea
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• v.25 no.4
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• pp.151-158
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• 2006

In this paper, we proposed a new audio fingerprint extraction method, based on Philips' music retrieval algorithm, which uses the energy difference of neighboring filter-bank and probabilistic characteristics of music. Since Philips method uses too many filter-banks in limited frequency band, it may cause audio fingerprints to be highly sensitive to additive noises and to have too high correlation between neighboring bands. The proposed method improves robustness to noises by reducing the number of filter-banks while it maintains the discriminative power by representing the energy difference of bands with 2 bits where the quantization levels are determined by probabilistic characteristics. The correlation which exists among 4 different levels in 2 bits is not only utilized in similarity measurement. but also in efficient reduction of searching area. Experiments show that the proposed method is not only more robust to various environmental noises (street, department, car, office, and restaurant), but also takes less time for database search than Philips in the case where music is highly degraded.

• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.48-55
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• 1976

The rate constants of the derivatives of N-(2,4-dinitrophenyl)-benzimidoyl chloride were determined at various pH and a rate equation which can be applied over wide pH range was obtained. The reaction mechanism of hydrolysis of N-(2,4-dinitrophenyl)-benzimidoyl chloride which has not been studied carefully earlier in acidic and basic solution can be fullly explained by the rate equation obtained. The rate equation reveals that, beow pH 7.00, the hydrolysis of benzimidoyl chloride proceeds through $S_N2$ reaction to form a carbonium ion intermediate.Above pH 8.5, however, the hydrolysis proceeds through the $S_N2$ type reaction which depends on hydroxide ion and imidoyl chloride concentration. At pH 7.0∼8.5, two reactions occur competitively.

• Journal of the Korean Dietetic Association
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• v.20 no.2
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• pp.87-98
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• 2014

The purpose of this research was to investigate perception, necessity, and satisfaction of a free foodservice in male middle school students. This study was conducted at male middle schools with paid foodservice (PFS group, 250 students) and with free foodservice (FFS group, 250 students) in Chungnam. Average age of students in the PFS group was 13.1 while that of FFS students was 12.8 years. Exactly 88% of PFS students and 94% of FFS students responded that school foodservice is necessary, which was a significant difference (P<0.05). As the reason for participating in foodservice, about 32% of the PFS students answered the school's request while 33.6% of FFS students answered nutrition, showing a significant difference (P<0.001). Exactly 72.8% of PFS and 96.4% of FFS knew about FFS (P<0.001). More PFS students (86.4%) than FFS students (66%) answered they would not participate in foodservice if the FFS would be introduced and the quality of meal service would deteriorate. After initiation to FFS, there were significant differences in assessment of foodservice: 77.6% of PFS students answered expected that the quality of foodservice would degrade, whereas 74.4% of FFS students answered that quality would not degrade (P<0.001). Satisfaction of foodservice was 2.3 points for FFS students, which was significantly lower than the 2.5 points for PFS students (P<0.001). To sum up assessment of foodservice was positive, whereas satisfaction was not significantly different between PFS and FFS. Based on this research, households, schools, and governments should promote FFS in order to diminish financial pressure for students.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.415.2-415.2
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• 2016

Triboelectric nanogenerator (TENG) is one of ways to convert mechanical energy sound, waves, wind, vibrations, and human motions to available electrical energy. The principal mechanism to generate electrical energy is based on contact electrification on material surface and electrostatic induction between electrodes. The performance of TENG are dependent on amount of the input mechanical energy and characteristics of triboelectric materials. Furthermore, the whole TENG system including mechanical structure and electrical system can effect on output performance of TENG. In this work, we investigated the effect of gear train on output performance and power conversion efficiency (PCE) of TENG under a given input energy. We applied the gear train on mechanical structure to improve the contact rate. We measured the output energy under a constant input energy by controlling the size of the working gear. We prepared gears with gear ratios (rin/rw) of 1, 1.7, and 5. Under the constant input energy, the voltage and current from our gear-based TENG system were enhanced up to the maximum of 3.6 times and 4.4 times, respectively. Also, the PCE was increased up to 7 times at input frequency of 1.5 Hz. In order to understand the effect of kinematic design on TENG system, we performed a capacitor experiment with rectification circuit that provide DC voltage and current. Under the input frequency of 4.5 Hz, we obtained a 3 times enhanced rectifying voltage at a gear ratio of 5. The measured capacitor voltage was enhanced up to about 8 fold in using our TENG system. It is attributed that our gear-based TENG system could improve simultaneously the magnitude as well as the generation time of output power, finally enhancing output energy. Therefore, our gear-based TENG system provided an effective way to enhance the PCE of TENGs operating at a given input energy.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.303-310
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• 2014

