Validations of a Numerical Model of Solute Transport in a Snowpack

이정훈,Lee, Jeonghoon The Korean Society of Economic and Environmental G 2012 자원환경지질 Vol.45 No.5

겨울철동안 쌓여 봄에 놓은 눈 녹은 물(snowmelt), 즉 융설의 유출은 북반구 및 산간지역에서 매우 중요한 것으로 여겨지고 있다. 이러한 지역에서 융설로 인한 유동 및 이온의 이동에 대한 이해는 매우 중요하며 전세계적으로 꾸준하게 연구되고 있다. Lee et al. (2008a)와 Lee et al. (2008b)연구에서는 대기로부터 수송된 이온 및 오염원이 융설에 의해 눈속을 이동하는 것을 모사하기 위한 Mobile-Immobile water Model (MIM)을 개발하였다. 이 연구에 사용된 모델을 검증하기 위해서 물질수지계산(mass balance calculation) 및 해석해(analytical solution)를 이용한 모델결과와의 비교를 수행하였다. 일정시간동안 눈 속에서의 물질의 질량변화는 눈 표면에서 들어온 물질과 눈 기저부에서 빠져나간 물질의 질량 차이와 같아야한다는 사실을 이용하여 물질수지를 계산하였다. 파면(wave front)의 이동속도 및 기존문헌에서 알려진 해석 해를 이용하여 모델결과와의 비교도 시도하였다. 모델의 물질수지계산결과 질량 차이가 거의 발생하지 않았으며 모델결과와 해석해와의 비교 역시 두 결과가 거의 일치하였다. Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

창간특집 - 언제나처럼 낙농육우농가의 든든한 대변자로 곁에 있겠습니다!

이정훈,Lee, Jeong-Hun 한국낙농육우협회 2012 낙농·육우 Vol.32 No.6

무당개구리 (Bombina orientalis) 정자의 미세구조

이정훈,권중균,Lee, Jung-Hun,Kwon, Jung-Kyun 한국현미경학회 2005 Applied microscopy Vol.35 No.4

This study described the spermatozoa of the discoglossidae Bombina orientalis using light, scanning and transmission electron microscopes. Sperm head possess a crescent or leaf shape, with a moderately flexible head, and with a sharp anterior and posterior tips. The nucleus are a thick cone shaped in the widest middle part of nucleus, and a slender anterior and posterior of nuclear tips. The chromatin is not completely compact, but irregularly imbricated such as roof. Some nuclear lacunae, irregular in shape, are scattered within the nucleus. No neck and middle piece were developed. The flagellum is composed of 9+2 axoneme, axial rod and undulating membrane. The mitochondria were distributed only in cytoplasmic membrane around the nucleus. In particular, the nuclear rod contains bundles of fibers, the rod penetrating from anterior portion to the middle of the nucleus, is extended roughly two-thirds of the nucleus such as eyelashes shaped. 본 연구는 무당개구리과 (Discoglossidae)의 무당개구리(Bombina orientalis) 정자의 형태적 특징을 광학현미경과 주사 및 투과 전자현미경으로 관찰하였다. 정자두부는 전 후방의 끝이 뾰족하고 다소 유연성을 갖는 초생달 혹은 버들 잎 모양의 특이한 구조를 취하고 있었다. 핵은 전 후방이 가늘고, 중앙 부분은 굵은 원뿔형이었다. 염색질은 완전하게 농축되어 있지 않고, 마치 널빤지를 겹쳐 놓은 듯한 지붕모양과 같은 형태로 불규칙하게 배열되어져 있었다. 핵 내에는 불규칙한 형태의 nuclear lacunae들이 흩어져 있었다. 정자경부와 중편부는 발달 되어 있지 않았다. 편모는 9+2 구조의 axoneme, axial rod 그리고 undulating membrane을 가지고 있었다. 미토콘드리아들은 핵의 상단부를 둘러싸고 있는 protoplasmic bead내에만 국한되어 존재하고 있었다. 특히, 본 연구에서 핵의 전방부에서 중앙 부위로 주행하는 nuclear rod는 섬유성 다발로 구성되었으며, 마치 사람의 속눈썹 모양과 같은 형태를 취하며, 핵의 2/3까지 뻗쳐져 있었다.

