• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.242-246
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• 2018

This is the first report of Scomberoides lysan (Perciformes: Carangidae) from Korea. Two specimens (334 and 354 mm standard length) were collected by a set net from the coastal waters of Jejudo Island on 30 September, 2010. This species is characterized and distinguishable from a morphologically similar Scomberoides tol as follows. It has the posterior end of maxilla reaching to the posterior margin of eye (vs. not reaching in S. tol) and two rows of 5~8 small blotches on both sides of body (vs. one row of blotches). We add S. lysan to the Korean fish fauna and propose a new Korean name, "Du-jeom-jul-ga-si-jeon-gaeng-i" for the species because it has two series of dusk blotches on both sides of body.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.877-883
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• 1998

Background: Cardiopulmonary bypass(CPB), a standard adjunct for open heart surgery, can also play an important role in treating patients with noncardiac diseases. Material and Method: We report a collective analysis of noncardiac applications of cardiopulmonary bypass experienced at Seoul National University Hospital from 1969 to 1996. Out of a total of 20 patients, 8 were treated for membranous obstruction of inferior vena cava(MOVC), 5 for malignant melanoma, 3 for pulmonary embolism, 1 for double lung transplantation, 1 for intracranial giant aneurysm(GA), 1 for renal cell carcinoma(RC), and 1 for liposarcoma. CPB was used to induce profound hypothermia with circulatory arrest in 6 patients(MOVC 4, GA 1, RC 1). Result: CPB time was 113 mins on average for MOVC, 161 mins for GA, and 156 mins for RC, while the lowest rectal temperature was 26$^{\circ}C$ on average in MOVC, and 19$^{\circ}C$ in GA and RC. Postoperative recovery was good in all MOVC patients. The patient with GA, who underwent reoperation for the removal of hematoma, died 14 days postoperatively. The patient with RC recovered from the operation in a good condition but died from metastatic spread 6 months later. CPB was instituted for pulmonary embolectomy in 3 patients, in whom postoperative courses were uneventful, except in 1 patient who showed transient neurologic symptoms. CPB was used in a patient with double-lung transplantation for hemodynamic and ventilatory support. The patient was weaned successfully from CPB but died from low output and septicemia 19 days postoperatively. CPB without circulatory arrest was used to treat in 4 patients with MOVC. These patients showed good postoperative courses. CPB was used to administer high concentrations of chemotherapeutic agents to the extremities in 6 patients(malignant melanoma 5, recurrent liposarcoma 1). CPB time was 153 mins on average. No complications such as edema and neurologic disability were found. Conclusion: Although CPB has a limited indication in noncardiac diseases, if properly applied, it can be a very useful adjunct in a variety of surgical cases.

• Journal of Sericultural and Entomological Science
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• v.41 no.1
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• pp.20-28
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• 1999

Color qualities investigated on the basis of Munsell code and Korean standard color code for the cocoons from various strain of mulberry silkworm, Bombyx mori. 16 of different color qualities were identified from 21 of original silworm strains, and determinated international name with the revision of Korean color name for cocoon. The various cocoon color confirmed on the sphere from 567 to 593 nm wavelength, 78% of those located at the region about 580 nm (575~584) of sensitive "color difference limen". Y gene engaged broad ranges of wavelength (575~593 nm) in the color expression, by contrast with other genes of Pk (593 nm), F (584~593), Grc and relative G group (567~570 nm), on the transmission of carotenoid or flavonoid color substance. YC gene expression by original silk worm strain was also distinguished by those variation of specific yellow than other colors from Grc, GaGb, Gc, and YPkF. Appearance of chrome yellow cocoon was dominant than other yellow in the cross among vivid yellow group. F1 of pin${\times}$green produced the cocoon of yellow such as "additive mixture" as color light, however, most of the hybrid between yellow cocoon showed the color similar to "subtractive mixture" as a mixture of dyestuff. Hybrid cocoons among yellow or green colors were decreased their hue, value, and chroma, than those of parent. Diallel cross among the strain of various green cocoon suggest the existence of Grc, Ga, Gb, Gc genes. Cream colored cocoon of B. mandarina was differed from other yellow cocoon of Bobyx mori B. mori. Y$^A$ with Ymc showed the similar role of Y with C, therefore, segregated yellow cocoon from the B. mori${\times}$B. mandarina (+$^YC/Y^AYmc$). YC expression of $Y^AY$mc genes might be suppressed by deficiency of outer layer sericin on the middle division of silk giand in the B. mandarina.

