• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.318-325
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• 2022

In this study, composites containing undoped and barium-doped Bi₂WO₆:Ba²⁺were investigated for their shielding against diagnostic X-ray. At first, Bi₂WO₆ and barium-doped Bi₂WO₆ were synthesized with different weight percentages of barium oxide through a hydrothermal process. The as-synthesized nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy (RS). After that, some shields were generated with undoped and barium-doped Bi₂WO₆:Ba²⁺ nanostructure particles incorporated into polyvinyl chloride (PVC) polymer with different thicknesses and 15% weight of the nanostructure. Finally, the prepared samples were exposed to an X-ray tube at 40, 80, and 120 kV voltages, 10 mAs and, 44.5 cm SID (i.e. the distance from the X-ray beam source to the specimen). Linear and mass attenuation coefficients were also calculated for different samples. The results indicated that, among the samples, the one with 7.5 mmol barium-doped Bi₂WO₆ had the most attenuation at the voltage of 40kV, and the attenuation coefficients would increase with an increase in the amount of barium. The samples with 15 and 17.5 mmol barium-doped Bi₂WO₆ had higher attenuation than the others at 80 and 120 kV. Moreover, the half-value layer (HVL), tenth-value layer (TVL) and 0.25 mm lead equivalent thickness were calculated for all the samples. The lowest HVL value was for the sample with 7.5 mmol barium-doped Bi₂WO₆. As the result clearly show, an increment in the barium-doping content leads to a decrease in both HVL and TVL. In every three voltages, 0.25 mm lead equivalent thickness of the barium-doped composites (7.5 mmol and 15 mmol) had less than the other composites. The lowest value of 0.25 mm lead equivalent thickness was 7.5 barium-doped in 40 kV voltage and 15 mmol barium-doped in 80 kV and 120 kV voltages. These results were obtained only for 15% weight of the nanostructure.

• Kyungpook Mathematical Journal
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• v.61 no.4
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• pp.679-710
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• 2021

We study the tensor product algebra P_k(x₁) ⊗ P_k(x₂) ⊗ ⋯ ⊗ P_k(x_m), where P_k(x) is the partition algebra defined by Jones and Martin. We discuss the centralizer of this algebra and corresponding Schur-Weyl dualities and also index the inequivalent irreducible representations of the algebra P_k(x₁) ⊗ P_k(x₂) ⊗ ⋯ ⊗ P_k(x_m) and compute their dimensions in the semisimple case. In addition, we describe the Bratteli diagrams and branching rules. Along with that, we have also constructed the RS correspondence for the tensor product of m-partition algebras which gives the bijection between the set of tensor product of m-partition diagram of P_k(n₁) ⊗ P_k(n₂) ⊗ ⋯ ⊗ P_k(n_m) and the pairs of m-vacillating tableaux of shape [λ] ∈ Γ_k^m, Γ_k^m = {[λ] = (λ₁, λ₂, …, λ_m)|λ_i ∈ Γ_k, i ∈ {1, 2, …, m}} where Γ_k = {λ_i ⊢ t|0 ≤ t ≤ k}. Also, we provide proof of the identity $(n_1n_2{\cdots}n_m)^k={\sum}_{[{\lambda}]{\in}{\Lambda}^k_{{n_1},{n_2},{\ldots},{n_m}}}$ f^[λ]m_k^[λ] where m_k^[λ] is the multiplicity of the irreducible representation of $S{_{n_1}}{\times}S{_{n_2}}{\times}....{\times}S{_{n_m}}$ module indexed by ${[{\lambda}]{\in}{\Lambda}^k_{{n_1},{n_2},{\ldots},{n_m}}}$, where f^[λ] is the degree of the corresponding representation indexed by ${[{\lambda}]{\in}{\Lambda}^k_{{n_1},{n_2},{\ldots},{n_m}}}$ and ${[{\lambda}]{\in}{\Lambda}^k_{{n_1},{n_2},{\ldots},{n_m}}}=\{[{\lambda}]=({\lambda}_1,{\lambda}_2,{\ldots},{\lambda}_m){\mid}{\lambda}_i{\in}{\Lambda}^k_{n_i},i{\in}\{1,2,{\ldots},m\}\}$ where ${\Lambda}^k_{n_i}=\{{\mu}=({\mu}_1,{\mu}_2,{\ldots},{\mu}_t){\vdash}n_i{\mid}n_i-{\mu}_1{\leq}k\}$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.3
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• pp.195-205
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• 2020

