• 한국발생생물학회지:발생과생식
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• 제23권1호
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• pp.63-72
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• 2019

The head gap gene buttonhead (btd) is required for the patterning of head segments in the early Drosophila embryo. Mutant phenotypes of btd display a gap-like phenotype in which antennal, intercalary, mandibular and the anterior portion of the maxillary segments are eliminated. In agreement with the phenotypes, btd is expressed in a stripe covering the head segments at the blastoderm stage. During the early phase of the germband extension, btd is expressed in stripes with single segmental periodicity, which is required for the formation of the peripheral nervous system. In contrast to the key role of btd in Drosophila embryonic development, it has been suggested that Tribolium ortholog of btd (Tc-btd) is dispensable for embryonic head development. In order for better understanding of the requirement of Tc-btd in the early Tribolium embryo, we re-analyzed the expression patterns and functions of Tc-btd during embryonic segmentation. Tc-btd is expressed in segmental stripes at the stages of blastoderm and germband elongation. Up to 28.3% of embryos in which Tc-btd is knocked down displays the loss of antennal, mandibular and the pregnathal regions in the head, with abdominal segments being disrupted in the trunk. Our findings suggest that Tc-btd is required for the head and trunk development in the early Tribolium embryo.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1051-1059
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• 2018

Fast periodic pulsed reactor is a type of reactor in which the fission bursts are formed entirely with external reactivity modulation with a specified time periodicity. This type of reactors could generate much larger intensity of neutron beams for experimental use, compared with the steady state reactors. In the design of fast periodic pulsed reactors, the time dependent simulation of the power pulse is majorly based on a point kinetic model, which is known to have limitations. A more accurate calculation method is desired for the design analyses of fast periodic pulsed reactors. Monte Carlo computer code MCNP6 is used for this task due to its three dimensional transport capability with a continuous energy library. Some new routines were added to simulate the rotation of the movable reflector parts in the time dependent calculation. Fast periodic pulsed reactor IBR-2M was utilized to validate the new routines. This reactor is periodically in prompt supercritical state, which lasts for ${\sim}400{\mu}s$, during the equilibrium state. This generates long neutron fission chains, which requires tremendously large amount of computation time during Monte Carlo simulations. Russian Roulette was applied for these very long neutron chains in MCNP6 calculation, combined with other approaches to improve the efficiency of the simulations. In the power pulse of the IBR-2M at equilibrium state, there is some discrepancy between the experimental measurements and the calculated results using the point kinetics model. MCNP6 results matches better the experimental measurements, which shows the merit of using MCNP6 calculation relative to the point kinetics model.

• Journal of applied mathematics & informatics
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• 제39권3_4호
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• pp.381-403
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• 2021

Consider the three-dimensional system of difference equations $x_{n+1}=\frac{{\prod_{j=0}^{k}}z_n-3j}{{\prod_{j=1}^{k}}x_n-(3j-1)\;\(a_n+b_n{\prod_{j=0}^{k}}z_n-3j\)}$, $y_{n+1}=\frac{{\prod_{j=0}^{k}}x_n-3j}{{\prod_{j=1}^{k}}y_n-(3j-1)\;\(c_n+d_n{\prod_{j=0}^{k}}x_n-3j\)}$, $z_{n+1}=\frac{{\prod_{j=0}^{k}}y_n-3j}{{\prod_{j=1}^{k}}z_n-(3j-1)\;\(e_n+f_n{\prod_{j=0}^{k}}y_n-3j\)}$, n ∈ ℕ₀, where k ∈ ℕ₀, the sequences $(a_n)_{n{\in}{\mathbb{N}}_0$, $(b_n)_{n{\in}{\mathbb{N}}_0$, $(c_n)_{n{\in}{\mathbb{N}}_0$, $(d_n)_{n{\in}{\mathbb{N}}_0$, $(e_n)_{n{\in}{\mathbb{N}}_0$, $(f_n)_{n{\in}{\mathbb{N}}_0$ and the initial values x_-3k, x_-3k+1, …, x₀, y_-3k, y_-3k+1, …, y₀, z_-3k, z_-3k+1, …, z₀ are real numbers. In this work, we give explicit formulas for the well defined solutions of the above system. Also, the forbidden set of solution of the system is found. For the constant case, a result on the existence of periodic solutions is provided and the asymptotic behavior of the solutions is investigated in detail.

