• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.657-666
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• 2002

In this paper, a new broadband phase shifter to adjust the slope of dispersive phase characteristic for frequency of transmission network was proposed. The new fundamental network consists of a fixed main line with a length of λ/2 at the center frequency and two double stubs, each with a length of λ/8 at the center frequency, which are open and shorted, respectively, and which are shunted at the edge points of the main line. Characteristic impedances of the main line and two parallel double stubs are adjusted to produce a minimum phase error and to obtain an input and output match at the desired phase shift. Especially, the proposed structure is especially suitable for a broadband phase shifter with large phase shifts more than 90$^{\circ}$, and it is operated in the octave bandwidth. To verify the usefulness of a new broadband phase shifter, each 45$^{\circ}$-, 90$^{\circ}$-, 180$^{\circ}$-bit phase shifter and 3-bit phase shifter(45$^{\circ}$-phase step), which is cascaded in series, operated at the center frequency 3 GHz were designed, fabricated and experimented. The measured results were in very close agreement with the corresponding simulation results over the bandwidth of I/O impedance match and phase error for each phase shift.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.25-32
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• 2024

Frankliniella occidentalis and Thrips palmi are economically important pests of cucumber. The chemicals used to control them can be effective; however, they should not be used frequently on cucumbers that are consumed raw. Banker plants were selected to increase the control efficiency of Orius laevigatus, a natural enemy that can replace the chemicals. The hatching rate, emergence rate, nymph developmental period, survival rate, and reproductive capacity (fecundity and oviposition period) of O. laevigatus for four plants (moss rose, basil, broad bean, and cucumber) were investigated. The density of O. laevigatus on two selected banker plants was investigated in a cucumber greenhouse. The hatching rate of O. laevigatus eggs was highest at 92% in moss rose; however, there was no significant difference in survival rates between moss rose and basil. The fecundity and oviposition period of O. laevigatus were better in moss rose than in basil, with no significant difference between them. The flowering period of basil was longer than that of moss rose, from April to September. Therefore, basil has potential value as a banker plant for O. laevigatus and is expected to increase the biological control effect of O. laevigatus.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.524-530
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• 2008

In this study, the effects of feed containing citrus byproducts on the physicochemical characteristics and palatability of Korean native chickens were investigated. The Korean native chickens used in this study were divided into two groups: T0 (chickens that were not fed citrus byproducts until they were 39 weeks old) and T1 (chickens that were fed citrus byproducts). The feed given to the T1 chickens was the same as that given to the T0 chickens for the first 16 weeks. Between weeks $17{\sim}39$, the feed given to the T1 chickens was prepared by adding 4% of the citrus byproducts to the feed given to the T0 chickens. The chickens used in the experiment were chilled for 2 days after being sacrificed. The feed containing citrus byproducts did not cause any statistically significant differences in the breast and thigh characteristics of lightness ($L^*$ value), redness ($a^*$ value), yellowness ($b^*$ value), water-holding capacity, frozen loss, thawing loss and boiling loss. As for the rheological properties, there was no statistically meaningful difference in the breast/thigh characteristics of springiness, cohesiveness, gumminess, and chewiness between the T0 and T1 chickens. However, hardness and shear force were significantly lower in the T1 chickens than in the T0 chickens (p<0.05). The acid and peroxide values were also lower in the T1 chickens than in the T0 chickens, but the difference was not statistically significant. Antioxidant activity was better in the T1 chickens than in the T0 chickens. Thus, the results of the present study show that consumption of citrus byproducts did not affect the color and smell of raw meat. The palatability of boiled meat was significantly better in the T1 chickens than in the T0 chickens.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.469-485
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• 1996

