• 대한수학회논문집
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• 제36권4호
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• pp.817-827
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• 2021

In this paper, we prove that a diffeomorphism f on a normal almost contact 3-manifold M is a CRL-transformation if and only if M is an α-Sasakian manifold. Moreover, we show that a CR-loxodrome in an α-Sasakian 3-manifold is a pseudo-Hermitian magnetic curve with a strength $q={\tilde{r}}{\eta}({\gamma}^{\prime})=(r+{\alpha}-t){\eta}({\gamma}^{\prime})$ for constant 𝜂(𝛄'). A non-geodesic CR-loxodrome is a non-Legendre slant helix. Next, we prove that let M be an α-Sasakian 3-manifold such that (∇_YS)X = 0 for vector fields Y to be orthogonal to ξ, then the Ricci tensor 𝜌 satisfies 𝜌 = 2α²g. Moreover, using the CRL-transformation $\tilde{\nabla}^t$ we fine the pseudo-Hermitian curvature $\tilde{R}$, the pseudo-Ricci tensor $\tilde{\rho}$ and the torsion tensor field $\tilde{T}^t(\tilde{S}X,Y)$.

• 호남수학학술지
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• 제6권1호
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• pp.1-12
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• 1984

Let(X, $\Im$) be a probabilistic metric space with a t-norm. Common fixed point theorems and convergence theorems generalizing the results of Ćirić, Fisher, Sehgal, Istrătescu-Săcuiu and others are proved for three mappings P,S,T on X satisfying $F_{Pu, Pv}(qx){\geq}min\left{F_{Su,Tv}(x),F_{Pu,Su}(x),F_{Pv,Tv}(x),F_{Pu,Tv}(2x),F_{Pv,Su}(2x)\right}$ for every $u, v {\in}X$, all x>0 and some $q{\in}(0, 1)$. One of the main results is extended to uniform spaces. Mathematics Subject Classification (1980): 54H25.

• 수산경영론집
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• 제22권2호
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• pp.75-99
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• 1991

A quantitative analysis was carried out to monitor the commercial yield level of walleye pollock Theragra chalcogramma in the east coast of Korea, based on available data on catch and fishing effort, catch per unit of effort including fish prices from 1911 to 1988, using a traditional yield model. The results from the quantitative assessment were based to estimate maximum economic yield (MEY) and optimal fishing effort (E-opt) at MEY. On the other hand, interaction aspects between danish seine fishery and trawl fishery mainly targeting walleye pollock in the east coast of Korea were studied to predict optimal situation in fishing effort level from economic point of view which gives the most benefits to the two fisheries. Total production of walleye pollock in 1911 when its catch record was begun for the first time was about 12, 000 metric tons(M/T), and then the catch trend maintained nearly at the level of 50, 000 M/T per annum, showing a decreasing trend until 1930. The highest production from historical data base on walleye pollock fishery statistics was from the years in 1939 and 1940, about 270, 000 M/T and 26, 000 M/T, respectively. No production of the fish species was recorded during the years from 1943 to 1947, and from 1949 to 1951. From 1952 onwards annual production was only available from the southern part of 38$^{\circ}$N in the east coast. During two decades from 1952 to 1970, the production had sustained about less than 30, 000 M/T every year. Annual production showed an increasing trend from 1971, reaching a maximum level of approximately 162, 000 M/T in 1981. Afterwards, it has deceased sharply year after year and amounted to 180, 000 M/T in 1988. The catch composition of walleye pollock for different fishery segments during 1970~1988 showed that more than 70% of the total catch was from danish seine fishery until 1977 but from 1978 onwards, the catch proportion did not differ from one another, accounting for the nearly same proportion. Catch per unit of effort (CPUE) for both danish seine fishery and trawl fishery maintained a decline tendency after 1977 when the values of CPUE were at level of 800 kg/haul for the former fishery and 1, 300 kg/haul for the latter fishery, respectively. CPUEs of gillnet fishery during 1980~1983 increased to about 3.5 times as high value as in the years, 1970~1979 and during 1987~1988 it decreased again to the level of the years, 1970~1978. The bottom longline fishery's CPUE wa at a very low level (20 kg/basket) through the whole study years, with exception of the value (60 kg/basket) in 1980. Fishing grounds of walleye pollock in the east coast of Korea showed a very limited distribution range. Danish seine fishery concentrated fishing around the coastal areas of Sokcho and Jumunjin during January~February and October~December. Distributions of fishing grounds of trawl fishery were the areas along the coastal regions in the central part of the east coast. Gillnet and bottom longline fisheries fished walleye pollock mainly in the areas of around Sokcho and Jumunjin during January~February and December. Relationship between CPUEs' values from danish seine fishery and trawl fishery was used to standardize fishing effort to apply to surplus production model for estimating maximum sustainable yield (MSY) and optimum fish effort (F-opt) at MSY. The results suggested a MSY of 114, 000 M/T with an estimated F-opt of 173, 000 hauls per year. Based on the estimates of MSY and F-opt, MEY was estimated to be about 94, 000 M/T with a range of 81, 000 to 103, 000 M/T and E-opt 100, 000 hauls per year with a range of 80, 000 to 120, 000 hauls. The estimated values of MEY and E-opt corresponded to 82% of MSY and 58% of F-opt, respectively. An optimal situation in the fishing effort level, which can envisage either simultaneously maximum yield or maximum benefit for both danish seine fishery and trawl fishery, was determined from relationship between revenue and cost of running the fleet : the optimal fishing effort of danish seine fishery was about 52, 000 hauls per year, corresponding to 50 danish seiners and 27, 000 hauls per year which is equal nearly to 36 trawlers, respectively. It was anticipated that the net income from sustainable yield estimated from the respective optimal fishing effort of the two fisheries will be about 3, 800 million won for danish seine fishery and 1, 000 million won for trawl fishery.