• 한국ITS학회 논문지
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• 제20권6호
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• pp.1-13
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• 2021

본 연구에서는 도로교통분야의 계획, 설계, 유지관리, 연구 등 다양한 목적으로 활용되고 있는 교통량 데이터의 정확도 확보를 위해 시계열 분석 기법을 적용하여 교통량 데이터의 보정 및 예측을 수행하였다. 기존 알고리즘의 경우 주기성 및 계절성이 강하거나 불규칙한 데이터에 한계를 보이고 있어 교통량 데이터와 같은 자료에 적용하기에는 한계가 있다. 이러한 한계점을 극복하고 보완하기 위해 ARIMA 모형에 자기상관 모형인 SAR(Seasonal Auto Regressive)과 계절 이동평균 모형인 SMA(Seasonal Moving Average)가 결합된 분석 기법인 SARIMA 모형을 적용하였다. 분석결과 최적 파라미터 조합인 SARIMA(4,1,3)(4,0,3) 12 모형을 활용한 교통량 예측 결과 평균 85% 정도의 우수한 성능을 보였다. 본 연구를 통해서 교통량 데이터의 결측 발생 시 교통량 보정 및 예측의 정확도를 높일 수 있으며, 교통량 데이터 외에도 계절성에 영향을 받는 시계열 데이터에 적용이 가능하다.

• Steel and Composite Structures
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• 제44권5호
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• pp.619-632
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• 2022

There are numerous structural details (Longitudinal beam, web plate, U-ribs and I-ribs) in the top and bottom plates of steel box girders, which have significant influences on the longitudinal stress (normal stress) distribution. Clarifying the influence of these structural details on the normal stress distribution is important. In this paper, the ultra-wide steel box girder with large cantilevers of the Jinhai Bridge in China, which is the widest cable-stayed bridge in the world, has been analyzed. A 1:4.5 scale laboratory model of the steel box girder has been manufactured, and the influence of structural details on the normal stress distribution in the top and bottom plates for four different load cases has been analyzed in detail. Furthermore, a three-dimensional finite element model has been established to further investigate the influence regularity of structural details on the normal stress. The experimental and finite element analysis (FEA) results have shown that different structural details of the top and bottom plates have varying effects on the normal stress distribution. Notably, the U-ribs and I-ribs of the top and bottom plates introduce periodicity to the normal stress distribution. The period of the influence of U-ribs on the normal stress distribution is the sum of the single U-rib width and the U-rib spacing, and that of the influence of I-ribs on the normal stress distribution is equal to the spacing of the I-ribs. Furthermore, the same structural details but located at different positions, will have a different effect on the normal stress distribution.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.28-35
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• 2023

Moiré patterns emerge due to the interference between the non-emission area of the LED screen and the grid line in an image sensor of a video recording device when taking a video in the presence of the LED screen. To reduce the moiré intensity, we have fabricated an anti-moiré filter using hollow glass microspheres (HGMs) by slot-die coating. The LED screen has a large non-emission area because of a large pitch (distance between LED chips), causing more severe moiré phenomenon, compared with a display panel having a very narrow black matrix (BM). It is shown that HGMs diffuse light in such a way that the periodicity of the screen is broken and thus the moiré intensity weakens. To quantitatively analyze its moiré suppression capability, we have calculated the spatial frequencies of the moiré fringes using fast Fourier transform. It is addressed that the moiré phenomenon is suppressed and thus the amplitude of each discrete spatial frequency term is reduced as the HGM concentration is increased. Using the filter with the HGM concentration of 9 wt%, the moiré fringes appeared depending sensitively on the distance between the LED screen and the camera are almost completely removed and the visibility of a nature image is enhanced at a sacrifice of luminance.