The purpose of this study was to identify an effects of Proprioceptive Neuromuscular Facilitation(PNF) on articulator function of the stroke patients. This study evaluated pre- and post- articulator function, targeting the test group for whom an program by PNF was applied, the contrast group for which an articulator training program was applied, and the control group for which no intermediation was made. Each program were performed total 24 times based on 3 times per 30~50 minutes. In result, MPT, AMR ,SMR of the test group were enhanced. AMR of the contrast group did not show any significant difference in /tə/, /rə/, and /a/. Therefore, Program by PNF is informed to have a effect in advancing the articulator function of the stroke patients, especially it was effective of the tongue movement.

• Journal of agricultural medicine and community health
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• v.7 no.1
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• pp.43-49
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• 1982

Clonorchiasis sinensis is one of the most important endemic diseases in Korea, and this disease has been known to be one of public health concern in many areas of Korea. This survey was undertaken to evaluate the status of clonorchiasis in Yeoju Gun, Gyeong-gi Do from July to September 1980. A total of 1,194 male students were examined by intradermal test with Clonorchis antigen. In order to detect Clonorchis egg, the stool examinations were undertaken to 1,158 students, and the intensity of the Clonorchis infection was estimated by the Stoll's egg count. The prevalence rate was reanalyzed by the regional groups for an investigation of regional characteristics of infection. The following results were obtained in this survey. 1) Among 1,194 students in Yeoju Eup, positive rate of intradermal test with C. sinensis antigen was 17.2 percent. (middle school14.6% and high school 20.1%). 2) In the examination of 1,158 stool specimens, Clonorchis eggs were found in 97 (8.4%) cases. 3) Mean E.P.G. of Clonorchis infected case was $1,330{\pm}2,620$. 4) The degree of the intensity of Clonorchis infection by E.P.G. count was distributed as 73.6% in light infection (100-999), 22.6%, in moderate infection (1,000-9,999), and 3.8% in heavy infection (10,000-29,999). 5) High prevalence rate of Clonorchis sinensis was found in the Sang-Ri(9,3%) and Ha-Ri(8.4%) in Yeoju Eup. Neighbouring Bugnae Myun (11.5%), Gangcheon Myun(12.1%) and Neungseo Myun (11.1%) adjacent to the river had a similary high prevalence of C. sinensis.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.181-191
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• 2006

The objectives of this study were to evaluate the tensile strength of resin-infiltrated demineralized dentin according to the demineralization time, and to evaluate the tensile strength of hybrid layer that is formed by infiltrating different priming adhesives or primer/adhesive into demineralizd dentin matrix. Seventy five hour-glass shaped dentin specimens were prepared in mid-coronal dentin from extracted human molars. Thirty specimens were distributed into three groups according to demineralization time - 2 hours, 4 hours and 8 hours. Each specimen was placed in primer/adhesive of All-Bond 2 for 5 hours of infiltration. Another forty-five specimens of them were demineralized in 37% phosphoric acid for 4 hours. They were randomly assigned to three experimental groups - AB, SB and OS - to designate All-Bond 2, Single Bond and One-Step. Each specimen was placed in one of three different adhesives for 5 hours of infiltration. The specimens were visible light-cured for 5 minutes, and then stored for 24 hours in distilled water at $37^{\circ}C$. After that, microtensile bond strength for each specimen was measured, and the fractured surfaces were then observed by SEM. The data were statistically analysed by one-way ANOVA and Tukey's multiple comparison test and Bonferroni's multiple comparison test. The results were as follows; 1. Tensile strength of the group demineralized for 4 hours was significantly higher than that of groups demineralized for 2 hours and 8 hours (P < .01). 3. Tensile strength of the AB group was significantly higher than that of the SB group and OS group (P < .01).