Orthodontic patients are individuals that grow and develop ; therefore selection of the proper time for orthodontic treatment is considered to be one of most difficult and yet difficult factor. Since the development of cephalometric X-ray, amount and Pattern of craniofacial growth change with aging could be predicted and be came useful in the process of orthodontic treatment. The relationship between the mean values of cephalometric measurements and body height and weight was studied among the groups(boys and girls) of Korean children from the ages 6-years to 17-years. 409 boys and 437 girls with no abnormality in growth and development and no history of orthodontic treatment from the ages of 6 years to 17 years were chosen as subjects Cephaloment X-ray were taken for 3 years and hard tissue analysis based on Burstone's COGS, which was devided into measurements of 6 parts(Cranial base, Maxillar and Mandible, Dental measurements). The relationship between craniofacial growth and height & weight was studied. The following conclusions were obtained : 1. The maximum growth in the measurements of cranial base, N-Ar(FH), N-Ba(FH) corresponded with the age with the maximum increase in body height & weight in both boys and girls. 2. Genial angle gradually decreased with aging in both boys and girls. 3. N-ANS(L) showed greater amount of growth than ANS-Ne(L), and this had greater influence on facial profile. 4. N-A-$Pog^{\circ}$ decreased with aging, and mandibular growth exceeded maxillary growth in amount and rate. 5. Length of Y-axis Increased, but Y-axis to FH plane remained constant. This show that mandible grows at a constant angulation to cranial base. 6. As permanent teeth erupt, interincisal angle deceased.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.385-394
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• 2008

Larvae of Monochamus saltuarius showed normal growth and development on conifers of Pinus koraiensis, P. densiflora, Abies holophylla, Larix leptolepsis, P. bungeana, and P. rigida, respectively, but the conifers influenced significantly the body weight and the survival rate of larvae. Though the larval body weights were in a wide spectrum among treatments, growth curves of them were very similar from each other, showing continuous increase from the early larval stage to about 3 months old. The body weight was decreased slightly after the feeding period of the early 3 months. The size of larvae and adults became the largest from P. bungeana fed larvae. The mid-sized ones were from P. koraiensis, P. densiflora and A. holophylla. Small ones came from L. leptolepsis and P. rigida. The larval growth was retarded without water supply. Overall survival rates from the early stage of a larva to a fertile adult were 53.6% from P. koraiensis; 51.8%, P. densiflora; 34.7%, A. holophylla; 17.8%, P. bungeana; 16.7%, L. leptolepsis; and 12.3%, P. rigida. Adults from larvae fed the 6 species of conifers, respectively, were grown into the reproductively potent adults, which laid viable eggs. A few of overwintered larvae did not pupate and remained still as a larva until the late October of the year. Data from the field survey, the head width emerged from P. koraiensis was larger than that of L. leptolepsis. The adult emergence hole in P. koraiensis was larger also. While, the size of the emergence hole was larger in the artificially innoculated log of P. koraiensis, which was kept for a larva to be with a minimized food competition and sufficient water supply, than that of the field.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.54-55
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• 2003

