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A Study on Mobile Antenna System Design with Tri-band Operation for Broadband Satellite Communications and DBS Reception (광대역 위성 통신/방송용 삼중 대역 이동형 안테나 시스템 설계에 관한 연구)

  • Eom Soon-Young;Jung Young-Bae;Son Seong-Ho;Yun Jae-Seung;Jeon Soon-Ick
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.5 s.108
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    • pp.461-475
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    • 2006
  • In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

Evaluation of apical canal shapes produced sequentially during instrumentation with stainless steel hand and Ni-Ti rotary instruments using Micro-computed tomography (Stainless steel hand file과 Ni-Ti rotary file을 이용한 근관 형성시 근단부 근관 형태의 순차적 변화에 대한 평가)

  • Lee, Woo-Jin;Lee, Jeong-Ho;Chun, Kyung-A;Seo, Min-Seock;Yoo, Yeon-Jee;Baek, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.36 no.3
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    • pp.231-237
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    • 2011
  • Objectives: The purpose of this study was to determine the optimal master apical file size with minimal transportation and optimal efficiency in removing infected dentin. We evaluated the transportation of the canal center and the change in untouched areas after sequential preparation with a #25 to #40 file using 3 different instruments: stainless steel K-type (SS K-file) hand file, ProFile and LightSpeed using microcomputed tomography (MCT). Materials and Methods: Thirty extracted human mandibular molars with separated orifices and apical foramens on mesial canals were used. Teeth were randomly divided into three groups: SS K-file, Profile, LightSpeed and the root canals were instrumented using corresponding instruments from #20 to #40. All teeth were scanned with MCT before and after instrumentation. Cross section images were used to evaluate canal transportation and untouched area at 1-, 2-, 3-, and 5- mm level from the apex. Data were statistically analyzed according to 'repeated nested design' and Mann-Whitney test (p = 0.05). Results: In SS K-file group, canal transportation was significantly increased over #30 instrument. In the ProFile group, canal transportation was significantly increased after preparation with the #40 instrument at the 1- and 2- mm levels. LightSpeed group showed better centering ability than ProFile group after preparation with the #40 instrument at the 1 and 2 mm levels. Conclusions: SS K-file, Profile, and LightSpeed showed differences in the degree of apical transportation depending on the size of the master apical file.

Future Development of Genetics and the Broiler (BROILER 육종기술의 전망)

  • 오봉국
    • Korean Journal of Poultry Science
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    • v.8 no.1
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    • pp.1-5
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    • 1981
  • In trying to predict the effect of genetics on the broiler in the year 2000, this is a relatively short period of time as far as broiler genetics in concerned. Modern broiler genetics started around 1945 and tremendous gains when made in past 35 years. Futher improvements on broiler will depend on the evolution and revolution: 1. Evolution: (1) Growth rate has been made 4-5% per year. (2) Feed conversion has improved approximately 1% per year. (3) Abdominal fat is becoming a major complaint in broiler. (4) Because of the changing life-style, broiler meat sales in the future will be more and more in cut-up form. (5) Breeding for stress resistance and selection for docile temperament can be important in order to funker improve fled efficiency. (6) In female parent stock, reproduction characteristics are in many can negatively correlated with the desired broiler traits. (7) Egg production and hatchability in moot commercial parent nod m at a fairly high level. (8) In male parent stock, the heavier and mon super-meat-type male lines are desired to Product better broilers. 2. Revolution: Trying to forecast revolutionary change in broiler genetics is highly speculative, as sudden change are aften unpredictable. (1) Species hybridization, such as a turkey-chicken cross (2) Biochemical tools, such as blood typing. (3) Mutation breeding by radiation or chemical mutagentia. (4) Broiler breeding would be to change the phenotypic appearance by single gene, such as naked, wingless. (5) Changes in production techniques. such as growing in cage or growing in filtered air positive pressure houses.

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Determination of shear wave velocity profiles in soil deposit from seismic piezo-cone penetration test (탄성파 피에조콘 관입 시험을 통한 국내 퇴적 지반의 전단파 속도 결정)

  • Sun Chung Guk;Jung Gyungja;Jung Jong Hong;Kim Hong-Jong;Cho Sung-Min
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.09a
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    • pp.125-153
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    • 2005
  • It has been widely known that the seismic piezo-cone penetration test (SCPTU) is one of the most useful techniques for investigating the geotechnical characteristics including dynamic soil properties. As the practical applications in Korea, SCPTU was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTU waveform data obtained from the testing sites, the first arrival times of shear waves were and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity profiles (VS) were derived based on the refracted ray path method based on Snell's law and similar to the trend of cone tip resistance (qt) profiles. In Incheon area, the testing depths of SCPTU were deeper than those of conventional down-hole seismic tests. Moreover, for the application of the conventional CPTU to earthquake engineering practices, the correlations between VS and CPTU data were deduced based on the SCPTU results. For the empirical evaluation of VS for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification Index (IC), the authors suggested the VS-CPTU data correlations expressed as a function of four parameters, qt, fs, $\sigma$, v0 and Bq, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the down-hole seismic test during SCPTU and the conventional CPTU, it is shown that the VS-CPTU data correlations for all soils clays and sands suggested in this study is applicable to the preliminary estimation of VS for the Korean deposits and is more reliable than the previous correlations proposed by other researchers.

