• International journal of advanced smart convergence
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• 제10권4호
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• pp.241-255
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• 2021

The human auricle is the first part to receive sound from the outside. In this part, the frequency range of human recognizable form is divided and organized. In this study, we propose modeling by applying a single sound source to the surface of the human auricle. This means that when the sound pressure of a low frequency (low frequency) sound enters the pinna, the impedance felt at the tip of a part of the non-linear surface of the pinna is mainly due to the tensile force at the end of the part of the non-linear surface of the pinna. By expressing the situation of moving at a very small speed, the characteristic impedance of the pinna was confirmed to be negative infinity, and it was also confirmed that the speed at the tip of a part of the non-linear surface of the pinna was 0 in the anti-resonance state. It was found that the wave propagation phenomenon that determines the characteristics of the filter is determined by how large the wavelength, kL, is compared to the length of the tip of a part of the non-straight surface of the pinna. Humans first receive sounds from outside through their ears. The auricle is non-linear and has a curved shape, and it is known that it analyzes frequencies while receiving external sounds. The human ear has an audible frequency range of 20Hz - 20,000Hz. Through the study, we applied the characteristics of the notch filter to hypothesize that the human audible frequency range is separated from the auricle, and applied filter theory to analyze it, and as a result, meaningful results were obtained. The curved part and the inner part of the auricle function as a trumpet, collecting sounds, and at the same time amplifying the weak sound of a specific band. The point was found and the shape of the envelope detected in the auricle was found. Selectivity for selecting sounds coming from the outside is the formula of the pinna that implements the function of Q. The function of distinguishing human-recognizable sound from the pinna from low to high through frequency analysis is performed in the pinna, and the 2-3kHz area, where human hearing threshold is the most sensitive, is also the acoustic impedance of the most recessed area of the pinna. It can be seen that starting from.

• Molecules and Cells
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• 제40권4호
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• pp.271-279
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• 2017

Ran-binding protein family member, RanBP9 has been reported in various basic cellular mechanisms and neuropathological conditions including schizophrenia. Previous studies have reported that RanBP9 is highly expressed in the mammalian brain and retina; however, the role of RanBP9 in retinal development is largely unknown. Here, we present the novel and regulatory roles of RanBP9 in retinal development of a vertebrate animal model, zebrafish. Zebrafish embryos exhibited abundant expression of ranbp9 in developing brain tissues as well as in the developing retina. Yeast two-hybrid screening demonstrated the interaction of RanBP9 with Mind bomb, a component of Notch signaling involved in both neurogenesis and neural disease autism. The interaction is further substantiated by co-localization studies in cultured cells. Knockdown of ranbp9 resulted in retinal dysplasia with defective proliferation of retinal cells, downregulation of neuronal differentiation marker huC, elevation of neural proliferation marker her4, and alteration of cell cycle marker p57kip2. Expression of the $M{\ddot{u}}ller$ glial cell marker glutamine synthase was also affected in knockdown morphants. Our results suggest that Mind bomb-binding partner RanBP9 plays a role during retinal cell development of zebrafish embryogenesis.

• Clinical and Experimental Pediatrics
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• 제49권5호
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• pp.519-522
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• 2006

목 적 : Alagille 증후군은 간, 심장, 눈, 척추, 얼굴 모양 등 여러 장기에 이상을 일으키며 상염색체 우성으로 유전되는 질환이다. Alagille 증후군의 유전자인 JAG1은 Notch 수용체에 대한 리간드를 만든다. 이 연구의 목적은 우리나라 Alagille 증후군 환자에서 JAG1 유전자의 돌연변이를 찾아내는 것이다. 방 법 : Alagille 증후군으로 확진 받은 6명의 말초혈액 백혈구에서 DNA를 추출하여 JAG1 유전자에 대하여 중합효소연쇄 반응 및 정제 후 직접 염기서열 분석하였다. 결 과 : 2개의 새로운 frameshift 돌연변이가 발견되었다. 4세에 간세포암이 발생한 환자에서 엑손 2에서 118delC이 발견되었다. 한 환자에서는 엑손 7에서 999-1000delTG이 발견되었는데, 2개 돌연변이들은 정지코돈을 만들었다. 결 론 : 우리나라 Alagille 증후군 환자에서 단백이 잘라져 기능을 못하는 frameshift 돌연변이를 찾아내었다.

