• Journal of Plant Biology
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• v.37 no.3
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• pp.317-323
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• 1994

The calluses formed on the surface of a quarter-girdled Robinia pseudoacacia stems have been shown to originate from immature xylem cells and preexisting cambial cells. The cellus is not only formed by periclinal and anticlinal divisions of radial cells, but also axial cells. In tangential view, the callus at initial stage showed heterogeneous structure composed of long and short cells and then homogeneous one with short cells. Some cells of homogeneous structure in middle region of callus at early stage is later elongated and others mainly divided in trasverse plane. In the result the homogeneous structure becomes into a heterogeneous one. Subsequently, the long cells in heterogeneous structures elongated further and became fusifrom initials, and the short cells divided transversely became ray initials. The appearence of homogeneous and heterogeneous structure in the callus on debarked stem without organ elongation is almost similar to that of the structure in the procambium of young stem which is elongating extensively. Eventually, the ontogeny of vascular cambium in wound callus resembles that of a young stem grown normally, although the debarked stem does not grow in length but in girth and the young stem elongates activity. These findings mean that the active intrusive growth of short procambial cells occurs during the differentiation of fusiform cambial cells.

• Journal of Plant Biology
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• v.35 no.3
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• pp.273-281
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• 1992

The origin of the interfascicular cambium from residual meristem can be elucidated by tangential and transverse observation. It is clear that there is structural distinction between interprocambial and interfascicular residual meristem and adjacent parenchyma in both the transverse and tangential view. Consequently, the residual meristem does not convert into parenchyma but, rather, becomes interfascicular cambium. In tangential view, the homogeneous structure of interfascicular residual meristem at an early stage changes gradually into a heterogeneous one at a later stage, with long and short cells from which fusiform and ray initials originate respectively. However, the homogeneous structure of parenchyma adjacent interfascicular residual meristem does not change into a heterogeneous one but remains the same at all stages of development. Therefore, the interfascicular cambium has a direct ontogenetic continuity with the residual meristem, and does not have its secondary origin from differentiated parenchyma. Furthermore, the ontogenetic pattern of the interfascicular cambium is almost the same as that of fascicular cambium.ambium.

• Journal of Plant Biology
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• v.36 no.3
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• pp.275-279
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• 1993

The early ontogeny of the vascular cambium in the hypocotyl of Eucommia ulmoides seedling was studied anatomically. In transverse view, the procambial cells repeated periclinal divisions and then gradually differentiated into vascular cambium; however, in the transectional plane, it was difficult to reveal the origin of cambial initials. In tangential view, the early procambial cells repeated periclinal divisions and then the procambium consisted of homogeneous short cells. Some cells in late procambium did not show transverse divisions, but elongated continuously. Thus, the procambium showed a heterogeneous structure: The long cells became fusiform initials with tapering end walls and the short cells differentiated into ray initials. Conclusively, the two types of cambial initials were gradually originated from the homogeneous cells at the early procambial stage, and they consisted vascular cambium.

• Journal of the Korean Mathematical Society
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• v.42 no.6
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• pp.1311-1322
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• 2005

We consider the several plane sector domains which are bonded together along common edges with vertex at the origin. Such domains appear in electric conducting problem with multi-layered heterogeneous media. Our aim is to give a structure theorem of the singularities of the electric field at the corner. Also, we provide a regularity theorem for the electric field.

• Advances in Computational Design
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• v.3 no.2
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• pp.147-163
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• 2018

Cementitious composites are multiphase heterogeneous materials with distinct dissimilarity in strength under compression and tension (high under compression and very low under tension). At macro scale, the phenomenon can be well-explained as the material contains physical heterogeneity and pores. But, it is interesting to note that this dissimilarity initiates at molecular level where there is no heterogeneity. In this regard, molecular dynamics based computational investigations are carried out on cement clinkers and calcium silicate hydrate (C-S-H) under tension and compression to trace out the origin of dissimilarity. In the study, effect of strain rate, size of computational volume and presence of un-structured atoms on the obtained response is also investigated. It is identified that certain type of molecular interactions and the molecular structural parameters are responsible for causing the dissimilarity in behavior. Hence, the judiciously modified or tailored molecular structure would not only be able to reduce the extent of dissimilarity, it would also be capable of incorporating the desired properties in heterogeneous composites. The findings of this study would facilitate to take step to scientifically alter the structure of cementitious composites to attain the desired mechanical properties.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.10
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• pp.1237-1247
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• 1999