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The Empirical Study on the Effects of the Team Empowerment caused by the Team-Based Organizational Structure in KBS (팀제가 팀 임파워먼트에 미치는 영향에 관한 연구;KBS 팀제를 중심으로)

  • Ahn, Dong-Su;Kim, Hong
    • 한국벤처창업학회:학술대회논문집
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    • 2006.04a
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    • pp.167-201
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    • 2006
  • Korean corporations are transforming their vertical operational structure to a team-based structure to compete in the rapidly changing environment and for improved performance. However, a high percentage of the respondents in KBS said that despite the appearance of the present team structure, the organization operates much like a vertically-structured organization. This result can be attributed to the lack of study and implementation toward the goal of empowerment, the key variable for the success of the team-based structure. This study aims to provide policy suggestions on how to implement the process of empowerment, by investigating the conditions that hinder the process and the attitude of the KBS employees. For the cross-sectional study, this thesis examined the domestic and international references, conducted a survey of KBS employees, personal interviews and made direct observations. Approximately 1,200 copies of the Questionnaire were distributed and 474 were completed and returned. The analysis used SPSS 12.0 software to process the data collected from 460 respondents. For the longitudinal-study, six categories that were common to this study and "The Report of the Findings of KBS Employees' View of the Team Structure" were selected. The comparative study analyzed the changes in a ten-month period. The survey findings showed a decrease of 24.2%p in the number of responses expressing negative views of the team structure and a decrease of 1.29%p in the number of positive responses. The findings indicated a positive transformation illustrating employees' improved understanding and approval of the team structure. However, KBS must address the issue on an ongoing basis. It has been proven that the employee empowerment increases the productivity of the individual and the group. In order to boost the level of empowerment, the management must exercise new, innovative leadership and build trust between the managers and the employees first. Additional workload as a result of shirking at work places was prevalent throughout all divisions and ranks, according to the survey data. This outcome leads to the conclusion that the workload is not evenly distributed or shared. And the data also showed the employees do not trust the assessment and rewards system. More attention and consideration must be paid to the team size and job allocation in order to address this matter; the present assessment and rewards system need to be complemented. The type of leadership varies depending on the characteristics of the organization's structure and employees' disposition. KBS must develop and reform its own management, leadership style to suit the characteristics of individual teams. Finally, for a soft-landing of KBS team structure, in-house training and education are necessary.

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Current Status of Children on Peritoneal Dialysis in Korea : A Cross-Sectional Multicenter Study (소아복막투석의 현황: 다기관 공동연구 결과보고)

  • Youn, Ji-Seok;Lee, Joo-Hoon;Park, Young-Seo;Yim, Hyung-Eun;Paik, Kyung-Hoon;Yoo, Kee-Hwan;Ha, Il-Soo;Cheong, Hae-Il;Choi, Yong
    • Childhood Kidney Diseases
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    • v.13 no.2
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    • pp.176-188
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    • 2009
  • Purpose : Peritoneal dialysis (PD) is the major form of dialysis in use for infants and children with end-stage renal disease (ESRD). The aim of this study was to gain insight into the current status of children on PD in Korea. Methods : In May 2008, questionnaires were sent to the pediatric nephrologists via e-mail. Four centers replied and those data were reviewed. Results : A total of 103 patients were included in this study. Male to female ratio was 1.6:1. Mean age was $11.5{\pm}4.9$ years (0-19 years). Primary renal diseases diagnosed were as follows: primary glomerular disease (34%), chronic pyelonephritis-reflux nephropathy (14.6%), systemic disease (9.7%), renal hypoplasia/dysplasia (8.7%), heredofamilial disease (6.8%), vascular disease (3.9%), drug-induced nephropathy (1.0%), and unknown (12.6%). PD modalities were as follows: CAPD (42.7%), CCPD (27.2%), NIPD (11.7%), and Hybrid (18.4%). Weekly total Kt/V was $2.1{\pm}0.7$ (0.3-4.1). Results of peritoneal equilibrium test were as follows: low 36.8%, low average 31.6%, high average 19.7%, and high 11.8%. Z-score for weight was $-1.00{\pm}1.20$ (-4.54~+2.50). Z-score for height was $-1.55{\pm}1.65$ (-9.42~+1.87). Growth hormone was administered in 24.3% of patients. Anti-hypertensive drugs were administered in 64.0% of patients. Laboratory findings were as follows: hemoglobin $10.5{\pm}1.4$ g/dL, calcium $9.7{\pm}0.7$ mg/dL, phosphorus $5.4{\pm}1.4$ mg/dL, and parathyroid hormone $324.2{\pm}342.8$ pg/mL. Conclusion : Primary glomerular disease was the most common cause of ESRD. CAPD was the most prevalent PD modality. Low and low average peritoneal transport type were common. Growth disturbance were noted in many patients. Some patients had hypertension even with anti- hypertensive drugs. Calcium-phosphorus levels were maintained adequately, but many patients had secondary hyperparathyroidism.