경비행기의 비행특성 분석 및 준경험적 분석 방법 비교

이정훈,Lee, Jung-hoon 항공우주시스템공학회 2022 항공우주시스템공학회지 Vol.16 No.3

In this study, for development of the MDO (Multi Disciplinary Optimization) framework, the flight dynamic characteristic parameters of the ChangGong-91, a light aircraft, were extracted by an analytical method based on various semi-empirical methods, and the flight test method was compared and evaluated. The semi-empirical analysis methods for comparative subjects were the Perkins method, McCormick method, and Smetana method. The major stability/control derivatives and dynamic factors were calculated, using each method. As the comparison criteria, the flight test derivative estimates and dynamic factors were processed, using the output error method. Additionally, the flight characteristics of the light aircraft were analyzed and evaluated according to the provisions of the Korean Airworthiness Standard (KAS) of the Ministry of Land, Infrastructure and Transport, and MIL-F-8785C for the U.S. military.

수공구조물의 적정설계를 위한 유출모형 매개변수의 민감도 분석

이정훈,김문모,여운광,Lee. Jung-Hoon,Kim. Mun-Mo,Yeo. Woon-Kwang 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

Currently, the increased run-off and the shortened arrival time are one of the causes of the city environmental disasters in urbanization. Therefore, it is necessary to properly design the hydrologic structures, but it is very difficult to forecast the values necessary to design from the planning stage. Moreover, as the parameter is changed due to the urban development, it is difficult not only to analyze the run-off influences but also to find the related studies and literatures. The purpose of this study is to utilize the results as the important basic data of the hydrologic structures, its proper design and run-off influences through the sensibility analysis of the model parameter variables. In this study, the absolute and relative sensibility analysis method were used to find out the correlation through the sensibility analysis of the topology and hydrology parameters. Especially, in this study, the changes in the run-off amount and volume were calculated according to increase/decrease in CN, the coefficient of discharge, and the empirical formula is prepared and proposed through the regressive analysis among the parameters. In the meantime, the parameter sensibility analysis was performed through the simulation HEC-HMS that is used and available in Korea. From the results of this study, it was found that the run-off amount is increased about by 10% when the CN value is increased by 5% before and after the development through the HEC-HMS simulation and data analysis. As long as there will be additional data collection analysis and result verification, and continuous further studies to find out the parameters proper to the domestic circumstances, it is expected to considerably contribute to the proper design of the hydrologic structures with respect to the ungauged basin.

Deep Trench Filling 기술을 적용한 600 V급 Super Junction Power MOSFET의 최적화 특성에 관한 연구

이정훈,정은식,강이구,Lee, Jung-Hoon,Jung, Eun-Sik,Kang, Ey-Goo 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.4

Power MOSFET(metal oxide silicon field effect transistor) operate voltage-driven devices, design to control the large power switching device for power supply, converter, motor control, etc. But on-resistance characteristics depending on the increasing breakdown voltage spikes is a problem. So 600 V planar power MOSFET compare to 1/3 low on-resistance characteristics of super junction MOSFET structure. In this paper design to 600 V planar MOSFET and super junction MOSFET, then improvement of comparative analysis breakdown voltage and resistance characteristics. As a result, super junction MOSFET improve on about 40% on-state voltage drop performance than planar MOSFET.

