• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.11 no.1
• /
• pp.18-30
• /
• 1999

A heat transfer analysis for the two-dimensional (2-D) steady state using finite difference method (FDM) is performed to predict the thermal behavior of the primary first-wall (FW) system of fusion reactor under various geometric and thermo-hydraulic conditions, such as the beryllium (Be) armor thickness, pitch of cooling tube, and coolant velocity. The FW consists of authentic steel (type 316 stainless steel solution annealed) for cooling tubes, Cu for cooling tubes embedding material, and Be for a protective armor, based on the International Thermonuclear Experiment Reactor (ITER) report. The present 2-D analysis, the control volume discretized with hybrid grid (rectangular grid and polar grid) and Gauss-Seidel iteration method are adapted to solve the governing equations. In the present study, geometric and thermo-hydraulic parameters are optimized with consideration of several limitations. Consequently, it is suggested that the adequate pitch of cooling tube is 22-32mm, the beryllium armor thickness is 10-12mm, and that the coolant velocity is 4.5m/s-6m/s for $100^{\circ}C$ of inlet coolant temperature. The cooling tube should locate near beryllium armor. But, it would be better for locating the center of Cu wall, considering problems of material and manufacturing. Also, 2-D analysis neglecting the axial temperature distribution of cooling tube is appropriate, regarding the discretization error in axial direction.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.317-322
• /
• 2008

The objectives of this paper are to study the effects of thermal and geometric conditions on the performance of indoor heat exchanger with R410A for Gas Engine Driven Heat Pump (GHP) application and to find optimum design conditions of indoor heat exchanger by parametric analysis for the key parameters. In the air side, moisture out of the humid air condenses on the fin surface while the refrigerant (R410A) boils inside the smooth tube. Therefore this study uses Log Mean Enthalpy Difference (LMHD) method to analyze the heat transfer from the humid air to the refrigerant of R410A. The results show that fin pitch and longitudinal pitch have significant effect on the heat exchanger preformance. This study will provide the guideline for optimum design of indoor heat exchanger with R410A for GHP application.

• Speech Sciences
• /
• v.12 no.4
• /
• pp.141-152
• /
• 2005

This paper shows the tonal patterns of English conjunctive utterances produced by Korean speakers of English, presenting that Korean speakers realize either the H - phrase tone or the H% boundary tone at the phrase-final part of the conjunctive utterances. Based on Pierrehumbert & Hirschberg's (1990) claim that either H- or H% tone indicates that a phrase is related to the following one, Korean speakers seem to produce the satisfactory patterns of edge tones in conjunctive sentences. In the experiment, we made up conjunctive sentences including both coordinate conjunctions such as and, but, or, and so and subordinate conjunctions like if, when and though. We varied the stimuli according to the existence of a comma and the lengths of connecting words and phrases. We also divided the subjects into two levels of English proficiency based on their English written test scores to see if Korean speakers' performance ability of edge tones is related with their general competence of English. Results show that Korean speakers produced 84% of the H- phrase tone in intermediate phrases and H-L% and L-H% boundary tones in intonational phrases. Also, coordinate and subordinate conjunctions show little difference in their tonal contours, and the existence of a comma or the lengths of connecting words and phrases do not affect Korean speakers' production of the H- phrasal tone and the H% boundary tone. This may suggest that pitch accents, rather than edge tones, should be put more focus on in teaching English intonation in Korea as much work has already shown that Korean speakers have serious problem with producing pitch accents in speaking English.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.12 no.1
• /
• pp.47-58
• /
• 1975

The effect of the bow shape on the ship motion response among longitudinal regular waves, is investigated employing the strip theory. The two dimensional hydrodynamic forces such as added mass and damping are calculated by the integral equation method for arbitrary sections. Nine ship models are selected for investigation. They are U, UV and V bow ship forms of different block coefficient of 0.6, 0.7 and 0.8 with constant after body. The heave amplitude of the V bow ship is smaller than that of the U bow ship in the whole range of wave length except extremely short wave as were stated by the earlier investigators. This results holds also in the case of bow vertical motions such as vertical relative displacement, velocity and acceralation. As to the pitch amplitudes, the V bow ship gives smaller value in long waves but larger value in short waves. However, heave and pitch phase angles are practically not influenced by the form of the fore body sections. In the bow motions, a little difference in phase angle is appeared in the vicinity of the wave which has same ship length. With respect to the wave exiting force and moment unfovourable effects could be expected in V bow ships. And these tendency hold also in the wave bending moment.

• Speech Sciences
• /
• v.10 no.1
• /
• pp.15-25
• /
• 2003

A laryngograph was developed to measure the open and closed movements of vocal folds in our laboratory. This study attempted to evaluate its performance by comparing its glottal data with that of the original laryngograph. Ten normal Korean adults Participated in the experiment. Each subject produced a sustained vowel /a/ for about five seconds. This study compared f0 values, contact quotients of the duration of closed vocal folds over one glottal pulse, and area quotients of the closed over open vocal folds derived from glottal waves using both the original and new laryngographs. Results showed that the mean and standard deviation of the two laryngographs were almost comparable with a correlation coefficient 0.662 but minor systematic shift below those of the original laryngograph was observed. The absolute mean difference converged into 1 Hz, which indicates a possibility of adopting some threshold of rejecting inappropriate pitch values beyond a threshold value. The contact quotient of the normal subjects came out slightly over the 50% in a citation speech. Finally, the area quotient converged into 1. We will pursue further studies on the abnormal patients in the future.