• Journal of Korea Water Resources Association
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• v.32 no.1
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• pp.71-81
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• 1999

The objective of this study is to develop a model which can design an optimal pipe network system of least cost while satisfying all the design constraints including hydraulic constraints using a genetic algorithm technique. Hydraulic constraints interfaced with the simulation program(KYPIPE) checked feasible solution region. Genetic algorithm(GA) technique is a relatively new optimization technique. The GA is known as a very powerful search and optimization technique especially when solving nonlinear programming problems. The model developed in this study selects optimal pipe diameters in the form of commercial discrete sizes using the pipe diameters and the pumping powers as decision variables. The model not only determines the optimal diameters and pumping powers of pipe network system but also satisfies the discharge and pressure requirements at demanding nodes. The model has been applied to an imaginary and an existing pipe network systems. One system is adopted from journal papers which has been used as an example network by many other researchers. Comparison of the results shows compatibility of the model developed in this study. The model is also applied to a system in Goyang city in order to check the model applicability to finding of optimal pumping powers. It has been found that the developed model can be successfully applied to optimal design of pipe network systems in a relatively simple manner.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.103-108
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• 2004

In this paper, we present MIMIC(Millimeter-wave Monolithic Integrated Circuit) up-mixer with low conversion loss and low LO power for the V-band transmitter applications. The up-mixer was successfully integrated by using 0.1 ㎛ GaAs pseudomorphic HEMTs(PHEMTs) and coplanar waveguide (CPW) structures. The circuit is designed to operate at RF frequencies of 60.4 GHz, IF frequencies of 2.4 GHz, and LO frequencies of 58 GHz. The fabricated MIMIC up-mixer size is 2.3 mmxl.6 mm. The measured results show that the low conversion loss of 1.25 dB when input signal is -10.25 dBm at LO power of 5.4 dBm. The LO to RF isolation is 13.2 dB at 58 GHz. The fabricated V-band up-mixer represents lower LO input power and conversion loss characteristics than previous reported millimeter-wave up-mixers.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.38-47
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• 1997

A new weighing sensor for the automatic diameter control system of the crystal growth is developed in this study. This weighing sensor measures the frequency of the vibrating element which is lineally changing with respect to weight. The signal and the power of this system are transmitted without any physical contact, so that this sensor offers high accuracy and resolution. This system consists of a string, a sinusoidal wave generator, an automatic amplification adjusting circuit, signal transformers and a PCB. 4 kinds of programs are developed for checking DAC, weight calibration and controlling growth process. The measurements of the standard deviation and the resolution show $\pm0.10g$(measured at every second) and $5{\times}10^{-5}$, respectively, This weighing sensor is effective under high pres-sure of 200 atm, high temperature and vacuum condition. The weighing system can control the temperature in the accuracy of $\pm0.025^{\circ}C$ with the 'signal divider'. The optical quality single crystals of $(YGd)_3Sc_2Ga_3O_{12},\;Er-Y_3Sc_2Al_3O_{12},\;and\;Bi_{12}GeO_{20}$ have been grown by Czo-chralski method using this auto-diameter control system.

• Journal of Life Science
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• v.29 no.2
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• pp.231-238
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• 2019