큰발웃수염박쥐 (Myotis macrodactylus)의 정상피세포의 분화와 미세구조

이정훈,Lee, Jung-Hun 한국현미경학회 2003 Applied microscopy Vol.33 No.1

큰발웃수염박쥐 (Myotis macrodactylus)의 세정관 정상피의 분화과정과 미세구조적 특징들은 알아보기 위하여 광학 및 전자현미경을 이용하여 조사하였다. 정자형성 과정은 4월부터 9월까지로 나타났다. 정자형성세포의 미세 구조적 특징에 있어서, A형 (Ad, Ap)의 정원세포는 기저막 위에 위치하며, Sertoli cell에 의해 둘러싸여져 있고, 대부분의 세포는 타원형이다. Ad형은 Ap형 보다 핵과 세포질의 전자밀도가 높은 것이 특징적인 반면에, B형의 정원세포는 구형의 세포로서 A형 정원세포 보다 세포가 크며, Ap형과 마찬가지로 세포질이 밝고, 거의 핵소체가 핵막에 인접되어 있다. 정모세포는 크고 구형이지만, 제 1 정모세포가 제 2 정모세포보다 다소 크다. 정자변태는 골지, 두모, 첨체, 성숙 및 이탈기로 구분하였고, 세포구조물의 특징들에 의해 각각 전 후기로 다시 세분하여 전과정을 9 (기)로 나누었다. 핵질의 변화는 골지후기부터 서서히 응축하기 시작하여, 이탈기에서 완전한 핵을 형성하였다. 정자꼬리의 형성시기는 골지전기에서 형성하기 시작하여 이탈기에서 완성되었다. 동면직전 10월부터 동면기 (11월, 12월, 이듬해 1, 2, 3월)까지는 정자형성 세포의 퇴화과정이 일어났다. 즉 미분화 정자형성 세포들은 세르톨리 세포의 식작용에 의해 포식되어졌는데 이는 동면을 위한 에너지 효율적 이용과 번식조절을 위한 적응 메카니즘이라 여겨진다. Cell differentiation and ultrastructural characteristics in the seminiferous epithelium of Myotis macrodactylus was investigated with the light and electron microscopes. Spermatogenesis has begun at April and finished at September. The nuclei of A spermatogonia (dark and pale type of spermatogonia) were oval, applied to the basal lamina, and surrounded by Sertoli cells. By comparison with other types of spermatogonia, the cell and nucleus of B type of spermatogonium is globular and larger than A types of spermatogonia. The nucleolus appears as a coarse and touches the nuclear membrane. The cell and nucleus of spermatocytes was globular and larger, but primary spematocyte is larger than secondary spermatocyte. Spermiogenesis was divided according to the level of fine structural difference, into Golgi, cap, acrosomal, maturation and spermiation phases; Golgi, cap, acrosomal and spermiation phases were further subdivided into steps of early and late phase respectively, and maturation phase has only one step. Hence, the spermiogenesis has been divided into a total of nine phases. In the change of karyoplasm, the chromatin granules are condensed at late Golgi phase and completed at spermiation phase. The sperm tail began to develop in early Golgi phase and completed in spermiation phase. The process of degeneration of spermatogenic cells in the seminiferous tubules was continually observed from October, before the beginning of hibernation, to hibernation phase (November, December, January, February, March). Immatured spermatogenic cells in the seminiferous tubules have been engulfed by phagocytosis of Sertoli cells during period of degeneration. It is deduced that the adaptative strategy serves as the mechanism to regulate the effective use of energy to prepare for long hibernation and regulation of breeding cycle.