Breeding of Strawberry 'Okmae' for Forcing Culture with Less Labor Requirement for Fruit Thinning (적과 노력 절감용 촉성 딸기 '옥매' 품종 육성)

  • An, Jae Uk;Shim, Jae Suk;Yoon, Hae Suk;An, Chul Geon;Hwang, Yeon Hyeon;Chang, Young Ho;Shon, Gil Man;Rho, Chi Woong;Jeong, Byoung Ryong
    • Horticultural Science & Technology
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    • v.30 no.6
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    • pp.780-783
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    • 2012
  • A new strawberry cultivar (Fragaria ${\times}$ ananassa Duch.) 'Okmae' was developed from a cross between 'Toyonoka' and 'Maehyang'. This cultivar has a good fruit quality and suitable number of flowers per cluster for labor saving in fruit thinning. 'Gyoengnam No. 1' was selected as an elite line with vigorous plant growth, higher soluble solids content and fruit firmness after examining its characteristics and productivity in forcing cultures from 2007 to 2009. Farmer's field trial of 'Gyoengnam No. 1' was conducted in 2010 and it was registered as 'Okmae' thereafter. The general characteristics of 'Okmae' are vigorous growth habit, erect plant type, less number of leaf and elliptic leaf shape. 'Okmae' has long peduncle and 9-10 flowers per flower cluster which need less labor for fruit thinning. Fruits of 'Okmae' are conical having a bright red and glossy skin color. Although 'Okmae' has a smaller average fruit number per plant of 21.9 than that of the control cultivars, it's possible to produce high yield because of greater fruit weight of 26.0 g. 'Okmae' showed a high soluble solids content of $11.6^{\circ}Brix$, low acidity of 0.37%, and high firmness of $14.5g{\cdot}mm^{-2}$. It is sensitive to anthracnose and powery mildews, but high-quality strawberry can be harvested by using effective control measure.

The Surgical Treatment of Atrial Fibrillation in Patients Undergoing Simultaneous Open Heart Surgery (심장세동의 수술요법)

  • Kim, Gi-Bong;Lee, Chang-Ha;Son, Dae-Won
    • Journal of Chest Surgery
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    • v.30 no.3
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    • pp.287-292
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    • 1997
  • .Itrial fibrillation is one of the most common cardiac arrhythmias requiring treatment. About 60% of patients with mitral valvular disease have atrial fibrillation and one third of patients with atrial fibrillation may have the past history of thromboembolic events. Between April 1994 and June 1995, 20 patients with organic heart diseases combined with atrial fibrillation underwent open heart surgery including Cox-maze 111 procedure. There were 6 men and 14 women with an average age of 48 years (range, 31 to 66 years). Nineteen patients had valvular heart diseases and 1 ventricular septal defEct (VSD). Mean duration of atrial fibrillation was 36 months (:42 months) (range, 1 to 132 months). T e past medical history of thromboembolic events was positive in 7 patients (35%) and left atrial thrombus was detected in 9 patients (45%). The concomitant procedures were mitral valve replacement (MVR) and aortic valve replacement (AVR) in 5 patients, MVR in 4, MVd and tricuspid annuloplasty(TAP) in 4, mitral valvuloplasty(Mln) in 3, Mln and Tln in 1, MIW and coronary artery bypass surgery in 1, AVR in 1, and patch closure of VSD in 1. Mean aortic cross-clamping time was 175 minutes (range, 116 to 270 minutes). Atrial fibrillation recurred in 16 patients (80%) during the early postoperative period, but, recurrent atrial fibrillation was converted to regular rhythm at postoperative forty-first day in average. There was no early or late death in this series of 20 patients and postoperative complications were inappropriate tachycardia in 5 patients (25%), low cardiac output syndrome in 3 (15%), aggravated hemiplegic in 1, and acute renal failure in 1. Mean follow-up interval of patient was 16.5 months (range, 10.5 to 24 months) and all patients are currently in regular rhythm. Seventeen patients (85%) are in sinus rhythm and 3 (15%) in junctional rhythm. Right atrial contraction was detected in 95% of patients and left atrial contraction in 63% on postoperative transthoracic echocardiogram. The surgical treatment of atrial fibrillation concomitant with open heart surgery is warranted in the recent clinical setting of improved myocardial protection technique, considering the untoward side-effects of atrial fibrillation.

