• Journal of Sensor Science and Technology
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• v.9 no.1
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• pp.51-60
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• 2000

This paper outlines the development of a non-pulsatile axial flow type blood pump control system. By utilizing blood pressure and heart rate, this system can assist the left ventricle in controlling blood pressure and blood volume. The system is comprised of a blood pump, signal sensor, signal interface, and signal-processing component. A control algorithm is also proposed which can control non-pulsatile, continuous blood flow in the human circulatory system. To facilitate the control required for non-pulsatile blood pump in a physiological system, an experimental control rule was developed utilizing ECG and blood pressure data, both of which are easily detectable variables in the body. The system was then tested using a mock-up circulation system and we found that it is possible that this systems could be temporarily used in clinic.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.365-372
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• 2000

In this study, a multichannel taste sensor using the evanescent field absorption in fiber optic was developed, and evaluated its characteristics for several basic taste substances. This sensor is based on the change of evanescent field absorption at the surface of optical fiber core layer. The sensor device was made of a plastic-clad-silica fiber (3M Co., FP-400-UHT, core diameter $400\;{\mu}m$) and a middle portion of cladding layer was removed and the surface of stripped fiber core was dip-coated with a sensing membrane. And then, it was determined the difference of evanescent field absorption into the sensing membrane, according to various taste substances and its concentrations variance. The sensing membranes were prepared with six kinds of dyes, were known as potential sensitive dye together with silicone polymer the same refractive index of cladding. Each output patterns were obtained from the sensor devices could be distinguished not only five kinds of basic taste substances such as sweetness, saltiness, sourness, bitterness and umami, but also various mixed taste substances.

• Applied Chemistry for Engineering
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• v.23 no.4
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• pp.367-371
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• 2012

Waste printed circuit boards (WPCBs) contain valuable metals such as Cu, Ni, Au, Ag, and Pd. For an effective recycling of WPCBs, it is essential to recover the valuable metals. In recent years, recycling processes have come to be necessary for separating noble metals from WPCBs due to an increasing amount of electronic device wastes. However, it is well known that glass reinforced epoxy resins in the WPCBs are difficult materials to separate into elemental components, namely metals, glass fibers and epoxy resins in the chemical recycling process. $K_3PO_4$ as a catalyst in dimethylformamide (DMF) and N-Methyl-2-pyrrolidone (NMP) was used to depolymerize epoxy resins for recovering metallic and non-metallic components from WPCBs. Reactions of WPCBs were carried out at temperatures $160{\sim}200^{\circ}C$ for 2~12 h. The recycled glass fiber from WPCBs was analyzed by thermogravimetric analyzer (TGA) and evaluated the degree of solubility of the epoxy resin for separation efficiencies of the WPCBs.

• Tuberculosis and Respiratory Diseases
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• v.81 no.2
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• pp.106-115
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• 2018

Chest tube insertion is a common procedure usually done for the purpose of draining accumulated air or fluid in the pleural cavity. Small-bore chest tubes (${\leq}14F$) are generally recommended as the first-line therapy for spontaneous pneumothorax in non-ventilated patients and pleural effusions in general, with the possible exception of hemothoraces and malignant effusions (for which an immediate pleurodesis is planned). Large-bore chest drains may be useful for very large air leaks, as well as post-ineffective trial with small-bore drains. Chest tube insertion should be guided by imaging, either bedside ultrasonography or, less commonly, computed tomography. The so-called trocar technique must be avoided. Instead, blunt dissection (for tubes >24F) or the Seldinger technique should be used. All chest tubes are connected to a drainage system device: flutter valve, underwater seal, electronic systems or, for indwelling pleural catheters (IPC), vacuum bottles. The classic, three-bottle drainage system requires either (external) wall suction or gravity ("water seal") drainage (the former not being routinely recommended unless the latter is not effective). The optimal timing for tube removal is still a matter of controversy; however, the use of digital drainage systems facilitates informed and prudent decision-making in that area. A drain-clamping test before tube withdrawal is generally not advocated. Pain, drain blockage and accidental dislodgment are common complications of small-bore drains; the most dreaded complications include organ injury, hemothorax, infections, and re-expansion pulmonary edema. IPC represent a first-line palliative therapy of malignant pleural effusions in many centers. The optimal frequency of drainage, for IPC, has not been formally agreed upon or otherwise officially established.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.36-42
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• 2007

In general, the battery and the(electric) condenser are pictured as electrical energy storage devices. Although there were lots of inventions and utilizations of morden conveniences according to enormous growth of the science and technologies after the Industrial Revolution, a speed of technology development on these devices being closely used in civilized human lives and many electric or electronic systems as a core component are relatively slower to the other fields of technologies. Nevertheless, based on a remarkable progress of the material science and technologies for the last ten years, a new type of electrical energy storage device so called as 'electrochemical capacitors' are being developed and used practically. The electrochemical capacitors exhibit their own characteristics of much enhanced capacitance over the conventional condensers and also distinctively exhibit a longer lift time and higher power capability that the nickel hydrogen batteries and secondary batteries such as lithium ion and polymer batteries does not show up so for. Hence, in this paper, it is intended to introduce a fundamental understanding and updated technology trends on the electrochemical capacitors.

