• Journal of the Korean Mathematical Society
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• v.45 no.4
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• pp.903-921
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• 2008

A continuous linear operator $T\;:\;X{\rightarrow}X$ is called hypercyclic if there exists an $x\;{\in}\;X$ such that the orbit ${T^nx}_{n{\geq}0}$ is dense. We consider the problem: given an operator $T\;:\;X{\rightarrow}X$, hypercyclic or not, is the restriction $T|y$ to some closed invariant subspace $y{\subset}X$ hypercyclic? In particular, it is well-known that any non-constant partial differential operator p(D) on $H({\mathbb{C}}^d)$ (entire functions) is hypercyclic. Now, if q(D) is another such operator, p(D) maps ker q(D) invariantly (by commutativity), and we obtain a necessary and sufficient condition on p and q in order that the restriction p(D) : ker q(D) $\rightarrow$ ker q(D) is hypercyclic. We also study hypercyclicity for other types of operators on subspaces of $H({\mathbb{C}}^d)$.

• Journal of the Korean Mathematical Society
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• v.44 no.4
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• pp.863-872
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• 2007

Let D be an integral domain with quotient field K, A a nonempty set of height-one maximal t-ideals of D, F$({\Lambda})={I{\subseteq}D|I$ is an ideal of D such that $I{\subseteq}P$ for all $P{\in}A}$, and $D_F({\Lambda})={x{\in}K|xA{\subseteq}D$ for some $A{\in}F({\Lambda})}$. In this paper, we prove that if each $P{\in}A$ is the radical of a finite type v-ideal (resp., a principal ideal), then $D_{F({\Lambda})}$ is a weakly Krull domain (resp., generalized weakly factorial domain) if and only if the intersection $D_{F({\Lambda})}={\cap}_{P{\in}A}D_P$ has finite character, if and only if $F({\Lambda})$ is a t-splitting set of ideals, if and only if $F({\Lambda})$ is v-finite.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.37-44
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• 1996

The present study was conducted to investigate the role of thyroid hormones in the regulation of gene expression of calbindin-$D_{28k}$ (CaBP-D28K) in the chicken. By employing slot blot and RIA analyses, levels of CABP-D28K mRNA and CaBP-D28K protein in the intestine, kidney, cerebellum and liver were measured 6 and 12 h after i.m. injection of 1, 25-dihydroxyvitamin $D_3$ [1, 25 $(OH)_2D_3$; 250 ng/chick] and 3, 5, 3'-triiodothyronine ($T_3$; 500 ng/chick) in one-day-old chicks. The abundant messages of CaBP-D28K mRNA were detected in the intestine, kidney and cerebellum while there was little message in the liver. After 1, 25 $(OH)_2D_3$ treatment (6 + 12 hours), levels of CaBP-D28K mRNA increased in the intestine, but there was no change in the mRNA levels in the kidney and cerebellum. Although $T_3$ alone had no effect on CaBP-D28K mRNA levels, simultaneous administration of $T_3$ enhanced the 1, 25 $(OH)_2D_3$ effect of levels of CaBP-D28K mRNA in the intestine both 6 and 12 h post-treatment, and in the kidney 12 h post-treatment. At a protein level, co-treatment with 1, 25 $(OH)_2D_3$ and $T_3$ elicited a significant increase in CaBP-D28K expression in the intestine 12 h post-treatment, as compared to treatment with only 1, 25 $(OH)_2D_3$, whereas no differences were observed in the CaBP-D28K protein levels in the kidney and cerebellum. These results suggest that thyroid hormones may play a synergistic role with 1, 25 $(OH)_2D_3$ for CaBP-D28K gene expression in the intestine and kidney in chicks.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.1
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• pp.50-55
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• 1992

Piezoelectric Buzzer which has been generally used requires about 30kV/cm poling process and has the aging effects. In this study, 0.85 PZN - 0.10 BT - 0.05 PT system ceramics with additives of 0 - 2 wt% YS12TOS13T were fabricated and investigated on electromechanical coupling coefficient(kS1pT), electric field induced charge coefficient(dS131T), and sound level. As the results, in the 0.4 wt% YS12TOS13T added composition ceramics compared with the basic, kS1pT was increased from 0.355 to 0.39 and induced piezoelectric d constant increased from 204 to 220 x 10S0-12T (C/N) and sound level of electrostrictive Buzzer has the highest value of 71.5 dB under 8kV/cm bias electric field.

• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.165-173
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• 1992

The present study was carried out to investigate the effects of dopaminergic drugs and the role of specific dopamine(DA) receptors on the release of TSH, $T_4$ and $T_3$. Serum TSH levels (cold-induced, $4{^{\circ}C}$) were determined using RIA(radioimmunoassay) at 30 min after administration of dopamine agonists and antagonists. Serum $T_4$ and $T_3$ levels were detected after these dopaminergic drugs were administered subcutaneously twice a day for a week. The results of the study are summarized as follows : Apomorphine, a nonspecific DA receptor agonist, produced a dose-depedent decrease in serum TSH, $T_4$ and $T_3$ levels. However, only low doses (0.3, 1.0mg/kg) of SKF38393, a specific $D_1$-receptor agonist, produced a decrease in serum lelvels of TSH. I,Y171555, a specific $D_2$-receptor agonist, produced a dose dependent decrease in serum TSH, $T_4$ and $T_3$ levels. However, SCH23390, a specific $D_1$-receptor antagonist, produced a decrease except in serum T levels which were increased dose dependently. High doses (1.0, 3.0mg/kg) of sulpiride, a specific $D_2$-receptor antagonist, made a increase in the serum levels of TSH and $T_3$. The effects of dopaminergic drugs in serum TSH and $T_4$ levels was potentiated by the pretreatment of apomorphine. The overall results of this study suggest that the regulation of TSH, $T_4$ and $T_3$ secretion were mediated via specific $D_1$ and $D_2$ receptor.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.171-176
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• 2008

Animal welfare advocates, claim that the induced molting by fasting be avoided. This study was conducted to evaluate the effect of molting induced by various feeding methods on productivity and egg quality in laying hens. We used 400 flocks of 60-week-old leghorn laying hens in four treatments(five replicates of 20 hens each): fasting method (C), feeding single corn grain diet (T1), feeding single wheat bran diet (T2) and feeding single alfalfa meal diet (T3). As the result of the experiment, egg production and daily egg mass significantly decreased only in T1 compared with the control during the $1{\sim}4th$ week after the secondary egg laying (P<0.05). Although the amount of feed intake was significantly less in T1 group during the $1{\sim}4th$ week compared to the control, no significant difference was detected during the total period (P>0.05). In addition, no significant difference of feed conversion was observed between treatment groups. In terms of egg quality, the egg shell thickness was significantly improved in T1 group than the control group by feeding only corn at the 10th and 14th week after the secondary egg laying (P<0.05), but the significant decrease was observed at the corn (T1) and wheat bran (T2) fed treatment groups than the control group at the 26th week of the experiment (P<0.05). The eggshell strength and haugh unit did not show any difference by the molting methods. Egg yolk color was significantly decreased in T1 and T2 group than the control group at the 6th week (P<0.05). However, T1 and T2 group resulted to show significantly high egg yolk color at the 18th week of the experiment (P<0.05). As the result of the experiment, no large difference was observed in the productivity by the feeding molting method and by the fasting induced molting method. In addition, the single diet fed feeding induced molting method by using alfalfa revealed to show more satisfactory trend than the corn or wheat bran single diet fed feeding induced molting methods even if no statistically significant difference was found in terms of egg productivity.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2691-2696
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• 2009

