• Title/Summary/Keyword: DH

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Physical Properties of Octahedral Iron (Ⅱ) Complexes of Vicinal-Dioximes (팔면체형 철 (Ⅱ) Vicinal-디옥심 착물의 물리적 성질)

  • Chong-Shik Chin;L. Vaska
    • Journal of the Korean Chemical Society
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    • v.24 no.5
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    • pp.380-392
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    • 1980
  • Six coordinate low spin iron(Ⅱ) complexes of vicinal-dioximes, [Fe$(DH)_2B_2$] and [Fe$(DH)_2$B(CO)]($(DH)_2$=$(CHDH)_2$(bis(1,2-cyclohexadinedioximato) bivalent anion), $(DPGH)_2$-(bis(diphenylglyoximato) bivalent anion), $(F{\alpha}DH)_2(bis(furil-{\alpha}-dioximato)$ bivalent anion); B = monodentate neutral nitrogen base), have been prepared and their physical properties have been investigated with respect to the effects of the equatorial ligands, $(DH)_2$. The order of ${\pi}$-acceptor CO stretching frequency for [Fe$(DH)_2$B(CO)] is $(F{\alpha}DH)_2$ > $(DPGH)_2$> $(CHDH)_2$, while non-${\pi}$-acceptor $NH_3$ stretching frequencies for [Fe$(DH)_2(NH_3)_2$] show the opposite order to that of CO, i.e., $(CHDH)_2$ > $(DPGH)_2$ > $(F{\alpha}DH)_2$. These infrared spectral data together with Fe-N (oxime) and Fe-N (oxime) and Fe-N (B) stretching frequency data suggest that the nitrogen atoms of $(CHDH)_2$ are more basic and poorer ${\pi}$-acceptors than the corresponding nitrogen atoms of $(DPGH)_2$ and $(F{\alpha}DH)_2$, respectively. It has been found from the electronic spectral data of [Fe$(DH)_2$] and [Fe$(DH)_2$B(CO)] that the energy of the charge transfer band from iron(Ⅱ) to $(DH)_2$ increases as the basicity of $(DH)_2$ increases.

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Analysis and Comparison of Standard and Existed Heating Degree-Hours Model for decision of Greenhouse Heating Load in Korea (온실의 난방부하 결정을 위한 Degree-Hour 모델식 비교 분석)

  • Woo, Young-Hoe
    • Journal of Practical Agriculture & Fisheries Research
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    • v.6 no.1
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    • pp.143-154
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    • 2004
  • The value of daily heating degree hour(described as DH hereafter) is essential for calculating the heating load of a greenhouse during the winter months. Many researchers have so for proposed different models for estimating DH value. Models for estimating DH have been investigated DH(unit, ℃·h·year-1) in this paper. The comparisons of standard and existed DH values were made to know the estimation error of each model proposed so far. The standard DH values and other proposed DH values have were obtained for the inside setpoint temperatures of 9, 13, 16 and 20℃ in greenhouse, estimated based on meterological data from 1961 to 2000 according to locals, and standard DH values were independent and existed DH values were dependent. Among the various model, the one developed theoretically by Mihara modified to author was the best fitting for standard DH values. The DH values were obtained for the inside setpoint temperature of 9, 13, 16 and 20℃ by Modified Mihara's model. A new DH contour line graph was proposed using Modified Mihara's model. Using the DH contour line graph, the DH values can be obtained easily for any setpoint according to local.

Experiment and Nonlinear Analysis of DH Beams with Steel Form (외부철판이 사용된 DH Beam의 휨거동에 대한 실험 및 비선형해석)

  • Moon, Jeong-Ho;Oh, Young-Hun
    • Journal of the Korea Concrete Institute
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    • v.26 no.2
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    • pp.171-179
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    • 2014
  • The purpose of this study is to evaluate the structural performance of DH beams. DH beam construction method uses thin steel plates as form-works and structural elements. The prefabricated plates and rebars of DH beams were transported to a construction site and erected for casting concrete at the site. In this study, the contribution of steel plates to the flexural strength was evaluated since the plates were expected to play a role as reinforcements. Five test specimens were made for experimental and analytical studies. They consisted of two DH beams for the positive moment test and two DH beams for the negative moment test and a RC beam for the comparison purpose. Test results on DH beams were compared with design equations and the RC beam test result. It was proven that DH beams demonstrated the good flexural behavior showing sufficient strengths and deformation capacities. Flexural strengths, principal strains of concrete, and rebar stresses were evaluated through nonlinear finite element analyses for two test beams. The analyses also showed that steel plates can contribute to the enhancement of flexural strength of DH beams. Based on experimental and analytical studies, it was concluded that steel plates of DH beams can be used as good flexural reinforcements.