This study addresses analysis on reactions which are induced in restraint system for airframe full-scale static structural test. This system restraints 6 degrees of freedom of a test article. It is valuable to study evaluating test error through analysis on the reactions which include all errors in a test. It is required to calculate fistly right reactions for the evaluation. This study focuses on calculation of the right reactions. The reaction is represented by sum of nominal reaction(Rn) and testing error reactions(Rce, Rerr) and is analyzed by two steps (inital vs relative reaction) in this study. It would evaluate intrinsic error at 0%DLL and error induced from applying test load, separately. Based on analysis using test data of a full-scale static test(canard type aircraft), resultant force of Rces and Rce_rs are distributed within 82.8N while resultant force of Rerr_rs shows to increase upto max. 808N as load level increment. Such well distribution of the Rce within the small range is caused from TMF values characteristics which are well distributed within -30N~40N. Additionally, it is shown through qualitative analysis on three components(X0, Y0, Z0) of the relative reaction(Rerr_r) that the reactions must be calculated with considering deformation of test article to calculate correctly reactions. This study shows also that equations characterizing deformation of components of test article are required to calculate the correct reactions, the equations must include information which will be used to calculate movement of all loading points.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.553-558
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• 2011

This paper describes the development and test result of S-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels, S-band for Telemetry & Command and X-band for mission data. S-band Transmitter(STX) functionally made of modulator, frequency synthesizer, power amp and DC/DC converter. The transmission data is modulated by FSK(Frequency Shift Keying) and the interface between spacecraft sub-module and STX is RS-422 standard method. The FM STX is based on modular design. The RF output power of STX is 1.5W(31.7dBm) and BER of STX is under $1{\times}10^{-5}$ which meets the specification respectively. The FM STX is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

• Analytical Science and Technology
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• v.18 no.4
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• pp.278-286
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• 2005

The crystal structure of ($Tl_{71}$-Y ($Tl_{71}Si_{121}Al_{71}O_{384}$), ${\alpha}=24.706(3){\AA}$, dehydrated at 653 K and $8{\times}10^{-6}$ torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group $Fd\bar{3}m$ at 294(1) K. The structure was refined using all intensities to the final error indices (using only the 302 reflection for which $F_{\circ}$ > $4{\sigma}(F_0)$) $R_1=0.0602$ (based on F) and $R_w=0.1744$ (based on $F_2$). The 71 $Tl^+$ ions per unit cell are found at four crystallographically distinct positions. Site I' position in the sodalite cavity opposite D6Rs are each occupied by eighteen $Tl^+$ ions per unit cell; these $Tl^+$ ions are recessed ca. $1.45{\AA}$ into the sodalite cavity from their O(3) plane (Tl-O=2.701(15), $3.163(16){\AA}$ and O-Tl-O=$92.1(4)^{\circ}$). The 23 $T1^+$ ions fill site II in the supercage; these $T1^+$ ions are recessed ca. $1.58{\AA}$ into the supercage from their O(2) plane (Tl-O = 2.850(16), $3.156(16){\AA}$ and O-T1-O = $85.1(5)^{\circ}$). The 19 $Tl^+$ ions lie at site III' in the supercage near a triple 4-ring (Tl-O = 3.10(7), $3.39(5){\AA}$ and O-Tl-O = 47.8(9), $95.3(18)^{\circ}$) and the remaining II ions occupy another site III' near a triple 4-ring in the supercage (Tl-O = 2.81(4), $2.71(4){\AA}$ and O-Tl-O = $57.3(8)^{\circ}$).

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.267-284
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• 2012

In most of the design offices, analysis of the frame is carried out without considering the effect of the rigidity of mat. The analysis of the superstructure without modelling the foundation properly and conversely analysing the foundation system without considering the stiffness of the superstructure may mislead the estimation of the forces. This paper examines the parameters, which affect the interaction and they are grouped into relative stiffness factors ${\kappa}_{rs}$ and ${\kappa}_{sb}$. An interaction analysis is performed for the five storeyed space frame of 3 bays ${\times}$ 5 bays, using ANSYS finite element code. The soil was treated as an isotropic, homogenous and elastic half space medium and the following conclusions were drawn from the analyses. The differential settlement is reduced due to interaction and the performance of the mat depends on ${\kappa}_{sb}$ values. The moments $M_x$ and $M_y$ in the corner column at all the storey levels are higher in the case of the interaction analysis than in the conventional analysis. The axial forces in the peripheral columns increased and to that extent, the inner column axial loads are reduced. In the beam, more variation is seen in the support moments than in the span moments.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.207-212
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• 2016