• Phonetics and Speech Sciences
• /
• v.2 no.2
• /
• pp.117-121
• /
• 2010

The This study aimed to evaluate the effects of the voice therapy we operated to the patients with age-related dysphonia. Thirty four participants who were diagnosed as age-related dysphonia in laryngoscopic finding from January, 2009 to December, 2009 completed the study. The participants were aged from 60 to 82 years old with a mean age of 70.6. All participants had received the abdominal breath technique, SKHPIP with laughter, and basic vocal training with description of their problem, the length of which ranged from four sessions to twelve sessions. We executed the videostroboscopy to compare the aspect of voicing change and the perceptual assessment, voice range profile, acoustic and aerodynamic measures to identify change of voice. Participants had glottal gap due to incomplete glottic closure during voicing on the pretest. After they took the voice therapy, the glottic gap became narrow and rough and breathy voice was reduced. There were significant difference in acoustic and aerodynamic measures. Jitter, Shimmer, MFR were reduced and MPT, Psub were increased(p<.05). Participants' pitch range and intensity range were increased on the posttest performance after taking voice therapy. Especially, most of them were showed that pitch range was increased significantly in high frequency area. The results of this investigation indicate that the voice therapy using abdominal breath, SKHPIP, and exercise together is effective for the patients who have age-related dysphonia to improve their voice quality. We recommend to apply this technique to functional voice disorders who are showed glottal gap.

• Progress in Superconductivity and Cryogenics
• /
• v.23 no.4
• /
• pp.25-29
• /
• 2021

For the application of HTS wire to AC power equipment, a conductor with high current capacity and low loss is required. CORC^®, one of the high-current conductors manufactured using several HTS wires, is made by winding the wires in a spiral on a cylindrical former. Because the magnetization loss of a CORC^® conductor depends on the degree of magnetic coupling between the wires constituting the CORC^®, it is necessary to know the value of the magnetization loss of the CORC^® itself. In order to obtain an accurate loss value, it is necessary to know the effect of the ratio of the winding pitch of the CORC^® conductor in the pickup coil region sampling the magnetization loss signal. To confirm this effect, we prepare CORC^® samples having various winding pitches, and measure and compare the magnetization losses. In addition, the magnetization loss was measured while rotating the CORC^® samples and it was examined whether there was a difference in the magnetization loss according to the rotation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.10
• /
• pp.1276-1283
• /
• 2016

The scale of financial damages on voice fishing has not been decreased despite of national and social efforts to reduce the amounts of voice fishing damage. One of these reasons is a sophisticated and vernacular speech style that makes it difficult to recognize the offenders. Furthermore, nowadays, young men have intensively been deceived by not only sophisticated and vernacular speech style which is used the employer of real public offices but also obtained personal information. As a result, this lead directly to the financial damages of younger people who has a stronger judgement than older. For this, we investigated the comparison and analysis between the criminals of voice fishing and the same generation younger people for identifying voice features. The experiment was carried out based on the pitch, bandwidth of pitch, energy, speech speed and voice color for searching the difference of voice characteristics between the criminals of voice fishing and the same generation younger people since 2011. The experimental result shows that there is a significant difference in energy and speech speed between the criminals of voice fishing and the same generation younger people.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1994.06c
• /
• pp.107-110
• /
• 1994

In this paper, we describe the features of the fundamental frequency contour of Korean read speech, and propose a new stylization method to characterize the Fø pattern of segments. Our algorithm consists of three stylization processes : the segment level, the syllable level, and the sord level. For stylization of Fø contour in the segment level , we applied least square error minimization method to determine Fø values at initial, medial, and final position in a segment. In the syllable level, we determine the stylized Fø pattern of a syllable using the mean Fø value of each word and style information for each word, syllable and segment, we reconstruct Fø contour of sentences. The simulation results show that the error is less than 10% of the actual Fø contour for each sentence. In perception test, there is little difference between the synthesized speech with the original difference between the synthesized speech with the original Fø contour and the synthesized speech with the stylized Fø contour.

• Journal of Sasang Constitutional Medicine
• /
• v.12 no.1
• /
• pp.144-156
• /
• 2000

Purpose of this study is to help classifying Sasang Constitution through correlation with Larynx waveform. This study was done it under the suppose that Sasang Constitution would be correlation with Larynx waveform. The following result were obtained about correlation between Erectroglottograph waveform and Sasang Constitution by analysis EGG program. 1. Taeumin was lower than Soyangin in Open Std Deviation, Contact Std Deviation of male/a/(0.5sec) 2. Soeyangin was high compared with the others in Pitch range of maie/a/(2.5sec) 3. Taeumin was higher than Soeumin in Pitch range, Soeyangin in pitch Maximum, and the others in Pitch Std Deviation of female/e/(0.5sec) 4. Taeumin was higher than Soeumin in Contact Maximum and lower than Soeumin in Contact Maximum of female/a/(2.5sec) 5. There was no significantly difference in male/e/(0.5sec), male/e/(2.5sce), female/a/(0.5sec), female/e/(2.5sec) 6. The percent of correctly classified in Soeoumin and Taeumin was high in CART Algolism. The risk estimate of Soyangin was relatively high. The study may be use on of the method to make objective diagnosis in Sasang constitution.