• 한국군사과학기술학회지
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• 제27권3호
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• pp.311-318
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• 2024

In this paper, a design for a radio frequency(RF) and infrared(IR) absorber with metasurfaces is discussed in microwave frequency bands. The RF absorber includes double layers of metasurfaces to operate in S- and X-bands. Effects of sheet resistance of the metasurfaces and thicknesses of dielectric supporting layers on reflection responses are investigated. An IR stealth layer incorporates an array of conductive grids with slits to reflect IR signals but to transmit RF signals and visible rays. Periodicity of the grids and slits is studied for transmission responses in the X-band and a surface area ratio. Reflection responses of the RF/IR multispectral absorber are found to be lower than -10 dB and -16 dB in the S- and X-bands, respectively, from full-wave simulation. Finally, the RF/IR multispectral absorber is fabricated and its reflection responses are measured to verify designed performance.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1982년도 제16차 학술대회연제순서 및 초록
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• pp.10.1-10
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• 1982

최근의 후두미세수술 (Laryngo-microsurgery)의 보편화와 이에 따른 음성외과학(phonosurgery)의 발달로 종전까지 성대결절이나 성대폴립등의 양성종양 절제나 반회신경 마비등예에서 진단된 성문간격 (glottic chink)을 $Teflon^{{\circledR}}$ injection등으로 치료해오던 후두경술(Laryngoscopy)하에서의 수술적 조작이 그 한계와 범위를 넘어서서 이제는 우리 나라에 있어서도 후두의 기능외과적인 측면에서 음성을 개선하려는 시도가 고조되고 있으며 특히 성대마비나 변성기발성장애 (Mutational dysphonia), 성대위축 (Vocal cord atrophy), 운동기능 항진성발성장애 (Hyperkinetic dysphonia), 성대구증(Sulcus vocalis)등을 위한 음성개선수술이 실시되고 있음은 우리나라의 음성외과학의 발전이라는 견지에서도 매우 기꺼운 일이다. 이러한 뜻에서 내시경술을 통해서 성대에 직접 수술적 조작을 가하지않고서도 성문외적으로 후두구조를 수술하여 성대의 위치와 물리적 성질을 변화시킴으로서 음성을 개선하려는 갑상연골성형술 (thyroplasty)이 성행되고 있음을 강조하고싶다. Isshiki(1974)는 이러한 thyroplasty 를 4종류로 분류하였으며 편측성 성대마비의 경우 I 형 thyroplasty (lateral compression of vocal cord) 와 IV형 thyroplasty (Lengthening of vocal cord) 가 효과적인 수술방법인데 이들 수술의 장점은 국소마취하에서 환자의 목소리를 들어가면서 lateral compression의 정도를 조정해서 시술할 수 있다는것과 갑상연골내측 연골막 밖에서 의 조작으로서 후두내 출혈이나 호흡곤란등의 위험성이 전혀 없다는 것이다. 본 교실에서는 1981 년 9월부터 1982년 3월까지 7개월간에 경험한 편측성 성대마비 7예에 대하여 국소마취하에서 thyroplasty를 시행하여 약간의 지견을 얻었기에 보고하는 바이다. 수술에 앞서서 모든 환자에게 미리 공기역학검사, 청각심리적검사, 스트로보스콥검사(stroboscopy) 및 음향분석(Sound spectrographic analysis) 을 실시하였으며 thyroplasty 시행 2 개월후에 상기한 검사를 다시 시행해서 수술전후의 음성을 비교관찰하여 다음과 같은 성적을 얻었다. 1) 공기역학검사상 최장발성지속시간 (Maximum phonation time)은 58 % 증가되었으며 이에따른 발성시호기유율 (Phonation quotient)과 평균호기유율(Mean flow rate)은 각각 58 %, 54 %로 감소되었다. 2) 청각심리적검사에서 애성의 정도가 호전되었으며 스트로보스콥검사에서도 발성시 성문간격의 개선을 보았다. 3) 음향분석도상에서 성대 진동의 주기성 (Periodicity)이 회복되었으며 특히 고주파역에서의 잡음분포가 감소되었다.

