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Cr(III)-Tetraaza Macrocyclic Complexes Containing Auxiliary Ligands (Part III); Synthesis and Characterization of Cr(III)-Isothiocyanato, -Azido and -Chloroacetato Macrocyclic Complexes

  • Byun, Jong-Chul;Han, Chung-Hun;Park, Yu-Chul
    • Bulletin of the Korean Chemical Society
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    • v.26 no.7
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    • pp.1044-1050
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    • 2005
  • The reaction of cis-[Cr([14]-decane)($OH_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = isothiocyanate ($NCS^-$), azide ($N3^-$) or chloroacetate(caa)} leads to a new cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ (1), cis-[Cr([14]-decane)($N_3)_2]ClO_4$ (2) or cis-[Cr([14]-decane)($caa)_2]ClO_4$ (3). These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ reveals that central chromium(III) has a distorted octahedral coordination environment and two $NCS^-$anions are bonded to the chromium(III) ion via the Ndonor atom in the cis positions. The angle $N_{axial}-Cr-N_{axial}$ deviates by 13$^{\circ}$ from the ideal value of 180$^{\circ}$ for a perfect octahedron. The bond angle N-Cr-N between the Cr(III) ion and the two nitrogen atoms of the isothiocyanate ligands is close to 90$^{\circ}$. The bond lengths of Cr-N between the chromium and $NCS^-$groups are 1.964(5) and 2.000(5) $\AA$. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 2073, 1344 and 1684 $cm^{-1}$ attributed to the $NCS^-$, ${N_3}^-$ and caa groups stretching vibrations, respectively.

Electronic Spectroscopy and Ligand Field Analysis of trans-[CrX2([15]aneN4)]+(X=F,CI) (trans-[CrX2([15]aneN4)]+(X=F,CI)의 전자분광학과 리간드장 해석)

  • Jong-Ha Choi;In-Gyung Oh;Sang Hak Lee;Yu Chul Park
    • Journal of the Korean Chemical Society
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    • v.47 no.2
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    • pp.109-114
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    • 2003
  • The electronic absorption spectra of trans-$[CrX_2([15]aneN_4)]ClO_4\;([15]aneN_4$=1,4,8,12-tetraazacyclopentadecane; X=F, Cl) complexes have been interpreted using the ligand field theory. An AOMX program is used to optimize the differences between the calculated and the observed positions for the spin-allowed transition bands. The crystal field theory(CFT) parameter is directly related to the angular overlap model(AOM), normalized spherical harmonic hamiltonians(NSH), and semiempirical parameters. The various ligand field parameters are discussed in terms of their chemical significances. According to the ligand field analysis, we can confirm that the fluoride ligand is a very strong ${\sigma}-$ and ${\pi}-$donor while the chloride has weak ${\sigma}-$ and ${\pi}-$donor properties toward chromium(III) ion.

The Impact of Social Capital of Manufacturing Companies on Relationship Performance (제조기업의 사회자본이 공급사슬 관계 성과에 미치는 영향)

  • Noh, Hyeyoung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.3
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    • pp.143-155
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    • 2020
  • The relationship between companies in the supply chain is a core competency of the company and key indicator which determines the survival of a company. Therefore, companies are investing in efforts for inter-company relations, and related studies have been conducted for a long time. However, in the supply chain, the positions and characteristics of suppliers and buyers are not the same. Therefore, research is needed to better understand and respond to other characteristics of the relationship between suppliers and buyers. The purpose of this study was to identify the characteristics of the resources held between the buyer and the supplier through social capital, which is a value asset that can be used as a resource created through social relations, and whether it affects the commitment of the relationship. In addition, The core of this study was to statistically analyze the differences between suppliers and buyers through this analysis. This study was conducted by surveying companies that are suppliers and buyers along the supply chain. The difference between the supplier and the buyer was revealed through empirical analysis, and statistically, the difference between the two groups was also revealed. As a result of the analysis, the higher the involvement of the buyer, the more significant the result of structural capital was, and the result was statistically opposite to the supplier. As for the relationship capital, quantitative and qualitative relationship capital had different effects on the commitment. Both the supplier and the buyer had a positive effect on relationship performance. However, the effect of emotional commitment on non-financial relationship performance has a greater degree of influence on suppliers, and it appears in statistical differences. This study revealed differences in the relationship between suppliers and buyers, and found that different investments and efforts were required for each group.