Composite Behavior and Shear Strength of DH-Beams with Steel Deck Plates (무해체 데크플레이트 철판을 사용한 DH-beam의 합성거동과 전단강도)

  • Moon, Jeong-Ho;Oh, Young-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.3
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    • pp.1-9
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    • 2016
  • The purpose of this study is to examine the shear strength and structural performance of DH-Beams. The DH-Beam construction method uses thin steel plates as form-works and structural elements. Steel plates and rebars for DH-Beams were prefabricated at factory and then erected before casting concrete at construction sites. In this study, the contribution of steel plates to the shear strength of DH-Beam was evaluated since the plates were expected to work as reinforcements. Five test specimens were made for experimental and analytical studies. They consisted of two DH-Beams for the positive loading test and two DH-Beams for the negative loading test and a RC beam for the comparison purpose. Test results on DH-Beams were compared with design equations and the RC beam test result. It was proven that DH-Beams demonstrated the good shear behavior showing sufficient strengths and deformation capacities. Nonlinear analyses with test specimens were also used to evaluate the contribution of DH plates to strengths. Analytical models included various cases such as beams with lateral plates only or beams without any plates. These analyses also showed that steel plates can contribute to the enhancement of shear strength of DH-Beams. Based on experimental and analytical studies, it was concluded that steel plates of DH-Beams can be used as good shear reinforcements.

A Universal Method for Constructing DH parameters from Unified Robot Description Format (URDF로부터 DH 파라미터를 구성하는 일반적인 방법)

  • Byeonggi Yu;Junyoung Lee;Sang hyun Park;Maolin Jin
    • The Journal of Korea Robotics Society
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    • v.18 no.1
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    • pp.37-47
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    • 2023
  • This paper introduced how to construct Denavit-Hartenberg (DH) parameters from the Unified Robot Description Format (URDF). URDF is convenient for describing a robot even though the robot is very complex. On the other hand, DH convention is not an easy notation for many novices who want to describe a robot. Therefore, most vendors provide URDF and users prefer to use URDF to describe a robot. However, some controllers or algorithms are based on DH parameters to perform kinematics, dynamics, control, etc. To connect URDF and DH parameters, we present a three-step approach to construct DH parameters from URDF. The first step is to define the joint axis for constructing DH parameters. The second step is constructing DH parameters to define joint character. The final step is constructing DH parameters to define the coordinate frame of the child link. This approach is based on intuitive vector calculation and guarantees the uniqueness of DH parameters. To verify our approach, we applied our approach to a simple one-link robot, a manipulator with 6 DOF, and a quadruped robot with 3 DOF per leg. We verified that our approach worked well based on forward kinematic results.

A Study on Digital Humanities Research Guides of Academic Libraries in the U.S. (대학도서관의 디지털 인문학 연구지원 가이드에 관한 연구 - 미국 대학도서관 사례를 중심으로 -)

  • Lee, Jisu
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.1
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    • pp.297-320
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    • 2022
  • In this study, the current status of digital humanities(DH) research support guide service, which is increasing recently in research-oriented academic libraries in the United States, was analyzed by comparing the contents provided by each institution's Website. Based on the ranking of research-focused academic libraries with the largest volume of books in North America as of 2018-19 in Association of Research Libraries(ARL) statistics, the service contents of 30 institutions providing DH research support guide service were analyzed. The criteria for analysis are 8 components of services presented in previous studies: (1) tools and technology, (2) funding, (3) community, (4) pedagogy, (5) projects, (6) resources, (7) publications and consultations, and (8) workshops and training. As a result of the analysis, it was found that most of the institutions operating the DH research support guide service provided 'DH resources', and more than half of the institutions were providing 'DH tools and technology' and 'DH community' information. In addition, most institutions are operating the DH research support guide service in cooperation with the library itself, on-campus research institutes and centers, or other departments for DH publication and project consultation, so they focused on research support information services through consulting. In the future, discussions on the DH research support guide service operation plan of domestic academic libraries and the competency of service personnel should be continued.

Anchorage Effects of Various Steel Fibre Architectures for Concrete Reinforcement

  • Abdallah, Sadoon;Fan, Mizi;Zhou, Xiangming;Geyt, Simon Le
    • International Journal of Concrete Structures and Materials
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    • v.10 no.3
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    • pp.325-335
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    • 2016
  • This paper studies the effects of steel fibre geometry and architecture on the cracking behaviour of steel fibre reinforced concrete (SFRC), with the reinforcements being four types, namely 5DH ($Dramix^{(R)}$ hooked-end), 4DH, 3DH-60 and 3DH-35, of various hooked-end steel fibres at the fibre dosage of 40 and $80kg/m^3$. The test results show that the addition of steel fibres have little effect on the workability and compressive strength of SFRC, but the ultimate tensile loads, post-cracking behaviour, residual strength and the fracture energy of SFRC are closely related to the shapes of fibres which all increased with increasing fibre content. Results also revealed that the residual tensile strength is significantly influenced by the anchorage strength rather than the number of the fibres counted on the fracture surface. The 5DH steel fibre reinforced concretes have behaved in a manner of multiple crackings and more ductile compared to 3DH and 4DH ones, and the end-hooks of 4DH and 5DH fibres partially deformed in steel fibre reinforced self-compacting concrete (SFR-SCC). In practice, 5DH fibres should be used for reinforcing high or ultra-high performance matrixes to fully utilize their high mechanical anchorage.

