• 대한치과교정학회지
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• 제31권4호
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• pp.403-414
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• 2001

본 연구의 목적은 modified Teuscher Appliance(MTA)와 bionator를 이용하여 치료한 II급 1류 부정교합 환자의 치료전후 측모 두부방사선계측사진을 비교분석함으로써 두 장치 사이의 치료효과에 대한 차이를 밝혀내어 성장하는 II급 1류 부정교합을 가진 환자들의 치료에 도움을 얻는데 있다. MTA 및 bionator를 이용하여 성공적으로 치료한 혼합치열기 II급 1류 부정교합 환자 20명의 치료전과 치료후 두부방사선계측사진의 계측항목을 계측한 후, 두군 사이에 나타나는 치료효과의 차이를 알아보기 위해 치료전후 항목의 차이를 구하였다. 이 항목들에 대해 t-test를 시행하여 다음과 같은 결과를 얻었다. 1. 양군 사이에 통계적인 유의성이 나타난 선계측 항목으로 U1 to FH, U1 to PP, U6, to PP, U6 to FH, Ar-Pog, ramus height(S-Go), L1 to A-Pog, L1 to facial plane 등이 있었다(p<0.05). 2. 양군 사이에 통계적 유의성이 크게 나타난 각도계측 항목으로 SNB, SNA, FABA(FH to AB plane angle), APDI 등이 있었다(p<0.05). 3. 양군 사이에 성장양상을 나타내는 Facial height ratio, $Bj\ddot{o}rk$ sum, FMA, SN-MP angle 등은 통계적인 유의성을 보이지 않았다(p>0.05). 이 상의 결과를 통해 II급 1류 부정 교합을 치료하는데 있어 bionator는 주로 하악골과 하악치열에 상대적으로 효과가 크게 나타나며, MTA는 상악골과 상악치열에 더 큰 효과가 나타남을 알 수 있었다. 이런 결과는 두 장치가 각기 다른 치료기전을 가지고 있으므로, 다른 종류의 부정교합에 적용해야 한다는 것을 가리킨다.

• Animal Bioscience
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• 제34권11호
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• pp.1749-1756
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• 2021

Objective: Microminipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs. Methods: The occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters. Results: The incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different. Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

• 한국항행학회논문지
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• 제10권2호
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• pp.167-172
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• 2006

본 논문에서는 항공관제용 UHF대역 25W 전력 증폭기를 설계 및 제작하였다. 전력 증폭기는 구동단, 전력 증폭단 및 제어부로 구성되었으며, 광대역 동작을 위하여 부궤환 회로 및 동축선로 발룬이 사용되었다. 선형성 및 효율성이 우수한 VDMOS를 전력소자로 사용하였으며, AB급 바이어스에서 push-pull 증폭을 하도록 설계하였다. 설계된 전력 증폭기는 게이트단에 음성 신호가 인가되었을 때 안정적인 AM 변조 특성을 나타내었으며, 상용 항공관제용 무선 송신기의 출력 사양을 만족하도록 설계 및 구현되었다.

• 대한전자공학회논문지TC
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• 제44권2호
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• pp.76-80
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• 2007

본 논문에서는 이중 바이어스 조절과 PBG 구조를 이용하여 Doherty 증폭기의 효율과 선형성을 개선하였다. PBG 구조를 출력 정합회로에 구현하였으며, 이중 바이어스 조절을 Carrier Amplifier에 적용하여 낮은 입력레벨에서도 Doherty 증폭기의 효율을 개선 할 수 있었다. 제안된 구조를 이용한 Doherty 증폭기는 기존의 전력증폭기에 비해 PAE는 8 %, IMD3는 -5 dBc 개선하고, 모든 입력전력레벨에서 30 % 이상의 고효율을 가질 수 있었다.

• Journal of electromagnetic engineering and science
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• 제9권3호
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• pp.152-158
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• 2009

We have developed a novel digital feedback predistortion(DFBPD) linearization based on RF feedback PD for the wide bandwidth modulated signals. The wideband PD operation is carried out by combining the DFBPD and memory lookup table(LUT). To experimentally demonstrate the linearization performance of the proposed PD technique for wideband signal, a class-AB amplifier using an LDMOSFET MRF6S23140 with 140-W peak envelope power is employed at 2.345 GHz. For a forward-link 2FA wideband code-division multiple-access signal with 10 MHz carrier spacing, the proposed DFBPD with memory LUT delivers the adjacent channel leakage ratio at an 10 MHz offset of -56.8 dBc, while those of the amplifier with and without DFBPD are -43.2 dBc and -41.9 dBc, respectively, at an average output power of 40 dBm. The experimental result shows that the new DFBPD with memory LUT provides a good linearization performance for the signal with wide bandwidth.