해수관상용으로 그 인기도가 높은 상어류는 모두가 자연에서 채집된 후 관람용 대형수조 또는 개인용 소형수조 내에서 순치 후 관상용으로 사육되고 있다. 그러나, 자연에서 채집된 대부분의 개체는 인위적인 수조 시설 내에서의 생활에 적응하는데 실패하여 결국 거의 대부분의 개체가 짧은 기간 내에 사망하게 된다. 따라서 이 연구는 인공 종묘 생산 시설에서 해수 관상용 상어류의 종묘 확보를 목적으로 실시하였다. 우리나라 제주 연안에서 채집이 비교적 용이한 까치상어 Triakis scyllium와 별상어 Cynias manazo 2종의 상어 친어를 확보하여 인공 사육 시설에서 사육하면서 수조 내에서의 자연 교미와 자연 산란에 성공하였다. 친어와 치상어의 사육관리는 자연해수를 사용하여 15~40ton 크기의 콘크리트 수조에서 사육하면서 전갱이와 같은 생사료 또는 전갱이와 어분을 주성분으로 하는 습사료를 만들어 1일 1회 급이하였다. 까치상어의 인공 종묘는 수 차례의 사산을 거듭한 끝에 2003년 5월 18일과 6월 8일 두 차례에 걸쳐서 매우 활력이 좋은 상태의 치어가 출산하였다. 별상어도 수 차례의 사산을 거듭한 끝에 2003년 5월 25일 건강한 상태의 치어를 출산시키는데 성공하였다. 지금까지 산출된 까치상어의 출산시 평균 전장은 25.70$\pm$0.88cm 평균 체중은 58.32$\pm$4.86g이었으며, 별상어의 출산시 치어의 평균 전장은 27.26$\pm$0.57cm였고 평균 체중은 55.32$\pm$1.69g로 두 종 상어의 평균 전장과 평균 체중은 유사한 경향을 보였다. 그러나, 산출 후 사육 관리 과정에서 관찰된 까치상어와 별상어의 월간 성장 중 전장을 비교한 결과, 까치상어는 1개월 전 대비 15.06%의 성장을 보였으나, 별상어는 3.15%의 성장을 보여 까치상어 보다는 별상어의 길이 성장이 느린 것을 알 수 있었다. 까치상어와 별상어의 월간 성장 중 체중을 비교한 결과에서도 까치상어는 1개월 전 대비 34.11%의 성장을 보였으나, 별상어는 2.25%의 성장을 보여 까치상어 보다는 별상어의 체중 성장이 매우 느린 것을 알 수 있었다. 출산 관리중인 까치상어와 별상어 치어의 성비를 조사한 결과, 까치상어는 ♀:♂=1:1.28, 별상어는 ♀:♂=1:2.50으로 별상어의 암 수 성비가 매우 불균형한 것을 알 수 있었다. 그리고 까치상어와 별상어의 암ㆍ수간 성장 차이를 조사한 결과, 까치상어와 별상어의 암ㆍ수간 성장 (전장, 체장 및 체중)에는 큰 차이가 없었다. 현재, 인공 사육 시설에서 관리중인 까치상어는 64마리이며 별상어는 7마리이다. 결국 소형의 수족관내에서 해수 관상어로서 사육하기 위한 조건으로서 너무 급격한 성장을 하는 어종인 경우에는 관상 기간이 짧아져 조기 폐기하여야 하는 단점을 감안하면 까치상어 보다는 별상어의 관상가치가 높을 것으로 판단되며, 반대로 대형 관람용 수족관의 경우에서는 별상어 보다 성장이 빠르고 운동력이 활발한 까치상어를 전시관람용으로 이용할 경우 전시효과가 높을 것으로 판단된다.

• Journal of the Korean Magnetics Society
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• v.11 no.6
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• pp.272-277
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• 2001

A spin valve structure of Ta/NiFe/CoFe/Cu/CoFe/Ru/CoFe/FeMn/Ta which has a synthetic antiferromagnet (CoFe/Ru/CoFe), was fabricated by using a magnetron sputtering system. The thickness and composition of magnetic free and pinned layers affect the magnetic properties such as exchange interaction strength of each layer and so on. Even though Rutherford Backscattering Spectrometry (RBS) has advantages of quantitative and non-destructive analysis, it is almost impossible to determine the thickness and composition of magnetic thin films using lBS because of its poor mass resolution for a higher atom number (Z>20). In this study, quantitative analysis of the element composition and thickness for the spin valve sample was performed by combining both Proton Induced X-ray Emission Spectrometry (PIXE), which is one of element specific analysis techniques, and grazing-exit RBS with a highly improved depth resolution and absolute quantitative analysis. For the quantitative analysis, standardization of PIXE was carried out with NiFe, CoFe, and FeMn layers, which are one of constituent layers of spin valve films. Through PIXE standardization and the aid of PHE experimental results of the spin valve sample, ire overlapped signal in a grazing-exit RBS spectrum were successfully resolved and the thickness of the Ru layer was determined with a resolution of ∼1 .

