• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.774-776
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• 1994

Ab initio studies of simple model systems for the carboxypeptidase A active site indicate that penta-and hexa-coordinate Zn(II) complexes have comparable structural stabilities. These facile coordination structures can be responsible for the catalytic role. Although the hexa-coordinate Zn(II) complex is more stable in enthalpy than the penta-coordinate Zn(II) complex, the entropy effect makes the latter as stable as or slightly more stable in free energy than the former.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.61-66
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• 2014

This paper describes the design, fabrication, and measurement of a compact hexa-band coupling antenna for 4G mobile handset using a small element with two slots. In order to obtain sufficient bandwidth (LTE700, GSM850, GSM900, GSM1800, GSM1900, UMTS) with a Voltage Standing Wave Ratio $(VSWR){\leq}3:1$, two slots are inserted in the small element, and coupling patch is used. The measured result of the fabricated antenna provides 410MHz bandwidth form 0.688 to 1.098GHz and 643 MHz bandwidth form 1.607 to 2.250GHz (${\leq}VSWR 3:1$) with the gain ranging from -0.52 to 4.68 dBi. Also, a good radiation pattern is achieved within the hexa-band (0.698-0.960GHz and 1.710-2.170GHz) range.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2737-2742
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• 2003

Kinematic calibration enhances absolute accuracy by compensating for the fabrication tolerances and installation errors. Effectiveness of calibration procedures depends greatly on the measurements performed. While the Cartesian postures are measured completely, all of the geometric parameters can be identified to their true values. With partial pose measurements, however, few geometric parameters may not be identifiable and effectiveness of the calibration results may vary significantly within the workspace. QR decomposition of the identification Jacobian matrix can reveal the non-identifiable parameters. Selecting postures for measurement is also an important issue for efficient calibration procedure. Typically, the condition number of the identification Jacobian is minimized to find optimum postures. This paper investigates identifiable parameters and optimum postures for four different calibration procedures - measuring postures completely with inverse kinematic residuals, measuring postures completely with forward kinematics residuals, measuring only the three position components, and restraining the mobility of the end-effector using a constraint link. The study is performed for a six degree-of-freedom fully parallel HexaSlide type paralle manipulator, HSM. Results verify that all parameters are identifiable with complete posture measurements. For the case of position measurements, one and for the case of constraint link, three parameters were found non-identifiable. Optimal postures showed the same trend of orienting themselves on the boundaries of the search space.

• Biomedical Science Letters
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• v.27 no.3
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• pp.187-194
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• 2021

Platelets are derived from fragments formed in the cytoplasm of bone marrow megakaryocytes. Platelet count (PLT) can be altered by factors such as platelet production, destruction, and inflammation. In a previous study, the significant single nucleotide polymorphisms (SNP) were reported by the genome-wide association study (GWAS) for PLT in Koreans. In this study, it was confirmed whether significant SNPs were replicated in the HEXA (The Health Examinees) cohort. As a result, the SNPs of the THPO (rs6141), BAK1 (rs210314, rs9296095), GGNBP1 (rs75080135), ACAD10 (rs6490294), and ABCC4 (rs4148441) were significantly correlated with PLT (P < 10^-8). At the same time, it was confirmed that the direction of influence was the same according to the genotype. In conclusion, it can be seen that common SNPs are associated with the platelet count regardless of the cohort for Koreans.

• Journal of the Korean institute of surface engineering
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• v.54 no.1
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• pp.37-42
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• 2021

Electrodeposition is a synthetic method that allows fine control of the nucleation and growth factors of metals and is a suitable method for studying the nucleation and growth of Ni(OH)2. Hexa-methylenetetramine (HMT) helps to form Ni(OH)2 nanosheets by increasing the OH- of the nickel precursor solution and helps to improve the electrochemical properties of the electrode. In this study, the structural properties of Ni(OH)2 nanosheets according to the HMT concentration change using electrodeposition were studied. As the concentration of HMT increased, the size and thickness of the Ni(OH)2 nanosheet adsorbed on the surface increased and porosity increased. Also, the Scharifker-Hills nucleation theory model and experimental data were compared. In conclusion, the nanosheet shape of the HMT 7.5 mM sample electrodeposited with -0.85 V vs. Ag/AgCl grew most uniformly, and the best result was obtained as an electrode material for a pseudocapacitor.

