• Kyungpook Mathematical Journal
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• v.19 no.2
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• pp.241-243
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• 1979

• The Magazine of the IEIE
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• v.5 no.1
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• pp.19-23
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• 1978

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.2 s.3
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• pp.65-72
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• 2003

In this work a 6-stage hybrid power amplifier which can be used for the wireless communication systems for MMC(hficrowave Micro Cell) and ITS wireless communication system is designed and fabricated. Ihe power amplifier's each stages was fabricated Hetero-junction Power FET of bare chip type and an alumina substrate with $\varepsilon_{r}$=9.9 and 15-mil thickness. The measured results of power amplifier module showed 33.2$\~$36.5 dB small signal gain, 33.0$\~$34.0 dBm output power at forward frequency (17.6 GHa $\~$ 17.9 CHz) and 36.0$\~$37.0 dB small signal gain, 33.0$\~$34.5 dBm output power at reverse frequency (19.0 GHz $\~$19.2GHz).

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.9-19
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• 2001

Microstructure and phase transformation of Ti-Ni-Cu alloy powders produced by using attrition milling method were studied. Mixed powders of Ti-(50-X)Ni-XCu ($X=0{\sim}20$ at%) in composition range were mechanically alloyed for maximum 20 hours by using SUS 1/4" ball in argon atmosphere. Ball to powder ratio was 50: 1 and impeller speed was 350rpm. Mechanically alloyed with attrition millimg method. powder was heat treated at the temperature up to $850^{\circ}C$ for 1 hour in the $10^{-6}$ torr vacuum. Ti-Ni-Cu alloy powders have been fabricated by attrition milling method. and then phase transformation behaviours and microstructual properties of the alloy powders were investigated to assist in improving the the high damping capacity of Ti-Ni-Cu shape memory alloy powders. The results obtained are as follows: 1. After heat treating of fully mechanically alloyed powder at $850^{\circ}C$ for 1hour. most of the B2 and B 19' phases was formed and $TiNi_3$ were coexisted. 2. The B 19' martensite were formed in Ti-Ni-Cu alloy powders whose Cu-content is less than 5a/o. where as the B19 martensite in those whose Cu-content is more than 10at%. 3. The powders of as-milled Ti-Ni-Cu alloys whose Cu-contents is less than 5at% are amorphous. whereas those of as-milled Ti-Ni-Cu alloys whose Cu-content is more than 10at% are crystalline. This means that Cu addition tends to suppress amorphization of Ti-Ni alloy powders.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1025-1031
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• 2019

This study proposes a PCS that enables efficient operation of seawater pumps for ships by implementing ML-based algorithms. Seawater temperature, RPM and power consumption data are acquired from two ships with PCS, analyzed with regression analysis method, and new algorithms are presented. Using the algorithms presented, Ship A saved about 36% compared to the PCS application, and ML-based algorithms in certain sea temperatures of 19 to 27 degrees Celsius and above 32 degrees Celsius were about 1% lower than Ship A's PCS. Ship B saved about 50% compared to PCS not applied, and about 2% more than Ship B's PCS in waters above $19^{\circ}C$, a specified sea temperature. The derived data can be used to suggest the optimum pump speed and sea route. In addition, the trend of acquired data can be used to infer the performance of the pump or the timing of elimination of the MGPS when efficiency becomes poor.

• Hip & pelvis
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• v.35 no.4
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• pp.253-258
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• 2023

Purpose: To figure out how complete control of family visits to prevent infection of coronavirus disease 2019 (COVID-19) affected the activity recovery of hip fracture patients admitted to nursing hospitals. Materials and Methods: Eighty-one patients with hip surgery in the two years prior to COVID-19 pandemic were classified as Group A, and 103 patients in the next two years were designated as Group B. The subjects' walking ability was evaluated by using the modified Koval index (MKI). In order to analyze the impact of the family visit control to the subjects, each group was classified into two different groups: (1) inpatients group who admitted to nursing hospitals and (2) home-treated patients. Additionally, statistical elements were processed in consideration of other factors that may affect the results of the experiment. Results: The MKI evaluated at 6 months postoperative was 3.31±1.79 in Group A and 2.77±1.91 in Group B, and it was meaningfully low after the pandemic (P=0.04). There was significantly low among both of Group A 2.74±1.76 and Group B 1.93±1.81 after the pandemic (P=0.03) among those treated at the nursing hospital. The rate of deterioration of the MKI was 35 (43.2%) in Group A and 57 (55.3%) in Group B, which increased by 12.1% after the pandemic. Conclusion: The pandemic had a negative effect on the recovery of postoperative activities of elderly hip fracture patients who admitted to nursing hospitals when family access was completely restricted to prevent infection.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.12
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• pp.547-552
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• 2002

