• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.10.1-10
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• 1982

The use of phonosurgery in the recent development of laryngomicrosurgery has enabled the restoration of a normal voice in respect to functional laryngeal surgery which in Korea in the past limited to simple removal of benign laryngeal tumor such as laryngeal polyp or nodules and cordal injection of $Teflon^{{\circledR}}$ for the treatment of recurrent nerve paralysis under the vision of suspension laryngoscopy. Performance of phonosurgery for the treatment of cord paralysis, mutational dysphonia, vocal cord atrophy, hyperkinetic dysphonia and sulcus vocalis is a happy event in the view point of development of phonosurgery in Korea. In this aspect thyroplasty to change the position and physical characteristics of the cord outside the glottis instead of the direct handling of the vocal cord through direct endoscopy is popular. Among the 4 types of thyroplasty, classified by Insshiki(1974), type I thyroplasty(1ateral compression of vocal cord) and type IV thyroplasty(lengthening of vocal cord) were effective in the treatment of unilateral vocal cord paralysis. Advantages of this operation are the fine adjustment of the degree of lateral compression under local anesthesia according to the phonation of the patient during operation and avoidance of dyspnea and intralaryngeal hemorrhage due to the manipulation outside the internal perichondrium of the thyroid cartilage. We did 7 cases of thyroplasty for the treatment of unilateral vocal cord paralysis in the 7 months from September 1981 to March 1982. Before the operation aerodynamic study, psychoacoustical evaluation, stroboscopy and sound spectrographic analysis were done. Two months after the operation the above procedures were performed again. Results of preoperative and postoperative examination were compared and the following results were obtained. 1) In the aerodynamic study, maximum phonation time increased to 158% of the preoperative value and the phonation quotient and the mean flow rate decreased to 58% and 54% of preoperative values. 2) The degree of hoarseness improved in the psychoacoustical evaluation and the glottic chink during phonation was decreased in the stroboscopic examiantion. 3) In the sound spectrographic analysis, periodicity was much restored and noise distribution decreased especially in the high frequency area.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.122-129
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• 2020

Surion is required to install radios (U/VHF-AM, VHF-FM) capable of omni-directional communication. Therefore, this paper demonstrates the antenna performance test for the installation of the Surion communication antenna and the selection of optimal location. A simulation pattern analysis was performed employing the antenna, and a coupling test was performed by creating a new evaluation criterion. In addition, the results of the pattern flight test conducted at the previously suggested 1:20 turn and separation distance ratio were observed to be normal. However, the occurrence of voice cutoff was noted in the long-distance flight test. Therefore, in this paper, 1:300 (15 NM) is proposed as a new optimal ratio for predicting the long-distance flight test results in advance. Finally, the effectiveness of the proposed evaluation criteria was verified through long-distance flight tests. Consequently, it is expected to reduce the development schedule and cost by reducing the trial and error of the performance test for the Surion model. Also, the results of this study are expected to be used as standards for the installation of communication antenna and quality tests for other helicopters.

• Journal of Service Research and Studies
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• v.5 no.2
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• pp.111-118
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• 2015

Although the development of mobile devices are made us a free life, they were displayed the subject of this financial crime and attacking forces in the other side. Among finance-related crime is become a serious crime that are targeting smartphones by SMS phishing, phishing, pharming, voice phishing etc. In particular, SMS phishing is increased according to phenomenon using the nature of a text message in the mobile. SMS phishing is become new crime due to the burden to the smartphone user. Their crime is also the advanced way from the existing fraud, such as making the malicious apps. Especially it generates loopholes in the law by a method such as using a foreign server. For safe from SMS phishing attacks, proactive pre-diagnosis is even more important rather than post responses. It is necessary to deploy blocking programs for detecting SMS phishing attacks in advance to do this. In this paper we are investigating the process of block types and block apps that are currently deployed and presenting the evaluation of the application of the detection block setting app.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.8.2-9
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• 1983