• Proceedings of the Korean Fiber Society Conference
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• 1988.06a
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• pp.15-15
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• 1988

• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.13-23
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• 2002

This paper presents inverse kinematic and dynamic analyses of HexaSlide type six degree-of-freedom parallel manipulators. The HexaSlide type parallel manipulators (HSM) can be characterized as an architecture with constant link lengths that are attached to moving sliders on the ground and to a mobile platform. In the inverse kinematic analyses, the slider and link motion (position, velocity, and acceleration) is computed given the desired mobile platform motion. Based on the inverse kinematic analysis, in order to compute the required actuator forces given the desired platform motion, inverse dynamic equations of motion of a parallel manipulator is derived by the Newton-Euler approach. In this derivation, the joint friction as well as all link inertia are included. Relative importance of the link inertia and joint frictions on the computed torque is investigated by computer simulations. It is expected that the inverse kinematic and dynamic equations can be used in the computed torque control and model-based adaptive control strategies.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.5
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• pp.6-11
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• 1975

반복형 그래이 부호 중 14진 및 16진 부호용 디지트 절차(digit sequence 또는 DS)의 여러가지 특성에 관하여 논하였으며 그것들을 통일적으로 기적할 수 있는 PDS는 각각 31종 및 11종이 있다는 것을 명백히 하였다. 그리고 이 PDS들에 회전변환과 순렬변환을 실시하여 얻을 수 있는 DS의 총수와 각종 특수 DS의 성질에 관하여도 논하였으며 대칭형 DS를 이용한 14진 및 16진 GC Counter를 설계하여 그것들의 동작을 실험에 의하여 확인하였다. Investigations on some characteristics of Tetra-Decimal and Hexa-Decimal recycling Gray co de (GC)-digit sequence(DS) are carried out, and, 31 and 11 kinds of prime digit sequence(PDS) are proposed respectively. From these PDS, by means of rotational conversion and permutational conversion, the numbers of all DS are obtained, and also the characteristics of some special DS are studied. Tetra Decimal and Hexa-decimal GC counters are designed using symmetrical DS, and, their operations are experimentally verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.197-203
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• 2005

This paper presents kinematic calibration of parallel manipulators with partial pose measurements using a device that measures a rotation of the end-effector along with its position. The device contains an LVDT, a biaxial inclinometer, and a rotary sensor and facilitates automation of the measurement procedure. The device is designed in a modular fashion and links of different lengths can be used. The additional kinematic parameters required for the measurement device are discussed, kinematic relations are derived, and cost function is established to perform calibration with the proposed device. The study is performed for a six degree-of-freedom(DOF) fully parallel HexaSlide Mechanism(HSM). Experimental results show significant improvement in the accuracy of the HSM.

• Macromolecular Research
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• v.15 no.4
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• pp.348-356
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• 2007

The aim of this study was to fabricate a submicro-and micro-patterned fibronectin coated wafer for a cell culture, which allows the positions and dimensions of the attached cells to be controlled. A replica molding was made into silicon via a photomask in quartz, using E-beam lithography, and then fabricated a polydimethylsiloxane stamp using the designed silicon mold. Hexadecanethiol $[HS(CH_2){_{15}}CH_3]$, adsorbed on the raised plateau of the surface of polydimethylsiloxane stamp, was contact-printed to form self-assembled monolayers (SAMs) of hexadecanethiolate on the surface of an Au-coated glass wafer. In order to form another SAM for control of the surface wafer properties, a hydrophilic hexa (ethylene glycol) terminated alkanethiol $[HS(CH_2){_{11}}(OCH_2CH_2){_6}OH]$ was also synthesized. The structural changes were confirmed using UV and $^1H-NMR$ spectroscopies. A SAM terminated in the hexa(ethylene glycol) groups was subsequently formed on the bare gold remaining on the surface of the Aucoated glass wafer. In order to aid the attachment of cells, fibronectin was adsorbed onto the resulting wafer, with the pattern formed on the gold-coated wafer confirmed using immunofluorescence staining against fibronectin. Fibronectin was adsorbed only onto the SAMs terminated in the methyl groups of the substrate. The hexa (ethylene glycol)-terminated regions resisted the adsorption of protein. Human dermal fibroblasts (P=4), obtained from newborn foreskin, only attached to the fibronectin-coated, methyl-terminated hydrophobic regions of the patterned SAMs. N-HDFs were more actively adhered, and spread in a pattern spacing below $14{\mu}m$, rather than above $17{\mu}m$, could easily migrate on the substrate containing spacing of $10{\mu}m$ or less between the strip lines.