• The Journal of the Korean dental association
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• v.55 no.12
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• pp.850-860
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• 2017

Orthodontic treatment with premolar extraction is usually performed to correct bialveolar protrusion. These methods require the use of stiff rectangular working archwire which requires lengthy alignment and leveling before insertion. In this case report, interproximal reproximation was performed instead of extraction. To establish clearance between the archwire and resin domes fixing the archwire, an archwire was inserted into a water-soluble tube before fabricating resin domes. This tube is solved away by the saliva. During fabrication of resin domes, the archwire was deflected intentionally reflecting the displacement of teeth from their ideal position. This can be called as deflection-based bonding (DBB) technique. DBB is different from conventional method of positioning the brackets on its ideal position and then inserting an archwire to align the brackets. Because the orthodontic force of the archwire comes from its deflection from passive configuration, deflecting an archwire as needed can move the teeth more predictably than just bonding brackets on its ideal position. Also, areas with good alignment before orthodontic treatment can be maintained simply by not deflecting the archwire during bonding in these areas. After initial alignment, interproximal reproximation was performed to create 4.8 mm space in the maxillary arch and 4.2 mm space in the mandibular arch. These spaces were closed using orthodontic mini-implant anchorage thus retracting the maxillary incisors 4 mm posteriorly accompanied with 0.7 mm and 0.3 mm distal movement of right and left molars. By using interproximal reproximation and water-soluble tube with DBB, mild bialveolar protrusion was successfully treated without extraction.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.270-277
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• 1995

The research was carried out in tray in greenhouse equipped with Auto Foggy Systems(SAE KI RIN Co.) and the results were summarized as follows. 1. The number of leaves and fresh weight of Chinese cabbage were not different, but the plant height was increased due to foggy condition. 2. Plant height was decreased in 40 and 60 days of weed competition by foggy condition, the number of leaves was not different. And, shoot fresh weight was decreased by in all the duration of weed competition under foggy condition. Especially, that was greater in 40 days. 3. The shoot fresh weight was decreased by pendimethaline and napropamide application under foggy condition. Also, the number of leaves was decreased at 60 days after transplanting by pendimethaline application under foggy condition. 4. Pendimethalin, napropamide and alachlor treatments were not different in the weeding efficacy between non-foggy and foggy conditions. Trifluraline showed lower weeding efficacy by seedling emergence of large crabgrass as the days of treatment got longer under foggy condition.

• Journal of the Korean Chemical Society
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• v.19 no.1
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• pp.3-10
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• 1975

The partial molal volumes and relative viscosities of tetraethylammonium chloride in a series of dimethyl sulfoxide (DMSO)-water mixtures were measured at $30^{\circ}C$. A maximum structuredness of solvent, that leads to a minimum viscosity A-coefficient and a maximum viscosity B-coefficient of the Jones-Dole equation(${\eta}_r=1+AC^{1/2}$ + BC), was found at 0.2${\sim}$0.3 mole fraction of DMSO. The solvent structure, that leads to a minimum partial molal volume due to the maximum electrostrictive effect of chloride ion and to a minimum viscosity B-coefficient, was found at 0.4${\sim}$0.5 mole fraction of DMSO. An approximate relationship between the limiting effective flowing volume, $V_e^{\circ}$, and the B-coefficient was found to be B = 2.5 $V_e^{\circ}$ in the Einstein equation.