The role of diuretic hormones (DHs) and their receptors in Drosophila

  • Gahbien Lee;Heejin Jang;Yangkyun Oh
    • BMB Reports
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    • v.56 no.4
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    • pp.209-215
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    • 2023
  • Maintaining internal homeostasis and regulating innate behaviors are essential for animal survival. In various animal species, a highly conserved neuroendocrine system integrates sensory inputs and regulates physiological responses to environmental and internal changes. Diuretic hormones 44 and 31, which are homologs of mammalian corticotropin-releasing factor (CRF) and calcitonin gene-related peptide (CGRP), respectively, control body fluid secretion in Drosophila. These neuropeptides and their receptors have multiple physiological roles, including the regulation of body-fluid secretion, sleep:wake cycle, internal nutrient-sensing, and CO2-dependent response. This review discusses the physiological and behavioral roles of DH44 and DH31 signaling pathways, consisting of neuroendocrine cells that secrete DH44 or DH31 peptides and their receptor-expressing organs. Further research is needed to understand the regulatory mechanisms of the behavioral processes mediated by these neuroendocrine systems.

Data Hiding Using Sequential Hamming + k with m Overlapped Pixels

  • Kim, Cheonshik;Shin, Dongkyoo;Yang, Ching-Nung;Chen, Yi-Cheng;Wu, Song-Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.12
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    • pp.6159-6174
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    • 2019
  • Recently, Kim et al. introduced the Hamming + k with m overlapped pixels data hiding (Hk_mDH) based on matrix encoding. The embedding rate (ER) of this method is 0.54, which is better than Hamming code HC (n, n - k) and HC (n, n - k) +1 DH (H1DH), but not enough. Hamming code data hiding (HDH) is using a covering function COV(1, n = 2k -1, k) and H1DH has a better embedding efficiency, when compared with HDH. The demerit of this method is that they do not exploit their space of pixels enough to increase ER. In this paper, we increase ER using sequential Hk_mDH (SHk_mDH ) through fully exploiting every pixel in a cover image. In SHk_mDH, a collision maybe happens when the position of two pixels within overlapped two blocks is the same. To solve the collision problem, in this paper, we have devised that the number of modification does not exceed 2 bits even if a collision occurs by using OPAP and LSB. Theoretical estimations of the average mean square error (AMSE) for these schemes demonstrate the advantage of our SHk_mDH scheme. Experimental results show that the proposed method is superior to previous schemes.

Diapause hormone of the silkworm, Bombyx mori : Structure and function

  • Okitsugu Yamashita
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 1997.06a
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    • pp.51-72
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    • 1997
  • Diapause hormone (DH) is a neuropeptide hormone which is secreted from the suboesophageal ganglion (SG) and is responsible for induction of embryonic diapause of the silkworm, Bombyx mori. DH is isolated from SGs and determined to be a 24 amino acid peptide amide. The cDNA encodes the polyprotein precursor from which DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides are released and become matured. The C-terminal FXPRL-NH2 sequence of DH is essential but not sufficient for expression of full activity. Recently, we have isolated a unique hydrohobic peptide (VAP peptide) with a slight diapause egg induceing activity from organic solvent extracts of the male adult heads of the silkworm. The VAP peptide itself has no diapause inducing activity, but enhances DH activity through reducing ED50 value and the threshold concentration of DH. The DH-PBAN gene is composed of 6 exons interrupted by 5 introns and is expressed in 12 neurosecretory cells of the SG. The incubation of eggs at 25$^{\circ}C$, which induces embryonic diapause in the progeny, caused DH-PBAN mRNA content to increase at 5 different stages in the life cycle. By contrast, a 15$^{\circ}C$ incubation only induced expression of the gene at the late phrase adult stage. The temperature-controlled expression of DH-PBAN gene is closely correlated to the incidence of diapause, indicating that DH-PBAN gene expression is the initial event leading to diapause induction. DH acts to stimulate trehalase activity in developing ovary to bring about hyprglycogenism in mature eggs, a prerequisite metabolism for diapause initiation. Using in vivo and in vitro systems, DH is clearly shown to induce trehalase gene expression in developing ovaries. New protein synthesis is not needed for this process, but a Ca2+-dependent proteinkinase seems to be involved. Quite recently, we have sucessfully applied a new and potent trehalase inhibitor (Trehazoline) to reudce glycogen content in developing ovaries. The eggs deficient in glycogen were also able to enter diapause as the natural eggs do, so that we could provide the new egg system to reconsider the diapause associated metabolism other than the glycogen-sorbitol metabolic system.