In this paper, the path loss in domestic terrain environments for IMT-2000 are measured and considered. Domestic terrain environments are classified and received power is measured at 1.9201GHz. In addition, the Path loss is calculated with consideration of the radiation pattern of antennas based on the results of measurement. For the consideration of path loss in domestic terrain environments, each path loss are fitted with the same slope of a reference model as "COST-231 HATA Urban Model", and then both are compared. As a result, all of the path loss in domestic terrain environments are lower than the path loss of a reference model as "COST-231 HATA Urban Model". We found that a difference of path loss in domestic terrain environments and a reference model is 5dB in urban, 8dB in sparse urban, 12dll in dense suburban, 13dB in suburban, 19dB in sparse suburban, and 29dB in road.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.209-215
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• 2010

This study is an endeavor to evaluate the risk assessment of hazardous(aflatoxin $B_1$) in medicines from oriental medical prescription which are circulated much recently. For that, twelve globular and granule types, seven liquid types of herbal medicine were bought to compare and analyze the content of aflatoxin aflatoxin B_1), which are harmful to human body. Woo Hwang Cheong Sim Hwan of Aflatoxin $B_1$ concentration lower than the standard accepted by all the products have been detected, B company(tradition) is the concentration of $1.24\;{\mu}g/kg$, C company $1.04\;{\mu}g/kg$, A company(tradition) and B company did not detect. And the general pill of aflatoxin B1 concentration lower than the standard accepted by all the products have been detected, S-1 is the concentration of $1.8\;{\mu}g/kg$, S-2 of $1.04\;{\mu}g/kg$, S-3 of $0.88\;{\mu}g/kg$, S-4 of $9.32\l\;{\mu}g/kg$, S-6 of $7.8\;{\mu}g/kg$, S-5 did not detect. All the products eundan allowed in the concentration of aflatoxin $B_1$ levels were lower than detection, D company of $0.96\;{\mu}g/kg$, E company concentration was not detected. The liquid product of aflatoxin $B_1$ concentration was found liwer than the standard accepted by all the product, L-3 concentration of $0.8\;{\mu}g/kg$, K-4 was detected in the $1.16\;{\mu}g/kg$, L-1 and L-2 is not detected, L-5 concentration of $15\;{\mu}g/kg$, L-7 is detected as $1.08\;{\mu}g/kg$ and, L-6 was not detected.

• Clinics in Shoulder and Elbow
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• v.19 no.2
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• pp.73-77
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• 2016

Background: The first purpose of this study is to compare the clinical and radiological outcomes of surgical treatment for displaced midshaft clavicle fracture (Robinson type 2B1 vs. 2B2) with 3.5-mm low profile clavicular locking compression plate. The second purpose is to evaluate the difference of the results depending on the presence of accompanying injuries. Methods: Forty-nine patients who underwent an operation for the fractures were reviewed retrospectively. Fracture patterns were classified according to group 2B1 and 2B2 using Robinson's classification. For radiological outcome, time to union after operation was evaluated and for clinical outcome, American Shoulder and Elbow Society (ASES) score, University of California in Los Angeles (UCLA) score, visual analogue scale (VAS), and range of motion (ROM) were evaluated from preoperative period to last follow-up period. Results: The mean time for union was not significantly different in the 2B1 group and 2B2 group (p=0.062). No statistically significant difference in ASES score, UCLA score, and VAS was observed between 2B1 and 2B2 (p=0.619, p=0.896, p=0.856, respectively). In ROM, significant higher mean forward flexion and abduction was observed in 2B2 (p=0.025, p=0.017, respectively) and there was no difference in external rotation and external rotation at shoulder $90^{\circ}$ abduction position (p=0.130, p=0.180, respectively). There was no significant difference in clinical outcomes according to the accompanying injuries. Conclusions: There was no difference in clinical and radiological outcome between Robinson 2B1 and 2B2 type fracture after the operation. Accompanying injuries may not affect the clinical result of displaced midshaft clavicle fractures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.395-402
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• 2001

A fusant FG-21 was selected on the basis of higher ${\gamma}-GTP$ activity following fusion process between SM-2 and SM-10 of Bacillus subtilis mutants. ${\gamma}-GTP$ activity of the mutant FG-21 was increased up to 612 U/mL when grown for 36 hr at $37^{\circ}C$ in culture media containing 1% glycerol 1% glycerol, 1% peptone, 0.1% citric acid, 5 mM $K_2HPO_4$, 1 mM $FeCl_3$, 1 mM $MgCl_2$, 1 mM $NH_4Cl$, pH 7.0. In fusnat FG-21, the ratio of protein to total sugar contents for biopolymer A was 38 to 59. for biopolymer B from parental strains it was 19 to 78. Fructose contents determined by HPLC were $573.7\;\mu\textrm{g}/mg\;and\;764.4\;\mu\textrm{g}/mg$ for biopolymer A and B, respectively. And glutamic acid content were $163.7\;\mu\textrm{g}/mg\;and\;94.6\;\mu\textrm{g}/mg$ for biopolymer A and B, respectively. In fusant FG-21, the ratio of fructose to glutamic acid contents for biopolymer A was 78 to 22. For biopolymer B from parental strains it was 89 to 11.