Effects of representative group II and transition metal ions on the stability of the $poly(dA){\cdot}[poly(dT)]_2$ triplex were investigated by the van’t Hoff plot constructed from a thermal melting curve. The transition, $poly(dA){\cdot}[poly(dT)]_2\;{\rightarrow}\;poly(dA){\cdot}poly(dT)\;+\;poly(dT)$, was non-spontaneous with a positive Gibb’s free energy, endothermic (${\Delta}H^{\circ}$ > 0), and had a favorable entropy change (${\Delta}S^{\circ}$ > 0), as seen from the negative slope and positive y-intercept in the van’t Hoff plot. Therefore, the transition is driven by entropy change. The $Mg^{2+}$ ion was the most effective at stabilization of the triplex, with the effect decreasing in the order of $Mg^{2+}\;>\;Ca^{2+}\;>\;Sr^{2+}\;>\;Ba^{2+}$. A similar stabilization effect was found for the duplex to single strand transition: $poly(dA){\cdot}poly(dT)\;+\;poly(dT)\;→\;poly(dA)\;+\;2poly(dT)$, with a larger positive free energy. The transition metal ions, namely $Ni_{2+},\;Cu_{2+},\;and\;Zn_{2+}$, did not exhibit any effect on triplex stabilization, while showing little effect on duplex stabilization. The different effects on triplex stabilization between group II metal ions and the transition metal ions may be attributed to their difference in binding to DNA; transition metals are known to coordinate with DNA components, including phosphate groups, while group II metal ions conceivably bind DNA via electrostatic interactions. The $Cd_{2+}$ ion was an exception, effectively stabilizing the triplex and melting temperature of the third strand dissociation was higher than that observed in the presence of $Mg_{2+}$, even though it is in the same group with $Zn_{2+}$. The detailed behavior of the $Cd_{2+}$ ion is currently under investigation.

• Journal of Mushroom
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• v.16 no.4
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• pp.257-262
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• 2018

The aim of this study was to re-use spent mushroom substrate (SMS) with increased total nitrogen (T-N) and amino acid content and reduce the amount of cottonseed meal used as nutrient supplement in Pleurotus ostreatus cultivation. Bacteria used for improvement of the T-N content were GM20-4(Bacillus sp.) and Rhodobacter sphaeroides (RS). GM20-4 was isolated from the SMS of P. ostreatus and RS was obtained from Gwangjusi agricultural technology center. SMS in T1, T2, and T3 was reused as substrate after drying and the T-N content of dried SMS (D-SMS) was increased by 0.34% by treatment with the bacteria. T1 with 8% D-SMS and T2 with 18% D-SMS had higher rates of primordia formation compared with T3 and the control. The biological efficiency of the control and of treatment with 8%, 18%, and 26% D-SMS was 110%, 114%, 112%, and 79%, respectively. Considering the economic cost, yield, and biological efficiency, T2 with 18% D-SMS as the culture substrate for P. ostreatus was shown to be the most effective for cultivation.

• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.131-137
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• 2010

Background: Montgomery T-tube is widely used to maintain airway in many cases. Market-available tubes are not always fit to the trachea of each patient and need some modification such as trimming. Complications do happen in prolonged use like tracheostomy tubes. To overcome above limitations, we designed custom-made T-tube using CT data with the aid of 3D reconstruction software. Material and Method: Boundaries were extracted from neck CT data of normal person and processed by surface rendering methods. Real laryngotracheal model and tracheal inner surface-mimicking tube model were made with plaster and rubber. The main tube was designed by accumulation of circles or simple closed curves made from boundaries. Stomal tube was made by accumulation of squares due to limitation of software. Measurement data of tracheal lumen were used to custom-made T-tubes. Tracheal lumen residing portion (vertical limb) was made like circular cylinder or simple closed curved cylinder. Stomal portion (horizontal limb) was designed like square cylinder. Results: Custom made T-tube with cylindric vertical limb and horizontal limb of square cylinder was designed. Conclusion: CT data was helpful in making custom made T-tube with 3D reconstruction technique. If suitable materials are available, commercial T-tube can be printed out from 3D printers.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.13 no.2
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• pp.1-4
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• 1977

The author determined the relationship between the hauling veloicty and the hydrodynamic resistance of the sablefish pot shaped conic frustum like, and induced the formulae to determine the diameter of the main line and the net horse power of the pot hauler. The results are summarized as follows: 1. The maximum hydrodynamic resistance (with its weight in water) of the pot T(kg), when the bottom webbing is covered by a cloth to imitate the catches are scattered on the bottom, is eatimated as $$ T=120v^{1.1} (0.3{\leqq}v{\leqq}0.8) $$ where v denotes the hauling velocity of the pot in m/sec. 2. When P. P. 3 strand rope is used as main line, the diameter d(mm)is recommended to satisfy the formula $$ d=72 \frac{D}{H} V^{1.1} where H denotes the depth of the fishing ground and D the intervals of the pots linked to the main in m respectively. 3. The pot hauler must displace the net horse power p(ps) of $$ P= \frac{75}{120} \frac{D}{H} v^{2.1}$$