• Journal of Digital Contents Society
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• v.19 no.5
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• pp.1003-1010
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• 2018

When an applicant requests the emergency situation call or safe return service using a smart device, the smart surveillance service can select the CCTV(closed circuit television) cameras around the applicant using applicant's location information, then automatically takes a photograph to track the applicant. Since the surrounding CCTV camera shoots the applicant continuously using location information and the applicant can be observed by the monitor agent in real time, this service can be very helpful in an applicant's emergency situation or safe return. The existing smart surveillance service does not consider the priority of the emergency situation call and safe return service. Therefore, there is the disadvantage that the applicant who requests an emergency situation call service can not be photographed when safe return service has already preoccupied CCTV cameras which are capable of taking a picture of the applicant. The proposed smart surveillance service improves this disadvantage by using service priority.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.494-500
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• 2014

Indium-doped zinc oxide nanocrystals (IZO NCs), capped with stearic acid (SA) of different sizes, were synthesized using a hot injection method in a noncoordinating solvent 1-octadecene (ODE). The ligand exchange process was employed to modify the surface of IZO NCs by replacing the longer-chain ligand of stearic acid with the shorter-chain ligand of butylamine (BA). It should be noted that the ligand-exchange percentage was observed to be 75%. The change of particle size, morphology, and crystal structures were obtained using a field emission scanning electron microscope (FE-SEM) and X-ray diffraction pattern results. In our study, the 5 nm and 10 nm IZO NCs capped with stearic acid (SA-IZO) were ligand-exchanged with butylamine (BA), and were then spin-coated on a thermal oxide ($SiO_2$) gate insulator to fabricate a thin film transistor (TFT) device. The films were then annealed at various temperatures: $350^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$, and $600^{\circ}C$. All samples showed semiconducting behavior and exhibited n-channel TFT. Curing temperature dependent on mobility was observed. Interestingly, mobility decreases with the increasing size of NCs from 5 to 10 nm. Miller-Abrahams hopping formalism was employed to explain the hopping mechanism insight our IZO NC films. By focusing on the effect of size, different curing temperatures, electron coupling, tunneling rate, and inter-NC separation, we found that the decrease in electron mobility for larger NCs was due to smaller electronic coupling.

• Journal of the Semiconductor & Display Technology
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• v.6 no.2 s.19
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• pp.19-23
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• 2007

The blue emitting OLEDs using TMP-BiP[(4'-Benzoylferphenyl-4-yl)phenyl-methanone-Diethyl(biphenyl-4-ymethyl) phosphonate] host and DJNBD-1 dopant have been fabricated and characterized. In the device fabrication, 2-TNATA [4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] as a hole injection material and NPB [N,N'-bis(1-naphthyl)N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] as a hole transport material were deposited on the ITO(indium tin oxide)/glass substrate by vacuum thermal evaporation method. Followed by the deposition, blue color emission layer was deposited using TMP-BiP as a host material and DJNBD-1 as a dopant. Finally, small molecule OLEDs with structure of $ITO/2-TNATA/NPB/TMP-BiP:DJNBD-l/Alq_3/LiF/Al$ were obtained by in-situ deposition of $Alq_3$, LiF and Al as the electron transport material, electron injection material and cathode, respectively. The effect of dopant into host material of the blue OLEDs was studied. The blue OLEDs with DJNBD-1 dopant showed that the maximum current and luminance were found to be about 34 mA and $8110\;cd/m^2$ at 11 V, respectively. In addition, the color coordinate was x=0.17, y=0.17 in CIE color chart, and the peak emission wavelength was 440 nm. The maximum current efficiency of 2.15 cd/A at 7 V was obtained in this experiment.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.213-220
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• 2009

In this study, we have developed a novel step detection algorithm for gait evaluation of patients with hemiplegia based on trunk accelerometry device. For this, we have used a bandpass filter and a least square acceleration (LSA) filter which is characterized by emphasizing the peak or valley point of the acceleration signals for each 3-axis accelerometer signals. To evaluate the algorithm, the detected steps by developed algorithm and real steps by the motion analysis system were compared. As a result, we could obtain the sensitivity of 96.44%, the specificity of 99.94% and the accuracy of 99.90% for the patients' data sets and the sensitivity of 100%, the specificity of 99.93% and the accuracy of 99.93% for the normal data sets. In conclusion, the developed algorithm is useful for the step detection for patients with hemiplegia as well as normal subjects.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.3
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• pp.112-117
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• 2018

The metal alkoxide, CuCo-glycerate nanospheres (NSs), were successfully synthesized as Cu-Co bimetallic sulfides hierarchical multi-shelled hollow nanospheres ($CuCo_2S_4$ HMHNSs) through solvothermal synthesis. In this reaction mechanism, the solvothermal temperature and the amount of glycerol as a cosurfactant play significant role to optimize the morphology of CuCo-glycerate NSs. Furthermore, $CuCo_2S_4$ HMHNSs were obtained under optimized sulfurization reaction time of 10 h via anion exchange reaction between glycerate and sulfur ions. Finally, the structural and chemical compositions of CuCo-glycerate NSs and $CuCo_2S_4$ HMHNSs were confirmed through field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and electrochemical performances.