• 한국가스학회지
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• 제16권4호
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• pp.16-22
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• 2012

용접기술의 발달과 더불어 기계, 교량, 선박 그리고 가스설비 등의 제작공정을 위하여 용접의 이용이 증가하고 있다. 따라서 그들의 용접 구조물 제작을 위하여 높은 생산성과 안전설계를 고려하는 용접 법을 개발하는 것이 요구되고 있다. 본 연구에서는 재료 두께, 용접층수, 하중 방향 그리고 토우부의 노치 반경과 관련하여 완전 용입 십자형 필릿 용접부의 피로강도 및 피로수명의 특성에 대하여 기초적으로 고찰하였다. 대부분의 피로파괴는 십자형 필릿 용접의 토우부에서 발생하였다. 피로강도 및 피로수명은 토우 부의 노치 반경과 플랭크 각에 의한 응력집중의 영향을 받고 있다. 토우부의 금속이 다층 용접에 의하여 어닐링 되고 확산 되었으며 그 결과 침상 페라이트 조직이 형성되어 피로강도와 피로수명을 향상시켰다.

• Smart Structures and Systems
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• 제4권3호
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• pp.343-365
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• 2008

In this study, the frequency domain method which utilizes the evaluation of changes in the structural mode shape is adopted to identify regions which contain localized damages. Frequency response function (FRF) values corresponding to the modal frequency, analogous to the mode shape coefficients, are used since change in natural frequency of the system is usually insignificant for localized damage. This method requires only few sensors to obtain the dynamic response of the structure at specific locations to determine the FRF via fast-Fourier transform (FFT). Numerical examples of an aluminum plate, which includes damages of varying severity, locations and combinations of multiple locations, are presented to demonstrate the feasibility of the method. An experimental verification of the method is also done using an aluminum plate with two different degrees of damage, namely a half-through notch and a through notch. The inconsistency in attaining the FRF values for practical applications due to varying impact load may be overcome via statistical averaging, although large variations in the loading in terms of the contact duration should still be avoided. Nonetheless, this method needs special attention when the damages induce notable changes in the modal frequency, such as when the damages are of high severity or cover more extensive area or near the boundary where the support condition is modified. This is largely due to the significant decrease in the frequency term compared to the increase in the vibration amplitude. For practical reasons such as the use of limited number of sensors and to facilitate automation, extending the resolution of this method of identification may not be efficient. Hence, methods based on wave propagation can be employed as a complement on the isolated region to provide an accurate localization as well as to trace the geometry of the damage.

• Nuclear Engineering and Technology
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• 제35권6호
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• pp.529-536
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• 2003

The objective of this study is to investigate the reorientation of hydrides with applied stress intensity factor, the peak temperature and the time when to apply the stress intensity factor in a Zr-2.5Nb pressure tube during its thermal cycle treatment. Cantilever beam (CB) specimens with a notch of 0.5 mm in depth made from the Zr-2.5Nb tube were subjected to electrolytic hydrogen charging to contain 60 ppm H and then to a thermal cycle involving heating to the peak temperature of either 310 or $380^{\circ}C$, holding there for 50 h and then cooling to the test temperature of $250^{\circ}C$. The stress intensity factor of either 6.13 or $18.4\;MPa\sqrt{m}$ was applied at the beginning of the thermal cycle, at the end of the hold at the peak temperatures and after cooling to the test temperature, respectively. The reorientation of hydrides in the Zr-2.5Nb tube was enhanced with the increased peak temperature and applied stress intensity factor. Furthermore, when the CB specimens were subjected to $18.4\;MPa\sqrt{m}$ from the beginning of the thermal cycle, the reoriented hydrides occurred almost all over the Zr-2.5Nb tube, surprisingly suppressing the growth of a DHC crack. In contrast, when the CB specimens were subjected to the stress intensity factor at the test temperature, little reorientation of hydrides was observed except the notch region, leading the Zr-2.5Nb to grow a large DHC crack. Based on the correlation between the reorientation of hydrides and the DHC crack growth, a governing factor for DHC is discussed along with the feasibility of the Kim's DHC model.