PacBio's long-read sequencing technologies can be successfully used for a complete bacterial genome assembly using recently developed non-hybrid assemblers in the absence of second-generation, high-quality short reads. However, standardized procedures that take into account multiple pre-existing second-generation sequencing platforms are scarce. In addition to Illumina HiSeq and Ion Torrent PGM-based genome sequencing results derived from previous studies, we generated further sequencing data, including from the PacBio RS II platform, and applied various bioinformatics tools to obtain complete genome assemblies for five bacterial strains. Our approach revealed that the hierarchical genome assembly process (HGAP) non-hybrid assembler resulted in nearly complete assemblies at a moderate coverage of ~75x, but that different versions produced non-compatible results requiring post processing. The other two platforms further improved the PacBio assembly through scaffolding and a final error correction.

• Journal of Korean Academy of Nursing
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• v.17 no.1
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• pp.79-87
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• 1987

Study was to identify the structural and functional characteristics of social support system to better provide social support to physically handicapped children. The research design was a comparative descriptive study and the data were obtained by use of interview and questionnaire. The result of this were as follows: 1. The physically handicapped children perceived that they had a fewer number of social support providers than the non-handicapped children. (t= -4.62, p<.001) 2. The physically handicapped children Perceived a lower level of social support than the non-handicapped children. (t= -3.93, p<.001) In the cases of 3 types of social support (social integration, attachment / intimacy, assistance/guidance), the handicapped children perceived a lower level of social support. 3. It was found that physically handicapped children and nonhandicapped children perceived degree of social support differently (x$^2$=72.08, p<.001). and also the two groups perceived in all types of social support differently. 4. The results of this study showed that parents, school mates, school teachers, brothers and sisters were significant providers of social support and between the two groups the supportive source ranked consistently. (rs=.83, p<.01) 5. The relationship between sociability and the support level was a positive correlation (r=.28, p<.01), the relationship between sociability and the size of the support network showed a positive correlation. (r=.47, p<.01) And with the increase in the number of friends. the number of support providers increased. (F= 4.46, p<.05).

• Journal of Chest Surgery
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• v.20 no.3
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• pp.528-535
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• 1987

A clinical study was performed on 164 cases of PDA experienced at the Dept. of Thoracic and Cardiovascular Surgery of Pusan National University Hospital during 6 years from Jan. 1981 to Dec. 1986. It was shown that the PDA was a female-dominant heart disease [male to female ratio, 1:2.8] and two most common symptoms were frequent URI [45.6%] and exertional dyspnea [36.7%]. Continuous machinery murmurs were detected in 143 cases [87.2%], increased pulmonary vascularities [89.0%] and cardiomegalies [63.4%] by chest X-ray. The signs of LVH [43.9%], RVH [3.7%] and BVH [4.9%] were noted on the EKG. Cardiac catheterizations were performed on 67 out of 164 patients and the mean systolic pulmonary artery pressure was 48mmHg [range: 18-131mmHg] and the mean Qp/Qs was 3.1 [range:1.2-8.5] and Rp/Rs below 0.25 was 83.6%. Associated cardiac anomalies were VSD [7.9%], ASD [3.0%], pulmonary valvular stenosis [2.4%] and left persistent SVC [2.4%]. Operative methods were as follows; ligations [145; 88.4%] and divisions [6;3.7%] were performed through the left posterolateral thoracotomies without mortality and the remained cases [13;8.0%] were managed under the cardiopulmonary bypass because of the associated cardiac anomalies. Atelectasis [4.9%] and pneumonia [4.3%] were most frequent postoperative complications and the overall mortality rate was 2.4% [4 out of 164 cases].

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.127-133
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• 2009

We present a $3-{\underline{P}}RS$ compliant parallel manipulator actuated by PZTs. The motion ranges are $400-{\mu}m$ translation to the z-direction and 5.7-mrad rotation about any axis on the x-y plane. A mechanical amplifier whose advantage is approximately 5.5 is designed and integrated with flexure revolute and spherical joints in a monolithic way. We evaluated the performance of the system: kinematic and dynamic characteristics. In kinematic point of view, the flexures play the roles of conventional mechanism but any nonlinearity such as dead-zone and backlash, which make it possible to achieve the steady-state resolution less than $0.1{\mu}m$. The system shows resonance near 86 Hz with high magnitude and, therefore, poor transient response. But the settling is faster when the flexures are strained higher.