Small group of protostellar objects: L1251C

  • Kim, Jungha;Lee, Jeong-Eun;Choi, Minho
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.51.1-51.1
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    • 2013
  • We present molecular line observations of a small group of Young Stellar Objects (YSOs), L1251C. Observations by Spitzer Space Telescope legacy program "From Molecular Cores to Planet Forming Disks"(c2d; Evans et al. 2003) revealed that there are three YSOs within ~15" in L1251C: IRS1 (Class I), IRS2 (Class II), and IRS3 (Class II). In order to understand the molecular environment around these YSOs, we carried out the KVN single-dish observations in $HCO^+$ J=1-0, $H^{13}CO^+$ J=1-0, $N_2H^+$ J=1-0 and HCN J=1-0. CO J=1-0 was also mapped in L1251C with the TRAO 14m telescope. Integrated intensity maps of high density tracers such as $H^{13}CO^+$ J=1-0, $N_2H^+$ J=1-0 and HCN J=1-0 show similar emission distributions, whose peaks are off from the positions of YSOs. However, $HCO^+$ J=1-0, which is believed to trace both infall and outflow, presents its emission distribution different from those of other molecular transitions. The line profile of $HCO^+$ J=1-0 is superimposed by two velocity (narrow and broad) components. The $HCO^+$ outflow map reveals multiple structures while the CO outflow map elongates mainly along the EW direction. With the KVN single dish, the 22 GHz $H_2O$ maser emission has been also monitored toward L1251C to find variations of the systemic velocity and intensity with time.

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The Effects of Sciatic Nerve Mobilization on Hamstring Flexibility, Lower Limb Strength and Gait Performance in Patients With Chronic Stroke

  • Shin, Yun-hyeok;Chon, Seung-chul
    • Physical Therapy Korea
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    • v.22 no.4
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    • pp.8-16
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    • 2015
  • The purpose of this study was to evaluate the effects of mobilization of the sciatic nerve on hamstring flexibility, lower limb strength, and gait performance in patients with chronic stroke. This study was a randomized clinical trial with a crossover design. Sixteen subjects were recruited for this study. The subjects were randomly divided into two intervention groups and underwent either of the following two interventions: sciatic nerve mobilization or static stretching of the hamstring. We assessed hamstring flexibility, lower limb strength, and gait performance using a digital inclinometer, a hand-held dynamometer, and the 10-meter walk test, respectively. Subjects had a 24-hour rest period between each session in order to minimize carryover effects. Measurements for each test were assessed prior to and immediately after the intervention sessions. Using a two-way analysis of variance test with repeated measures, data from the two trials were analyzed by comparing the differences between both techniques. The level of statistical significance was set at .05. Sciatic nerve mobilization resulted in significantly better knee extensor strength (p=.023, from $15.32{\pm}5.98$ to $18.16{\pm}6.95kg$) and knee flexor strength (p=.011, from $7.80{\pm}4.80$ to $8.15{\pm}4.24kg$) in the experimental group than in the control group. However, no significant effects of static stretching of the hamstring were observed on hamstring flexibility from the ankle plantar flexion (p=.966) and ankle neutral positions (p=.210) and on gait performance (p=.396). This study indicated that the sciatic nerve mobilization technique may be more effective in muscle activation of the knee extensor muscle and knee flexor muscle than hamstring static stretching technique in patients with chronic stroke.

A Study of the Librarian Personnel for Public Libraries on the Lump-sum Personnel Expenditure System (공무원 총액인건비제에서 공공도서관 사서직 인력에 대한 고찰)

  • Kwak, Chul-Wan;Kim, Sun-Yi;Kim, Su-Joung;Song, Jae-Sul;Yoon, Myung-Hee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.23 no.3
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    • pp.211-230
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    • 2012
  • The purpose of this study is to identify the influence of the change on librarian number of local governments on the lump-sum personnel expenditure system. Data were collected and analyzed from the Enhanced local laws and regulations information system and local government home pages of 15 local governments where opened more than two public libraries from 2008 to 2010. Results show that the number of 15 government employees was increased but the number of librarian was slightly increased. Also, the number of administrative positions was increased using plural series position system. It shows that the number of librarian can be increased under the lump-sum personnel expenditure system.