• 한국자원식물학회지
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• 제19권2호
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• pp.360-364
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• 2006

도깨비고비와 참쇠고비의 포자발아에서 얻은 전엽체를 균질화하여 배양함으로써 전엽체 개체발생과 포자체 형성과정을 연구하였다. 배양 2주일이 지나자 균질화한 전엽체 세포들이 일차원의 필라멘트 형태를 형성하였고, 4주일째에는 다수의 가지를 뻗은 형태의 전엽체가 출현하였다. 배양 6주일째에 apical notch가 발달된 전엽체가 형성되었는데. 중심부에는 분열조직이 발달되었다. 8주의 배양기간이 지나자 전엽체의 중심부에서 장란기의 형성 없이 무수정생식에 의한 bud가 관찰되었다. 10주일이 지나자 무수정생식에 의한 bud는 포자체로 발달되었는데, flow cytometric 분석 결과 도깨비고비와 참쇠고비 모두에서 전엽체와 포자체는 동일한 ploidy level을 지닌 것으로 확인되었다. 이는 도깨비고비뿐만 아니라 참쇠고비 또한 무수정생식을 하는 양치식물임을 증명하는 결과로 생각된다.

• 한국전자파학회논문지
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• 제17권12호
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• pp.1199-1205
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• 2006

본 논문은 두 개의 대역 저지 반파장 슬롯을 방사체에 삽입하여, 향상된 대역 저지 특성을 갖는 보우타이형 광대역 모노폴 안테나를 제안하였다. 제안된 안테나는 전자기적으로 급전된 보우타이 형태의 방사 평면과 접지면 사이에 반원 모양의 기생 접지면을 추가한 구조이다. 향상된 대역 저지 특성을 얻기 위하여 두 수평 슬롯간의 결합량을 조절하였다. 측정된 안테나는 $4.96{\sim}5.51GHz$에서 저지 특성을 갖고, $2.7{\sim}6.9GHz$에서 정재파비 2.0 이하를 만족하는 광대역 특성을 나타내었다. 단일 슬롯 사용과 비교하면, 넓은 저지 대역폭과 향상된 스커트 특성을 나타내었다. 측정된 안테나의 방사 패턴은 이상적인 모노폴 안테나와 유사한 특성을 가지며, 저지 대역에서의 안테나 이득은 다른 동작 주파수에 비해 x-z 평면을 기준으로 $5{\sim}10dB$ 이상 감소되었다.

• 치과방사선
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• 제14권1호
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• pp.99-107
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• 1984

The auther studied clinically and. radiologically 48 cases which had been diagnosed as TMJ ankylosis in SNUDH (1974-1984). The purpose of this study is to analyse clinical features of TMJ ankylosis and to evaluate the effect of TMJ ankylosis on the growth of the mandible. The obtained results were as follows: 1. Total 48 cases of TMJ ankylosis patients consist of 23 males and 25 females. 65 percent of all cases of TMJ ankylosis occurred in patients between 1 and 10 years of age. The awerage age at the onset of ankylosis was 11.7 and average duration at the time of examination was 11.7 years. 2. Unilateral akylosis (81.3%) was more frequent than bilateral ankylosis (18.7%). 3. Traum a (57.9%) and infection (21.2%) were main etiology. 4. Inability to open the mouth (78.3%) and facial asymmetry (17.4%) were main chief complaints. 5. Mandibular morphology through radiographic features. (a) In TMJ ankylosis patients the ramus length of the ankylosed side was shorter than that of the non-ankylosed side. Comparing with the centrol group, ramus length of the each side was shorter than normal value. (b) The partial body length of the ankylosed side was longer than that of the non-ankylosed side. Comparing with the control group, partial body length of the each side was longer than normal value. Partial body length was related with antegonial notch depth. (c) Ratio of upper and lower ramus length at the level of mandibular foramen was smaller in ankylosed side than in non-ankylosed side. (d) Antegonial notch depth and ramus posterior contour depth were deeper in ankylosed side than in non-ankylosed side and those of both sides were deeper than normal value. (e) Gonial angle in ankylosed side was larger than in non-ankylosed side and that in both sides was smaller than normal value.

• 대한기계학회논문집
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• 제12권6호
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• pp.1327-1334
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• 1988

본 연구에서는 회전굽힘응력하에서 비관통노치를 갖는 재료의 피로거동을 분 석하기 위하여 우선 시험편의 반지름에 해당한 심공노치를 갖는 시험편을 준비하고 이 시험편이 고, 중간, 저응력을 받는경우 작용응력의 대소에 의한 표면 및 내부크랙전파 특성과 함께 크랙면형상변화 관계를 검토하였다.