• Korean journal of applied entomology
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• v.36 no.1
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• pp.88-95
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• 1997

Olfactometer was used to find the attractiveness of kairomone extracted from gypsy moth (Lymantria dispar) to the egg parasitoid (Ooencyrtus kuvanae). The attractiveness of kairomone extracted from scales and hairs which were attached to the surface of the eggs were higher than that of whole eggs with 79.9% and 67.6% respectively. The probing lantency of the egg parasitoid on the extract of scales and hairs were 115.5 sec. and that of whole eggs were 113.2 sec. Eggs taken from egg mass were shown 91.0% of attractiveness to the egg parasitoid, however only 15% of egg parasitoid were attracted by follicles dissected from the host ovary. The probing latency of egg mass was faster than that of follicles dissected from the host with 84.2 sec. and 114.0 sec. respectively. Egg parasitoid showed the most active attractiveness (88.0%), relatively longer examing period (89.2 sec.) and shorter probing latency (26.8 sec.) to the adhesive materials secreted from reproductive accessory glands of the host. Out of six organic solvents used for the extraction of kairomone from the host egg mass, n-hexane fraction received the most active response from xthe egg parasitoid and the parasitoid reared in vivo showed 3 times higher attractiveness to the n-hexane fraction than that of in vitro.

• Korean Journal of Poultry Science
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• v.16 no.1
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• pp.9-15
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• 1989

This study was conducted to estimate genetic parameters for egg yolk cholesterol. Content of egg yok cholesterol was measured for a total of 473 hens of White Leghorn line. Cholesterol values were obtained from tee consecutively laid eggs when hens were 53 weeks of age. The yolk of each egg was weighted and freeze dried. Dried egg yolks were stored at -2$0^{\circ}C$ until analyzed. The results obtained from this study were as follows; 1. Yolk cholesterol content was measured in average $56.00\pm$0.194 mg/g dry yolk. 2. Heritability from the sire component of variance was $0.522\pm$0.215 and from the sire＋dam component of variance $0.33\pm$0.209. 3. Estimates of phenotypic correlation between your cholesterol and other factors such as body weight at 20 weeks of age, age at first egg, 40-week total egg number, egg Production rate: 53-week egg weight and 53-week yolk weight were -0.0208, -0.0321, -0.0378, -0.0834, 0.0790 and 0.1624, respectively. And genetic correlation coefficients for each item in the order were -0.5293, 0.7105, -0.4062, -0.0254, 0.2164 and 0.5027, respectively. 4. These results suggest the possibility that egg Yolk cholesterol should be reduced through selecting of sire families. To breed for low egg yolk cholesterol, it makes age at first egg earlier and enhances total egg number so that we can obtain the high rate of egg Production.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.742-750
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• 2020

The flow noise generated by hull appendages is directly related to the performance of the sonar in terms of self-noise and induces a secondary noise source through interaction with the propeller and rudder. Thus, the noise in the near field should be analyzed accurately. However, the acoustic analogy method is an indirect method that is not used to simulate the propagation of an acoustic signal directly; therefore, diffraction, reflection, and scattering characteristics cannot be considered, and near-field analysis is limited. In this study, the propagation process of flow noise in water was directly simulated by using the lattice Boltzmann method. The lattice Boltzmann method could be used to analyze flow noise by simulating the collision and streaming processes of molecules, and it is suitable for noise analysis because of its compressibility, low dissipation rate, and low dispersion rate characteristics. The flow noise source was derived using Reynolds-averaged Navier-Stokes equations for the hull appendages, and the propagation process of the flow noise was directly simulated using the lattice Boltzmann method by applying the developed flow-acoustic boundary conditions. The derived results were compared with Ffowcs Williams-Hawkings results and hydrodynamic pressure results based on the receiver location to verify the usefulness of the lattice Boltzmann method within the near-field range in comparison with other techniques.