• Journal of electromagnetic engineering and science
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• 제9권2호
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• pp.78-84
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• 2009

This paper represents the effects of drain bias on the linearity and efficiency of an analog pre-distortion power amplifier(PA) for wideband code division multiple access(WCDMA) repeater applications. For verification, an analog predistorter(APD) with three-branch nonlinear paths for memory-effect compensation is implemented and a class-AB PA is fabricated using a 30-W Si LOMaS. From the measured results, at an average output power of 33 dBm(lO-dB back-off power), the PA with APD shows the adjacent channel leakage ratio(ACLR, ${\pm}$5 MHz offset) of below -45.1 dBc, with a drain efficiency of 24 % at the drain bias voltage($V_{DD}$) of 18 V. This compared an ACLR of -36.7 dEc and drain efficiency of 14.1 % at the $V_{DD}$ of 28 V for a PA without APD.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1706-1710
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• 2006

Leptin receptor (OBR) is a member of the class I cytokine receptor family. It signals mainly via the JAK/STAT pathway and plays an important role in regulating body energy storage and metabolism. This study was designed to investigate the effects of the OBR gene on chicken growth and body composition. Broiler lines selected divergently for or against abdominal fat were used. Primers for the exon9-region in the OBR gene were designed using chicken genomic sequences from the public genome domain. A C/A single nucleotide polymorphism (SNP) was found and its three genotypes (AA, AB and BB) were identified in this population. The results showed that the OBR polymorphism was associated with fatness traits, such as abdominal fat weight and abdominal fat percentage. This research suggests that OBR or a linked gene has effect on fat deposition in the chicken.

• 대한치과교정학회지
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• 제22권1호
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• pp.17-30
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• 1992

Since 1984, many patients have been treated with Multiloop Edgewise Archwire (MEAW) Technique and diagnosed with ODI (Overbite Depth Indicator) and APDI (Anteroposterior Dysplasia Indicator) by the authors. 234 samples of them were selected randomly for the statistical analysis (age, sex, Angle's classification, treatment period, extraction, ODI etc.). Especially, ODI was analysed statistically and its application methods were reviewed. The results and conclusions were as follows: 1. On the 150 patients with normal overbite, the mean values of Class I, II, III malocclusion were $67.5^{\circ}$, $72.2^{\circ}$ and $59.0^{\circ}$. They were significantly different on the level of p < 0.01. 2. In normal overbite samples, ODI decreased with the increase of APDI and the correlation coefficient was -0.54. It seems that this result reflects the characteristics of AB to mandibular plane angle. 3. The regression equation was Y = - 0.57X + 114.64, where X is APDI and Y is ODI. In cases of small or large APDI, it seems to be absurd that the patient's ODI is compared with the mean ODI to differentiate diagnostically the open bite or deep bite tendency from the normal.

• 한국정보통신학회논문지
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• 제16권5호
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• pp.1009-1014
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• 2012

본 논문은 LTE-Advanced 시스템에 적용할 수 있는 2,500 MHz~2,570 MHz 대역 0.13-${\mu}m$ CMOS RF front-end 송신기를 제안하며 I/Q 상향주파수변환기와 구동증폭기로 구성되어있다. 상향주파수변환기는 우수한 선형특성을 얻기 위해 공진회로를 부하로 사용하였으며 국부발진신호의 누설을 줄이기 위해 전류 보상회로를 사용하였다. 또한, 제안하는 구동증폭기는 높은 전류 효율과 우수한 선형특성을 확보하기 위해 Class AB 바이어스 상태로 설계되었다. 측정 결과 제안하는 RF front-end 송신기는 최대 +6 dBm의 출력 파워를 제공하며, +0 dBm 출력 시 이미지 신호 및 국부 발진 누설 신호와 40 dBc의 차이를 보인다. 제작된 칩은 1.2 V의 공급 전압으로부터 36 mA 전류를 소모한다.

• Bulletin of the Korean Chemical Society
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• 제14권4호
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• pp.491-496
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• 1993

A class A ${\beta}$-lactamase from Staphylococcus aureus PC1 complexed with 3R,5R-clavulanate is studied. The starting geometry for the computation is the crystal structure of the ${\beta}$-lactamase. Docking of the clavulanate to the enzyme is done exploiting the requirements of electrostatic and shape complementarity between the enzyme and clavulanate. This structure is then hydrated by water molecules and refined by energy minimization and short molecular dynamics simulation. In the energy refined structure of this complex, the carboxyl group of the clavulanate is hydrogen bonded to Lys-234, and the the carbonyl carbon atom of the clavulanate is adjacent to the $O_{\gamma}$ of Ser-70. It is found that a crystallographic water molecule initially located at the oxyanion hole, which is formed by the two -NH group of Ser-70 and Gln-237, is replaced by the carbonyl oxygen atom of the 3R,5R-clavulanate after docking and energy reginement. The crystallographic water molecules are proved to be important in ligand binding. Glu-166 residue is found to be repulsive to the binding of clavulanate, which is in agreement with experimental observation. Arg-244 residue is found to be important to the binding of clavulanate as well as to interaction with C2 side chain of the clavulanate. The electron density redistribution of the clavulanate on binding to the ${\beta}$-lactamase in studied by an ab initio quantum-mechanical calculation. A significant redistribution of electron density of the clavulanate is induced by the enzyme, toward the enzyme, toward the transition state of the enzymatic reaction.