• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.30-36
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• 2006

In this paper, a new type of written image segmentation based on relative comparison of region areas is proposed. The original image is composed of two distinctive regions; information and background. Compared with this binary original image, the observed one is the gray scale which is represented with complex regions with speckles and noise due to degradation or contamination. For applying threshold or statistical approach, there occurs the region-deformation problem in the process of binarization. At first step, the efficient iterated conditional mode (ICM) which takes the lozenge type block is used for regions formation into the binary image. Secondly the information region is estimated through selecting action and restored its primary state. Not only decision of the attachment to a region but also the calculation of the magnitude of its area are carried on at each current pixel iteratively. All region areas are sorted into a set and selected through the decision parameter which is obtained statistically. Our experiments show that these approaches are effective on ink-rubbed copy image (拓本 'Takbon') and efficient at shape restoration. Experiments on gray scale image show promising shape extraction results, comparing with the threshold-segmentation and conventional ICM method.

• Journal of the Korean Chemical Society
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• v.41 no.6
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• pp.292-298
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• 1997

An ICP(Inductively Coupled Plasma) emission spectrometer was developed with an axially viewed ICP source incorporated by a 5-turned induction coil and a torch, outer quartz tube of which was 50 mm longer than that used in conventional ICP/AES(Inductively Coupled Plasma Atomic Emission Spectrometry). The Optimization of the system has been performed in terms of the determination of signal-to-noise ratio and background intensity at various rf powers, sample flow rates, argon gas flow rates and cut-off gas flow rates. The spectro-analytical characteristics of the spectrum obtained between 200 and 500 nm was revealed to be similar compared with a vertically viewed ICP source. The detection limit of Pb(Ⅱ) at 220.35 nm was 11 ppb which was 5 times lower than that obtained with a vertically viewed ICP source.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.617-622
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• 2004

In this work, we suggested the method which improves the efficiency of the face detection algorithm using Pulse-Coupled Neural Network. Face detection algorithm which uses the color information is independent on pose, size and obstruction of a face. But the use of color information encounters some problems arising from skin-tone color in the background, intensity variation within faces, and presence of random noise, and so on. Depending on these conditions, we obtained the mean and variance of the skin-tone colors by experiments. Then we introduce a preprocess that the pixel with a mean value of skin-tone colors has highest level value (255) and the other pixels in the skin-tone region have values between 0 and 255 according to a normal distribution with a variance. This preprocess leads to an easy decision of the linking coefficient of Pulse-Coupled Neural Network.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.87-93
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• 2019

We discuss the design of a radiometer using a millimeterwave(Ka-band) seeker. We applied a total power radiometer, thus the radiometer is composed of a IF-drive amp, band-pass filter, detector and an Op-amp additionally. As a radiometer measure a radiated signal of an object which is noise-like, a radiometer is easily affected by the variance of system temperature. To mitigate an adverse effect, we propose a compensation method in a radiometer without brightmess temperature compensation circuits. Through some experiments such like a distinction a target and the background, we have verified that the designed radiometer system has distingushed a car from the ground completely.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.13 no.2
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• pp.139-144
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• 2002

Background and objectives : The various voice-conserving treatments are used for Tla staged glottic cancer. Especially, Tla staged glottic cancer has been shown excellent treatment result after laser cordectomy or radiotherapy. To evaluate which treatment results better voice after treatment made it valuable to define the exact indication and recommending treatment modality on the Tla staged glottic cancer patients. Method : The medical records of 75 patients with glottic TlaN0 cancer diagnosed at Asan medical center, University of Ulsan college of medicine form May, 1989 to July,2001 were retrospectively reviewed on the point of voice quality and oncology including 5-year survival rate and local control rate. Results : Laser cordectomy and radiotherapy showed 100% and 94.0% 5-year survival rate, respectively. And laser cordectomy had 94.3% local control rate while radiotherapy got 87.6% local control rate. Voice analysis of pretreatment and posttreatment were used to compare each result. Fundamental frequency(F0), shimmer, jitter, noise to harmony ratio(NHR), maximum confortable phonation time(MPT) and vocal efficiency(VE) were used for parameters for voice analysis. Only in shimmer and MPT, we could find significant posttreatment difference between two therapies. In addition, we reviewed the total expenses for each therapy. Conclusion : On the basis of the oncologic result, both the laser cordectomy and radiotherapy had the similar results. Laser cordectomy showed the relatively acceptable voice as radiotherapy did. Laser cordectomy cost less than radiotherapy did. Laser cordectomy can be used for treatment about Tla staged glottic cancer.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.46-50
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• 2000

Background and Objectives : Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documeted subjective vocal changes or documented single cases without detailed, baseline voice assessments. Materials and Methods : We have performed objective voice analyses of 20 women who were treated with androgenic hormones for endometriosis and compared the results with those of normal control women. Results : The averages of fundamental frequency were 194.7${\pm}$28.2 in study group, 207.0${\pm}$14.1 in control group. The means of closed quotient which were measured with electroglottography were 45.13${\pm}$2.06 in study group, 45.1${\pm}$3.03 in control group. Results of acoustic analysis are as follows. The averages of jitter were 0.95${\pm}$0.46 in study group, 1.10${\pm}$0.65 in control group. The means of shimmer were 2.44${\pm}$0.60 in study group, 2.32${\pm}$1.09 in control group. The averages of noise to harmonic ratio were 0.13${\pm}$0.028 in study group, 0.15$\pm$0.18 in control group. Conclusion : Although there were no statistically meaningful differences between the two groups, we could detect the masculinizing tendency of the therapeutic hormones of endomentriosiss(lowering of fundamental frequency). Given the availability of objective voice assessments today and the continued use of these potent hormones, comprehensive voice assessment and vocal monitoring would appear vital for women commencing hormonal treatment.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.1
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• pp.37-40
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• 2018