• 대순사상논총
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• 제27집
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• pp.201-243
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• 2016

창간호인 1996년 1집부터 최근 2015년 25집까지(총26집) 『대순사상논총』에 게재된 학술논문 총358편을 대상으로 연구 동향을 분석하고 발전방향을 위한 제언을 하였다. 우선, 『대순사상논총』지의 한국연구재단 등재를 위한 조건에서는 가장 중요한 학술지의 규칙성 및 정시성 등에서 자격에 미치지 못했다. 그리고 계량서지학적 분석을 보면, 학술지의 논문 수가 점차 줄어들고 있으며, 발행사항, 참고문헌 등 모든 면에서 원칙 및 규칙 등 일관성이 전혀 보이지 않았다. 그리고 최근 들어 다양한 저자가 참여하고 있지만, 공동저자 논문 비율이 너무 낮았다. 학술지의 확대를 위해서는 대순사상에 대한 전문 연구자를 확보하는 것도 중요하지만 다양한 소속기관 및 연구자들과 교류를 통해 연구 주제의 다양화를 시도하는 것이 필요하다. 『대순사상논총』의 발전을 위한 제언을 정리해보고자 한다. 첫째, 학술지 발행주기의 규칙성 및 정시성을 위해 『대순사상논총』은 연2회 발행과 12편에서 15편 정도의 논문이 게재되는 것이 좋을것 같다. 둘째, 기본적인 검색이 가능하도록 데이터베이스 구축이 이루어져야 한다. 셋째, 연구자들의 논문 공유를 위해서는 키워드와 초록은 한글과 영문으로 동시에 작성되어야 한다. 넷째, 지역적 분포도를 고려하고 다양하고 우수한 편집위원이 구성될 수 있도록 해야 한다. 다섯째, 대순사상의 특성을 주로 반영한 핵심영역과 대순사상과 융합을 할 수 있는 주변영역으로 적절이 배분되어야 한다. 여섯째, 논문의 첫 장에 중요한 서지사항이 모든 들어가는 것이 정보를 전달하는 면에서 필요하다. 일곱째, 권호 또는 Vol. no로 변환을 시도하고 발행 연월일을 명확히 해야 할 필요가 있다.

• 대한후두음성언어의학회지
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• 제14권2호
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• pp.110-116
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• 2003

Background and Objectives : Laryngeal cancer discrimination using voice signals is a non-invasive method that can carry out the examination rapidly and simply without giving discomfort to the patients. n appropriate analysis parameters and classifiers are developed, this method can be used effectively in various applications including telemedicine. This study examines voice analysis parameters used for laryngeal disease discrimination to help discriminate laryngeal diseases by voice signal analysis. The study also estimates the laryngeal cancer discrimination activity of the Gaussian mixture model (GMM) classifier based on the statistical modelling of voice analysis parameters. Materials and Methods : The Multi-dimensional voice program (MDVP) parameters, which have been widely used for the analysis of laryngeal cancer voice, sometimes fail to analyze the voice of a laryngeal cancer patient whose cycle is seriously damaged. Accordingly, it is necessary to develop a new method that enables an analysis of high reliability for the voice signals that cannot be analyzed by the MDVP. To conduct the experiments of laryngeal cancer discrimination, the authors used three types of voices collected at the Department of Otorhinorlaryngology, Pusan National University Hospital. 50 normal males voice data, 50 voices of males with benign laryngeal diseases and 105 voices of males laryngeal cancer. In addition, the experiment also included 11 voices data of males with laryngeal cancer that cannot be analyzed by the MDVP, Only monosyllabic vowel /a/ was used as voice data. Since there were only 11 voices of laryngeal cancer patients that cannot be analyzed by the MDVP, those voices were used only for discrimination. This study examined the linear predictive cepstral coefficients (LPCC) and the met-frequency cepstral coefficients (MFCC) that are the two major cepstrum analysis methods in the area of acoustic recognition. Results : The results showed that this met frequency scaling process was effective in acoustic recognition but not useful for laryngeal cancer discrimination. Accordingly, the linear frequency cepstral coefficients (LFCC) that excluded the met frequency scaling from the MFCC was introduced. The LFCC showed more excellent discrimination activity rather than the MFCC in predictability of laryngeal cancer. Conclusion : In conclusion, the parameters applied in this study could discriminate accurately even the terminal laryngeal cancer whose periodicity is disturbed. Also it is thought that future studies on various classification algorithms and parameters representing pathophysiology of vocal cords will make it possible to discriminate benign laryngeal diseases as well, in addition to laryngeal cancer.