• 대한전자공학회논문지SD
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• 제42권9호
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• pp.1-8
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• 2005

최근 Mobile용 RF ICs 적용을 위한 RF CMOS 기술과 함께 핵심 기술로 SiGe Heterojunction Bipolar Transistor (HBT) 소자 개발의 중요성이 증대되고 있다. 본 논문은 현재 5GHz 동작 수준의 RF제품에서 주로 사용되는 기술인 $0.35\{mu}m$ 설계 Rule을 적용하여 $f_{max}$ 50GHz에서 동작하는 SiGe BiCMOS 기술 개발에 대한 내용을 논의한다. 본 SiGe HBT에 사용하는 에피막 성장 기술은 Trapezoidal Ge base profile 및 non-selective 방식이고, 에미터 RTA 조건 및 SiGe HBT base에 대한 Vertical Profile 최적화를 수행하였다. hFE 100, $f_{T}\;45GHz,\;NF_{min}\;0.8dB$ 수준으로 우수한 특성 및 기술 경쟁력을 갖는 SiGe BiCMOS 공정 개발 및 양산 기술을 확보하였다. 또한, 기존의 0.35um설계 Rule공정 target떼 부합되는 CMOS소자를 포함시켰으며, RF용 Passive소자로 높은 Q값을 갖는 MIM capacitor(1pF, Q>80), Inductor(2nH $Q\~$l2.5)를 제공하였다

• BMB Reports
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• 제31권2호
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• pp.135-138
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• 1998

A previous study on a yeast protein tyrosine phosphatase, YPTP1, using synthetic phosphotyrosine-containing peptides with various sequences as substrates revealed that DADEpYDA exhibits high affinity ($K_m=4{\mu}M$) toward the enzyme. A modified version of this peptide, GDADEpmFDA, immobilized on a resin, was used in this study as an affinity ligand for the purification of YPTP1. Phosphonomethyl-phenylalanine (pmF) was used as a nonhydrolyzable analog of the phosphotyrosine (pY) residue, with properties similar to pY. A protected form of pmF, $Fmoc-pmF(^{t}Bu)_{2}-OH$, was chemically synthesized and introduced during solid-phase peptide sythesis. YPTP1 was onrexpressed in an E. coli strain carrying a plasmid pT7-7-ptpl. Affinity chromatography of the crude lysate afforded PTPI (39 kDa) of about 50% purity.

• ETRI Journal
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• 제36권5호
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• pp.772-782
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• 2014

Two-microphone binary mask speech enhancement (2mBMSE) has been of particular interest in recent literature and has shown promising results. Current 2mBMSE systems rely on spatial cues of speech and noise sources. Although these cues are helpful for directional noise sources, they lose their efficiency in diffuse noise fields. We propose a new system that is effective in both directional and diffuse noise conditions. The system exploits two features. The first determines whether a given time-frequency (T-F) unit of the input spectrum is dominated by a diffuse or directional source. A diffuse signal is certainly a noise signal, but a directional signal could correspond to a noise or speech source. The second feature discriminates between T-F units dominated by speech or directional noise signals. Speech enhancement is performed using a binary mask, calculated based on the proposed features. In both directional and diffuse noise fields, the proposed system segregates speech T-F units with hit rates above 85%. It outperforms previous solutions in terms of signal-to-noise ratio and perceptual evaluation of speech quality improvement, especially in diffuse noise conditions.