3소자 및 4소자 위상인터페로미터 방탐시스템의 방탐모호성분석

이정훈,우종명,Lee, Jung-Hoon,Woo, Jong-Myung 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.4

In this paper, we have proposed a novel method which can analysis the direction finding ambiguity analysis for array geometry in 3 channel and 4 channel multiple baseline direction finding system. Generally, the direction finding ambiguity in the 3 element and 4 element phase interferometer direction finding system is calculated by the simulation for the array spacing or by the probability with the selected antenna array spacing. There are some restrictions to obtain the ambiguity of direction finding system in these methods. The former performs a simulation with every antenna array spacing and the latter calculates the ambiguity with the selected antenna array spacing. To overcome those restrictions, This paper proposed the novel method to calculate the ambiguity using the imaginary antenna array spacing and the phase difference prior to the modular operation in direction finder. Using the proposed method, we obtain the ambiguity probability for each of array geometry composed of multiple baseline. After performing the simulation with the selected antenna array spacing to verify the proposed method, we compared the calculated result data with the simulation data.

대륙밭쥐(Clethrionomys rufocanus) 정자의 미세구조 관찰

이정훈,Lee, Jung-Hun 한국현미경학회 2009 Applied microscopy Vol.39 No.2

Cricetinae 아과 Clethrionomys 아속에 속하는 한국산 대륙밭쥐(Clethrionomys rufocanus)의 정자의 형태적 특징을 알아보기 위하여 주사 및 투과형전자현미경으로 관찰하였다. C. rufocanus정자머리의 모양은 날카롭게 굽은 하나의 dorsal hook를 가지며, 전체적인 머리모양은 마치 도끼모양의 형태를 취하고 있었다. C. rufocanus정자의 전체길이는 95.8 ${\mu}m$이었으며, 정자머리의 길이는 7.8 ${\mu}m$, 꼬리는 88.0 ${\mu}m$이었다. 꼬리는 경부 (1.0 ${\mu}m$), 중편부(22.0 ${\mu}m$), 주편부와 미부 (65.0 ${\mu}m$)로 각각 구성되어져 있었다. 분절주 (segmented columns)는 약 10~12개의 마디로 이루어져 있었으며, 미토콘드리아의 수는 약 170~178개 정도이었다. 첨체 후 덮개는 핵의 1/2을 점유하고 있었으며, 적도절은 핵 표면의 첨체 후 덮개(post-nuclear cap)와 첨체덮개(acrosomal cap) 사이에 위치하고 있었다. 1, 5, 6번의 외측섬유들은 다른 것보다 더 크며, 섬유초 (fibrous sheath)와 종 지주(longitudinal column)은 주편부에서 관찰되어졌으며, 미부에서는 섬유초가 존재하지 않았다. 이상의 결과로 미루어 보아, 정자두부와 꼬리의 형태적인 구조는 정자의 진화 패턴과 종을 분류하는데 유용한 정보를 제공하리라 여겨진다. To investigate the morphological characteristics of spermatozoa of the grey red-blacked vole (Clethrionomys rufocanus) belongings to the subfamily Cricetinae, subgenus Clethrionomys were examined by scanning and transmission electron microscopes. The sperm head of C. rufocanus was an ax or hatchet in shape with a curved single dorsal hook. The total length of C. regulus sperm was 95.8 ${\mu}m$. The length of sperm head was 7.8 ${\mu}m$, and the tail (88.0 ${\mu}m$) consisted of four major segments: the neck (1.0 ${\mu}m$), middle piece (22.0 ${\mu}m$), and principal piece plus end piece (65.0 ${\mu}m$), respectively. The segmented columns were about 10~12 in number. The number of gyres of mitochondria ranged from about 170 to 178. The post-nuclear cap occupied about a half of nucleus. The equatorial segment is located between the post-nuclear cap segment and acrosomal cap on the nuclear surface. Nos. 1, 5 and 6 of the outer dense fibers were larger than the others. A fibrous sheath and longitudinal column of the principal piece were in evidence, but the fibrous sheath was not seen at the end piece. In conclusion, the morphological structures of sperm head and tail may be useful information to patterning of sperm evolution and classifying of species.

낙농인 교육 - 친환경정책과 농축산업 인식이 빚어낸 유럽 낙농산업

이정훈,Lee, Jeong-Hun 한국낙농육우협회 2017 낙농·육우 Vol.37 No.2