Background and Objectives : This study aimed to evaluate patients' subjective and objective outcomes after laryngeal microsurgery for benign vocal fold (VF) lesions, and to identify usefulness of surgical treatment. Materials and Methods : The authors reviewed the 102 patients medical records, retrospectively who received laryngeal microsurgery for benign VF lesions from January 2013 to August 2017. Subjective voice were measured using the Voice Handicap Index (VHI). Objective voice were recorded with Multi-Dimensional Voice Program (MDVP) just before surgery, and after at least 3 months of surgery. Results : Benign VF lesions were categorized as VF nodule (n=34, 33%), VF Polyp (n=47, 26%), Intracordal cyst (n=15, 15%), Reinke's edema (n=6, 6%), and VF Papilloma (n=2, 2%). Post-operative voice assessment at VHI scores showed statistically significant reductions in all of functional, physical and emotional parts (p<0.001). MDVP were showed significant improvement of Jitter (P=0.001), Shimmer (p<0.001) and Noise to Harmonic Ratio (NHR) (p=0.001). Conclusion : Laryngeal microsurgery for benign vocal fold lesions is effective treatment with statistically significant improvement at subjective and objective vocal quality assessment.

• Journal of Yeungnam Medical Science
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• v.17 no.2
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• pp.108-122
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• 2000

Background: Models of attention deficit hyperactivity disorder(ADHD) that have proposed a hypodopaminergic state resulting in hypofunction of the prefrontal circuitry have assumed a unitary dopamine system, which largely ignores the distinct functional differences between mesocortical dopamine system and nigrostriatal dopamine system. Purpose: The author's goal was to develop a pathophysiological model for ADHD with greater explanotory power than dopaminergic hypofunction hypothesis in prefronal circuitry. Material and Methods: Published clinical findings on ADHD were integrated with data from genetic, pharmacological, neuroimaging studies in human and animals. Results: Molecular genetic studies suggest that three genes may increase the susceptibility to ADHD. The three candidate genes associated with ADHD are each involved in dopaminergic function, and this consistent with the neurobiologic studies implicating catecholamines in the etiology of ADHD. Pharmacological data also provide compelling support for dopamine and noradrenergic hypothesis of ADHD. Neuroimaging studies lend substantial support for the hypothesis that right-sided abnormalities of prefrontal-basal ganglia circuit would be found in ADHD. Conclusions: The present hypothesis takes advantage of the major differences between the two pertinent dopamine systems. Mesocortical dopamine system, which largely lacks inhibitory autoreceptors, is ideally positioned to regulate cortical inputs, thus improving the signal-to-noise ratio for biologically valued signals. In this circuit, therapeutic doses of stimulants are hypothesized to increase postsynaptic dopamine effects and enhance executive functions. By contrast, symptoms of hyperactivity/impulsivity in ADHD are hypothesized to be associated with relative overactivity of nigrostriatal circuit. This nigrostriatal circuit is tightly regulated by inhibitory autoreceptoors as well as by long distance feedback from the cortex, and slow diffusion of therapeutic doses of stimulant via oral administration is hypothesized to produce a net inhibition of dopaminergic neurotransmission and improves hyperactivity.

• The Journal of the Acoustical Society of Korea
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• v.13 no.5
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• pp.32-39
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• 1994

The speech transmission quality in telephone is quantified in terms of loudness rating, but this method has been validated only for the handset telephony. The transmission quality of loudspeaking telephony in any room must be evaluated not only with speech transmission but also with background noise, echo and reverberation since the effect of room acoustics is much stroger for loudspeaking telephoy. Therefore, it requires a better approach to specify the quality of loudspeaking telephony. By calcuating the speech transmission index (STI), a physical method for measuring the quality of speech transmission was proposed by Steeneken. In this paper, the application of a STI method for estimating articulation of loudspeaking telephony was discussed. And the STI measurement system with high speed calculation was also three rooms, having different reverberation times. The result show that the STI decreases as the reverberation time of rooms increases. It suggests that speech transmission index method can be useful evaluating articulation of a loudspeaking telephony including the sound field characteristics.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.210-216
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• 2013

It is hard to listen to the music clearly in the presence of background noise. In this paper, a method that modifies the audio signal automatically to enhance the audio listening experience in adverse environment is proposed. Specifically, the method that amplifies the audio signal so that the perceived loudness of audio signal in each band becomes similar to that of the noiseless signal. The loudness perception model proposed by Moore et. al is utilized. Extending the previous work that is applied to speech reinforcement, the full band signal sampled at 48kHz is manipulated based on the loudness restoration principle. Moreover, based on the observation that the audio clarity is compromised even with loudness restored signal, a modification that intentionally boosts high frequency loudness more than lower band is also proposed. Experimental results showed that the proposed algorithm can enhance the audio listening experience in adverse environment.