Recently, the laryngomicrosurgery has been done for the removal of benign laryngeal mass and for the improvement of voice. For the evaluation of the effect of the treatment, there must be any objective method such as aerodynamic study, vocal fold vibration study, acoustic analysis, psycho-acoustic evaluation and the neuro-muscular study. The authors evaluated the phoniatric effect of the laryngomicrosurgery for the patients of 15 laryngeal polyps and 9 laryngeal nodules, who received pre-op. and post-op. vocal function study from Jun. 1981 to Mar. 1983. The results obtained were as follows ; 1) The post-op. mean value of the maximum phonation time was increased 40 % in the unilateral polyps, 62 % in the bilateral nodules and 18 % in the unilateral nodules. 2) The post-op. mean value of the phonation quotient was decreased 25 % in comparison with pre-op. value in the case of the bilateral polyps, 26 % in the unilateral polyps, 55 % in the bilateral nodules and 12 % in the unilateral nodules. 3) The post-op. mean value of the mean air flow rate was decreased 27 % in comparison with the pre-op. value in the case of the bilateral polyps, 25 % in the unilateral polyps, 65 % in the bilateral nodules, 25 % in the unilateral nodules. 4) The glottic chink of the 10 cases of polyps among the 11 cases were disappeared, and the glottic chink of the 5 cases of nodules among 7 cases were also disappeared after surgery. 5) The pre-op. hoarseness of the 10 cases of polyps among the pre-op. hoarseness of the 11 cases of polyps were changed to clear and the 3 cases of nodules were also changed to clear.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2A
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• pp.152-161
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• 2007

IEEE 802.11 Wireless Local Area Network (WLAN) became a prevailing technology for the broadband wireless Internet access, and new applications such as Voice over WLAM (VoWLAN) are fast emerging today. For the battery-powered VoWLAN devices, the standby time extension is a key concern for the market acceptance while today's 802.11 is not optimized for such an operation. In this paper, we propose a novel Idle Mode operation, which comprises paging, idle handoff, and delayed handoff. Under the idle mode operation, a Mobile Host (MH) does not need to perform a handoff within a predefined Paging Area (PA). Only when the MH enters a new PA, an idle handoff is performed with a minimum level of signaling. Due to the absence of such an idle mode operation, both IP paging and Power Saving Mode (PSM) have been considered the alternatives so far even though they are not efficient approaches. We implement our proposed scheme in order to prove the feasibility. The implemented prototype demonstrates that the proposed scheme outperforms the legacy alternatives with respect to energy consumption, thus extending the standby time.

• Journal of Internet Computing and Services
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• v.11 no.3
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• pp.87-103
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• 2010

In the study, we introduce the trend in domestic and foreign web accessibility, as well as the legal system that ensures web accessibility. Based on Korean Web Content Accessibility Guidelines (KWCAG)1.0, we investigated the web content accessibility of 80 tertiary health-care hospitals and general hospitals in Korea. We evaluated accessibility by combining accessibility-based criteria (ABC) with usability-based criteria (UBC). ABC was limited to an alternative text for Guideline 1, using a small number of frames and keyboard accessibility for Guideline 2. UBC checked the voice service (TTS), resizing text, providing multi-lingual websites, and disclosing web accessibility policy. KADO-WAH2.0 was used for representing the compliance rate. The evaluation result was a considerable improvement from previous results, even though the rate of compliance with web accessibility was generally insufficient. There was a significant difference between those medical centers which did and did not comply with web accessibility. Incidentally, many hospitals were found to have attempted to confront and come to terms with web accessibility. In future, the following factors are advisable for medical centers with publicity or public interest: they must employ active and aggressive promotion of establishment of independent accessibility guidelines to secure web accessibility, they should effect an improvement of the realization of web accessibility, there can be constant education and promotion, and there can be an institutional supplementation, as well as others.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.582-588
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• 2014