Realistic Keyboard Typing Motion Generation Based on Physics Simulation (물리 시뮬레이션에 기반한 사실적인 키보드 타이핑 모션 생성)

  • Jang, Yongho;Eom, Haegwang;Noh, Junyong
    • Journal of the Korea Computer Graphics Society
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    • v.21 no.5
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    • pp.29-36
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    • 2015
  • Human fingers are essential parts of the body that perform complex and detailed motion. Expression of natural finger motion is one of the most important issues in character animation research. Especially, keyboard typing animation is hard to create through the existing animation pipeline because the keyboard typing typically requires a high level of dexterous motion that involves the movement of various joints in a natural way. In this paper, we suggest a method for the generation of realistic keyboard typing motion based on physics simulation. To generate typing motion properly using physics-based simulation, the hand and the keyboard models should be positioned in an allowed range of simulation space, and the typing has to occur at a precise key location according to the input signal. Based on the observation, we incorporate natural tendency that accompanies actual keyboard typing. For example, we found out that the positions of the hands and fingers always assume the default pose, and the idle fingers tend to minimize their motion. We handle these various constraints in one solver to achieve the results of real-time natural keyboard typing simulation. These results can be employed in various animation and virtual reality applications.

Behavior and Failure Mode of Steel Coupling Beams Joint with FBP (FBP가 설치된 철골 커플링보 접합부의 거동 및 파괴모드)

  • Song Han-Beom;Yi Waon-Ho
    • Journal of the Korea Concrete Institute
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    • v.17 no.6 s.90
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    • pp.1001-1009
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    • 2005
  • The usefulness of walls in the structural planning of multistory buildings has long been recognized. When walls are situated in advantageous positions in a buildings, they can be very efficient in resisting lateral load. Specially coupled shear wall system is the primary lateral load resisting system of buildings. It is customary to refer to such walls as being 'coupled' by coupling beams. The coupling beams must exhibit excellent strength, stiffness ductility and energy dissipation capacity. To achieve these demands for steel coupling beam, steel coupling beam with Face Bearing Plate(FBP) embedded in the reinforced concrete walls is proposed. A comprehensive experimental test involving 2 steel coupling beam with and without FBP has been performed. Through experimental study, the evaluation of the advantage of that was establish and proposed the failure mode.

Prediction of Differential Drying Shrinkage in Concrete (콘크리트의 부등건조수축에 관한 연구)

  • 김진근;이칠성
    • Magazine of the Korea Concrete Institute
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    • v.9 no.2
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    • pp.153-161
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    • 1997
  • In the concrete st~uctures exposed to the environmental condition, the water movement is occurred by thc moisture difilsion, and the rnoisturrt distribution in concwt.c is nonunifhrm. Such a non-unif'orm moisture distribution causes tht. diflbrent.ia1 drying shrinkage in concrete structures. From this typc. of' dif'fercntial drying shrinkagr' tensiit-1 stress is occurred in exposure surface of concrete structures. and may result in crack formation. This residual stress is significantly affected by the creep of concrete, and the differential creep is also occurred at the cross section of concrete structures due to moisture difference at each locations. In this study, based on the moisture diffusion theory, a finite element program which is capable of simulating the moisture distribution in concrete was developed. And the analysis method for the differential drying shrinkage was suggested, in which the differential creep was considered. The differential drying shrinkage strain was also measured at various positions of concrete. Finally the validity of analysis method was proved by comparing test results with analytical results.

Teaching and learning(PBL) and explore the convergence of the Effects of the practical skills (교수-학습(PBL)과 실무능력의 융합 및 적용 효과 탐색)

  • Kim, Soo-Yeon
    • Journal of the Korea Convergence Society
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    • v.7 no.2
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    • pp.109-118
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    • 2016
  • The purpose of this study was I cultivate practical ability to solve diverse and complex issues in the field of convergence and applied learning and practical training element through problem-based learning to preliminary sports leaders. Selected students in grades 3 to 28 Sports Science S university people to them as participants and through a qualitative case study methods, such as group interviews, participant observation, open questionnaire and the following results were obtained. First, the level of satisfaction on class was high and the class was evaluated with significant contemplation. Second, it has been collecting a variety of learning materials to understand, interpret and improve the ability to solve practical problems in the process of actively reconstruct their own knowledge structure. It also gave a positive impact on the creative and divergent thinking to accelerate the promotion of autonomy. Third, opinions about teamwork, sharing your thoughts with colleagues point is that you can see yourself in other people's positions were evaluated as positive effects.