이질적 분산 환경에서 전자 상거래는 신임장을 기반으로 상거래 참여자들에 대한 인증 서비스가 제공되어야 한다. 본 연구에서는 CORBA 보안 명세 1 를 기반으로 전자 상거래 참여자들에 대한 객체 단위 인증 및 권한 부여 기법을 제공하는 상호 인증 서비스 구조를 제안한다. 이 구조는 Kerberos 2 의 인증 기법 및 인증 키 교환 기법으로 전자 상거래 참여자간에 상대 주체의 신원 확인 뿐 아니라 거래 진행 중 취득한 정보의 근원을 파악할 수 있도록 하였다. 또한 Kerberos 기법을 CORBA 플랫폼 기반의 상호 인증 구조로서 분산 환경에 대해 확장하였으므로 키 관리 등 보안 정보 관리에 있어 효율적이다.Abstract Electronic commerce shall provide its subjects with a credential-based authentication service in the heterogeneous distributed computing environment. In this paper, based on CORBA security service specification 1 which OMG defined, we propose the mutual authentication service for subjects of electronic commerce, providing the authentication of object level and the authenticated key exchange. This proposed structure, by Kerberos 2 for the authentication and the authenticated key exchange, assures not only the identification of a partner but also the confidence of origin of business item for negotiations between subjects of electronic commerce. Since our deployed Kerberos is extended to the mutual authentication service based on CORBA platform, it is efficient for security administration to manage the information such as a key management in the heterogeneous distributed computing environment.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.333-342
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• 2018

Intracranial germ cell tumors (iGCTs) are a heterogeneous group of tumors with peculiar characteristics clearly distinguished from other brain tumors of neuroepithelial origin. Diverse histology, similarity to gonadal GCT, predilection to one sex, and geographic difference in incidence all present enigmas and fascinating challenges. The treatment of iGCT has advanced for germinoma to date; thus, clinical attention has shifted from survival to long-term quality of life. However, for non-germinomatous GCT, current protocols provide only modest improvement and more innovative therapies are needed. Recently, next-generation sequencing studies have revealed the genomic landscape of iGCT. Novel mutations in the KIT-RAS-MAPK and AKT-MTOR pathways were identified. More importantly, methylation profiling revealed a new method to assess the pathogenesis of iGCT. Molecular research will unleash new knowledge on the origin of iGCT and solve the many mysteries that have lingered on this peculiar neoplasm for a long time.

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.259-263
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• 2003

This study was carried out to get basic information about the morphological and production characteristics of fennel populations different origin under different ecological conditions in Hungary. The Korean population can be registered as a medium high genotype and showed a more accelerated growth characters than Hungarian taxon and the two populations have a medium homogeneity $(CV\;=\;4{\sim}22%)$. In the second year plant height in Hungarian taxon was significantly higher than that of the Korean population. The shooting dynamic of individual plants might be heterogeneous in both taxa and the Korean population was not only shorter in the height but had also less shoots by 16% than the Hungarian one. The Hungarian taxon exceeded the umbel size and numbers to the Korean one (by 3.62 cm in the average) and the variability in the populations was high $(CV\;=\;29{\sim}49%)$. Seed size was proved to be also a discriminative feature between the examined taxa. With small deviations (CV < 2) the Hungarian population produced seeds longer by 38%. Homogeneity in the populations was dependent more on the vegetation years and on the characteristics measured but less on the origins, respectively.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.152-157
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• 1994

Inulinase of Kluyveromyces marxianus origin was produced by recombinant yeast Saccharomyces cerevisiae under the control of GAL1 promoter, to examine the expression and localization of inulinase in a repressed(galactose-free) or derepressed(galactose-containinga) medium. The inulinase gene(INU1A) was constitutively expressed at 6.7 units/ml in a repressed medium. When the cell started to utilize galactose in a derepressed medium, the INU1A gene began to be expressed, and the final expression level reached about 45 units/ml. According to be the nondenaturingPAGE analysis, inulinase produced by S. cerevisiae was found to be less glycosylated than the bakers yeast invertase. In addition, its glycosylation pattern was less heterogeneous than the K. marxianus inulinase. The supplementation of inulin or raffinose into the derepressed medium increased the cell growth rate, while the expression of INU1A was repressed. Regardless of the carbon sources examined, most of inulinase activity (more than 98%) was found in the extracellular medium, indicating excellent secretion efficiency.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.55.2-55.2
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• 2014

Role of environments is one of today's most widely discussed and debated topic in the field of extra-galactic astronomy. Extreme morphology-density relations found in low-mass galaxies are considered to be the result of an effective role played by environment in the evolution of these galaxies. I will present the results from our dedicated study of early-type dwarf galaxies (dEs) in different environments using imaging and spectroscopic data. We find that Virgo cluster dEs have a variety of structural and kinematic properties. A significant fraction of dEs possesses disk features, such as spiral arm and bar, while a central nucleus seems to be universal in these low mass galaxies. We also find that a majority of dEs are fast rotator and their rotation curves are much steeper than that of spiral galaxies of similar mass. Finally I will discuss how the different environmental mechanisms, i.e., gas-stripping or tidal interaction, can contribute to form heterogeneous dEs in Virgo cluster.