This study evaluated the antioxidant activity of the extract and fractions of Alnus firma. Alnus firma had the highest total phenolic content ($452.80{\pm}7.01{\mu}g$ gallic acid equivalents/mg) in a methanol (MeOH) fraction and the highest total flavonoid content ($112.29{\pm}11.14{\mu}g$ rutin equivalents/mg) and antioxidant capacity ($936.23{\pm}0.07{\mu}g$ ${\alpha}$-tocopherol equivalents/mg) in an ethylacetate (EA) fraction. The antioxidant activities of various solvent extract fractions of Alnus firma were evaluated using various antioxidant assays, including ${\beta}$-carotene-linoleate assay, reducing power assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, metal chelating activity assay, superoxide anion radical scavenging assay, and lipid peroxidation inhibition assay using the ferric thiocyanate method. These activities were compared with those of ascorbic acid, butylated hydroxyanisole (BHA), gallic acid (GA), butylated hydroxytoluene (BHT), and ${\alpha}$-tocopherol. First, at a $250{\mu}g/ml$ concentration, the EA and MeOH fractions of A. firma showed 92.43% and 89.20% DPPH radical scavenging activity, respectively. Second, $50{\mu}g/ml$ of the EA fraction exhibited 72.49% superoxide anion radical scavenging activity, a little greater than the same dose of GA (60.88%). Finally, 0.5 and 1 mg/ml of the EA fraction showed 73.45% and 73.29% inhibition of peroxidation in the ${\beta}$-carotene-linoleic acid system, respectively. The decreasing order of reducing power was EA fraction > n-butanol (BuOH) fraction > dichloromethane (DCM) fraction > n-hexane (HX) fraction. The results obtained in the present study indicated that Alnus firma can be used as an easily accessible potential source of natural antioxidants.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1218-1230
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• 2021

Purpose To compare the per-patient diagnostic performance of simulated abbreviated MRI (AMRI) to that of conventional MRI (CMRI) with full-sequence dynamic gadoxetic acid (GA) enhancement for early-stage hepatocellular carcinoma (HCC) screening in high-risk patients. Materials and Methods A total of 201 consecutive patients at high-risk for HCC, who underwent 3T liver MRI, were included in this retrospective study. The AMRI protocol comprised T2-weighted imaging, hepatobiliary phase imaging after GA injection, and diffusion-weighted imaging. For each patient, two AMRI and CMRI image sets were independently reviewed by two radiologists. Inter-reader agreement was assessed using Cohen's kappa value. A composite reference standard was used to determine the diagnostic performance of each image set for each reader. Results A total of 93 HCCs were detected in 79 patients. The inter-reader agreement was almost perfect for both image sets (κ = 0.839, 0.948). In AMRI, the per-patient sensitivity and negative predictive values (NPV) were 94.9% and 96.4%, respectively. In CMRI, the per-patient sensitivity and NPV were 96.2% and 97.5%, respectively. Conclusion AMRI, using only three sequences, had a comparable diagnostic performance to CMRI in screening early-stage HCC. AMRI could be an alternative HCC screening tool for high-risk HCC patients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.965-970
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• 2005

In this paper, SPDT Tx/Rx MMIC switch applicable to IEEE 802.11a WLAN systems is designed and fabricated using a specific designed epitaxial layered pHEMT wafer and ETRI's $0.5{\mu}m$ pHEMT switch process. The SPDT switch exhibits a low insertion loss of 0.68dB, high isolation of 35.64dB, return loss of 13.4dB, power transfer capability of 25dBm, and 3rd order intercept point of 42dBm at frequency of 5.8GHz and control voltage of 0/-3V. The comparison of the measured performances with commercial products based on the GaAs pHEMT technology for low voltage operating at ${\pm}$ 3V/0V shows that the return loss is somewhat inferior to the commercial products and insertion loss is compatible with each other however, isolation characteristics are much better than in conventional chips. Based on these performances, we can conclude that the developed SPDT switch MMIC has an enough potential for IEEE802.11a standard 5 GHz-band wireless LAN applications.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.194-201
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• 2020

Latency and amplitude are the measurement parameters of mismatch negativity (MMN). The values of the parameters vary sensitively with the stimulus paradigm. A paradigm using the frequency difference of sounds for the MMN study is well known. This study obtained the reference values of the parameters in healthy young adults by performing the MMN study using the frequency paradigm. The authors recruited ten healthy adults. Their average age was 25.5 years; three were female, and seven were male. On the auditory paradigm for the MMN study, the frequency of sound was 1000 Hz for the standard stimulus, and 1032 Hz for the deviant stimulus. The mean values of latency and amplitude of MMN were 202 ms and 1.88 ㎶ at Fz, 207 ms, and 1.46 ㎶ at Cz, 212 ms, and 1.10 ㎶ at C3, and 214 ms and 1.45 ㎶ at C4. There was no correlation between the latency and amplitude of MMN. This study presented the reference values of the latency and amplitude of the MMN using a standard paradigm that is easy to apply. This information may make the MMN useful for clinical applications and basic research.