IMO and IALA have undertaken projects that GMDSS Modernization and E-navigation, which refer to "Future digital communications systems" for a more efficient transmission of voice and data communications in the VHF maritime mobile service. ITU has also resolved in WRC-07 Resolution 357 to study the use of spectrum-efficient technologies in order to provide for the operation of ship and port security and maritime safety systems. IALA and ITU WP5B have coordinated for the technical developments and the spectrum issues. Recommendation ITU-R M.1842-1 has approved by WP5B meeting. This revision provides a wideband data service both 50kHz and 100kHz in the VHF maritime mobile service. This paper has studied E-navigation, its needs for data exchange that includes explanations of the current methods for transmitting data by VHF that based in land mobile radio service. A further technologies trend is estimated for Recommendation ITU-R M.1842-1, that is based on the land mobile radio standards with some tailored to fit the needs of the maritime mobile service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3048-3056
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• 2012

The purpose of this study was to investigate VHI, V-RQOL, and vocal characteristics of a teacher and singer. 56 subjects were participated in this study (20 subjects are a teacher with vocal nodule, 20 subjects are a singer with vocal nodule, and 16 subjects are normal speakers). All subjects completed the VHI, V-RQOL, and vocal characteristics were measured using CSL 4500(Kay Pentax. USA). 21 subjects completed the VHI, V-RQOL, and vocal evaluation using CSL 4500 twice to assess test-retest reliability. A statistical analysis was performed using the Statistical Package for Social Sciences 18.0 (SPSS Inc, Chicago, IL). The VHI and V-RQOL showed that the teacher and singer group were significantly higher than those of the control group in functional, physical and emotional aspects(p<0.05). the acoustic analysis using CSL 4500 showed the teacher and singer group were significantly higher than those of the the control group in fundamental frequency related variables, fundamental perturbation related variables, amplitude perturbation related variables, noise related variable, and tremor related variables(p<0.05). Conclusionally, the teacher and singer group recognized their voice problems as a serious physico-functional aspects.

• The Journal of the Acoustical Society of Korea
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• v.30 no.8
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• pp.410-420
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• 2011

The present study aims to investigate the soundscapes of Jeju olle route through the soundwalking. In order to do this, sound measurements and sound recording were undertaken at 10 points along Jeju olle route. Also, loudness of background sound and figure sound were examined. Subjective surveys were carried out using questionnaire and interviews with 32 tourists and 5 acoustical specialists in order to investigate the loudest sound, most pleasant and unpleasant sound, and impressive sound among 17 natural and artificial sounds. Additionally, laboratory experiments were achieved to evaluates sound that have been recorded at the field using same questionnaire and the results were compared with those of field experiments. As a result, the sound heard most in Jeju olle route is the sea wave sound, wind sound, automobile noise, and human voice. It was revealed that the most pleasant sound consisted of nature sound among them, and that unpleasant sounds are artificial sounds. The results of subjective test denote that unpleasant sound is affected by ratio of artificial sound and nature sound. And this also affects the assessment about the loudness of the sound. Also, it was found that the results of both field test and laboratory test are closely correlated in the evaluation of loudness of sound and unpleasant feeling.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.661-667
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• 2018

Tactical communication radio systems that employ software defined radios(SDRs) have been developed for achieving high-speed data transmissions and voice communications. Such systems possess multiband and multichannel features, and can potentially replace several existing radio systems. This paper proposes a design for wideband antennas by incorporating a diplexer matching network for tactical vehicles. The proposed antenna design includes two radiators(upper and lower) and a diplexer matching network connected to the end of the feed line such that the LC matching networks are interleaved in the lower radiator and spring mount. By employing the diplexer matching network, the designed antenna can perform wideband impedance matching for the fifty ohm feed line. The designed LC networks aid in varying the effective electrical length of the antenna according to the operation frequency. The primary objective behind adjusting the electrical length is to vary the current distribution above and below the LC networks. The proposed antenna was fabricated and tested in an open site. The obtained evaluation results show that the designed antenna can achieve a relative bandwidth of 190% with a VSWR value of 3.5:1, and can attain good antenna gains over VHF and UHF bands.