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An Analysis of Body Shapes in Aged Abdominal Obese Women for Apparel Pattern Design (복부비만 노년 여성의 의복패턴설계를 위한 체형연구)

  • Kim, Soo-A;Choi, Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.12 s.159
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    • pp.1690-1696
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    • 2006
  • The purpose of this study is to provide the basic data useful in designing apparel patterns for aged abdominal obese women. The body measurements of 318 women were taken at random, whose ages were over 60 and fields of action were colleges, sports centers, or business sites in Seoul and the neighboring districts. A total of 33 features in the upper body and lower body were used fer the anthropometric measurement and analysis using anthropometry. The collected measurement data were processed statistically using the SPSS 12.0 program for technical statistical analysis, t-test, frequency analysis, correlation analysis. The results of the study are as follows. 1. Subjects were classified into two groups as a result of analysis for measurement data. It was revealed that 251(about 79 percent) women of total subjects(n=318) have a characteristic of abdominal obese body type and elderly women of these group usually had big abdomen rather than hip. The criteria of abdominal obesity based on waist-hip ratio, WHR(=0.85). 2. Aged abdominal obese women have shown much larger size in most body measurements except items of some vertical length, such as bust ponit-bust point, font interscye, back interscye with circumference and depth of armscye, bust, waist, abdomen and hip while showing no difference in height, biacrominal breadth, hip width, neck shoulder point to breast point, crotch length. 3. Vervaeck index(=100.1) and Rohrer index(=1.7) indicated that the abdominal obese women were fat in overall body. And aspect ratio of waist(=0.86), abdomen(=0.92) and hip(=0.75) also appeared high that the shape of cross sections in those regions was similar to a figure of circle 4. In view of the correlation coefficient between hip circumference and the rest measurement items, and between hip circumference inclusively of the abdomen protrusion and the rest measurement items, there were found some differences for each group. In case of Group (abdominal obese group), the former is smaller than the other. 5. In case of Abdominal obese women, hip circumference inclusively of the abdomen protrusion is more mutually related to the rest items related to make apparel pattern as waist circumference, depth of armscye and so on than what hip circumference is. This result indicated which must be considered hip circumference inclusively of the abdomen protrusion to make apparel patterns for abdominal obese women unlike women of common body types.

Analysis of phenotypic characterization of segregation population developed by crossing in Flammulina velutipes (팽이버섯(Flammulina velutipes) 교잡분리집단의 형태학적 특성 분석)

  • Woo, Sung-I;Kong, Won-Sik;Kim, Eun-Seou;Jang, Kab yeul;Shin, Pyung-Gyun;Oh, Youn-Lee;Oh, Min ji;Nam, Youn-keol;Kim, Kyung-Soo
    • Journal of Mushroom
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    • v.13 no.3
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    • pp.217-222
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    • 2015
  • This study was conducted to obtain a growth correlation of basal information from the development of disease resistant Flammulina velutipes cultivars through back-crossing between the strains of wild-type brown monokaryon 4019-20 and the derivative of commercial quality white monokaryons 3. The two strains were selected to back-cross for further enhancing their latent attributes and growth characteristics. The parents of 4019-$20{\times}M3$ back-crossed to reproduce $F_1$, M3-Sn. Using $F_1$, M3-Sn procured and isolated into 94 monokaryon strains. Further examination of growth characteristics carried out by back-crossing between M3 and $BC_1F_1$ from M3-n dikaryon. Monokaryon exhibited an irregular growth pattern and demonstrated to be sluggish development in the sawdust medium. However $BC_1F_1$(M3-n) dikaryon strains confirmed mostly regular growth pattern and demonstrated ordinary growth in the sawdust medium. The fruitbody of $BC_1F_1$ confirmed as light-brown colour to be the dominant gene. The colour distributions of fruitbody, $BC_1F_1$, resulted as follows; 7% of dark brown, 25% of brown, 27% of light brown, 16% of ivory and 25% of white. The ratio of the other color to white showed 3 to 1 which suggested two major genes were related to fruitbody color.