• Clinical and Experimental Pediatrics
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• 제63권3호
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• pp.110-114
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• 2020

Background: Subclinical hypothyroidism (SH) is a common condition in obese children. However, its effect on glucose and lipid metabolism in obese children remains controversial. Purpose: The present study aimed to investigate the association between SH and metabolic parameters. Methods: A total of 215 obese children and adolescents aged 6-18 years were included in this retrospective cross-sectional study. The patients' anthropometric measurements such as thyrotropin (TSH), free thyroxine (fT4), fasting plasma glucose, and insulin levels, as well as homeostasis model assessment for insulin resistance (HOMA-IR) index, and lipid profiles were evaluated. The patients were allocated to the SH group (fT4 normal, TSH 5-10 mIU/L) (n=77) or the control group (fT4 normal, TSH<5 mIU/L) (n=138). The glucose and lipid metabolisms of the 2 groups were compared. Results: SH was identified in 77 of 215 patients (36%). Mean body mass index was similar in both groups. The mean serum insulin, HOMA-IR, and triglyceride (TG) levels were higher and the mean high-density lipoprotein cholesterol level was lower in the SH group than in the control group (P=0.007, P=0.004, P=0.01, and P=0.02, respectively). A positive correlation was observed between TSH level and insulin level, HOMA-IR, and TG level. Conclusion: SH was identified in some of the obese children and adolescents. A clear association was observed between SH, insulin resistance, and dyslipidemia in obese children.

• 충청수학회지
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• 제29권3호
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• pp.453-464
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• 2016

In this paper, we investigate the solution of the following functional inequality $$N(f(x)+f(y)+f(z),t){\geq}N(f(x+y+z),mt)$$ for some fixed real number m with $\frac{1}{3}$ < m ${\leq}$ 1 and using the fixed point method, we prove the generalized Hyers-Ulam stability for it in fuzzy Banach spaces.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.1011-1018
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• 2011

Aflatoxin-contaminated feed cause mortality, suppression of the immune system, reduced growth rates and losses in feed efficiency. This research study was planned to investigate the immunomodulatory and growth promoting effect of milk thistle as feed additive against aflatoxin $B_1$ in broiler chicks at NWFP Agricultural University Peshawar, Pakistan. Two hundred and forty (240) day old broilers chicks were randomly assigned into four major groups AfF, aflatoxin free feed; Aflatoxin $B_1$ was present in the feed at the levels of 80-520 ${\mu}g/kg$ of the feed in the remaining three groups. Aflatoxin contaminated feed was provided for 5 weeks. Group AfB was supplemented with toxin binder "Mycoad" at 3 g/kg of feed and group AfT was supplemented with milk thistle at10 g/kg of feed. Each group was further sub divided into two sub-groups, vaccinated against ND (Newcastle disease), IB (Infectious bronchitis) and IBD (Infectious bursal diseases) according to recommended schedule of vaccination or non vaccinated. Each sub group carried three replicates with 10 chicks per replicate. Chicks were reared in pens in an open sided house. Supplementary heat was provided to all the chicks during brooding period. Mean body weight gain and dressing percentage were significantly (p<0.05) higher in group AfF, followed by AfT, AfB and Af. Weight gain and dressing percentage was the same in group AfB and AfT, while it was significantly lower in group Af. Feed intake, breast, thigh and leg weight were found significantly (p<0.05) higher in group AfF, followed by AfB, AfT and Af. Significantly lower (better) FCR value was recorded in group AfT. Water intake was significantly (p<0.05) higher in group AfT and AfF as compared to other groups. Mortality was significantly (p<0.05) higher in group Af. Mean bursa and thymus weights were found significantly (p<0.05) higher in group AfF, AfB and AfT followed by Af, while higher spleen weight was recorded in group AfT. Mean antibody titer against ND, IB and IBD was significantly (p<0.05) higher in group AfT, as compared to other groups. It is concluded that milk thistle at 10 g/kg of feed could effectively be utilized as immunostimulant and growth promotant in the presence of immunosuppressant aflatoxin $B_1$ in the feed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.357-362
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• 2006

OLEDs are becoming established as a commercially viable flat panel display technology of choice of the $21^{st}$ century because of its lightweight, fast response time, lower thickness than LCD's and potentially low cost (1-2). For the OLEDs to function effectively, highly thermally stable materials, which offer high efficiency and long operational lifetimes are required. To achieve long lifetime, highly stable charge (both holes and electrons) transporters are essential. OLED-T provides these materials as well as fluorescent and phosphorescent dopants. This paper reports a unique patented hole injector (E9363) and an electron transporter (E246) that increases the lifetime and efficiency and reduces operating voltage. Further, an electron injector, EEI-101, which evaporates at a very low temperature of $300^{\circ}C$ as opposed to the conventional LiF, which requires $580^{\circ}C$, is also presented.