• ETRI Journal
• /
• v.24 no.3
• /
• pp.197-204
• /
• 2002

This paper presents the results of the numerical simulation of a multibeam active phased array antenna for a High Altitude Platform Station (HAPS). The simulation takes into account the random errors caused by the non-identity of the array elements and the inaccuracy of the antenna calibration. The results of our statistical simulation show that the strict requirements on the sidelobe envelope for HAPSs can be met when the amplitude and phase distribution errors are minor, a condition which may be achieved by using digital beamforming.

• Journal of Plant Biology
• /
• v.17 no.2
• /
• pp.95-98
• /
• 1974

This experiment was undertaken with the purpose of investigating effect of gibberellin on the growth and electron microscopic ultrastructure of hop(Humulus lupulus var. Hallertau) shoot apex. The results are as follows. 1) The growth of stem in the plots treated with GA(10, 25, and 50ppm) is more predominant than control. The leaves and cones of treated plots turn to pale green. 10ppm plot of GA treatment is the most effective in growth and yield than the others. 2) Under the GA-treated condition, it is believed that the nucleoplasmic index (NP) are higher than the control, and so nucleus, nucleolus, mitochondria, primary cell wall, middle lamella, and etc. tends to be larger than the control. 3) Mitochondria contained in the cell of shoot apex treated with concentration of 10ppm GA was seemed to increases in number and be larger in size than the control.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.59 no.4
• /
• pp.27-42
• /
• 2017

The global rise in atmospheric $CO_2$ concentration and its associated climate change have significant effects on agricultural productivity and hydrological cycle. For food security and agricultural water resources planning, it is critical to investigate the impact of climate change on changes in agricultural productivity and water consumption. APEX-Paddy model, which is the modified version of APEX (Agricultural Policy/Environmental eXtender) model for paddy ecosystem, was used to evaluate rice productivity and evapotranspiration based on climate change scenario. Two study areas (Gimjae, Icheon) were selected and the input dataset was obtained from the literature. RCP (Representitive Concentration Pathways) based climate change scenarios were provided by KMA (Korean Meteorological Administration). Rice yield data from 1997 to 2015 were used to validate APEX-Paddy model. The effects of climate change were evaluated at a 30-year interval, such as the 1990s (historical, 1976~2005), the 2025s (2011~2040), the 2055s (2041~2070), and the 2085s (2071~2100). Climate change scenarios showed that the overall evapotranspiration in the 2085s reduced from 10.5 % to 16.3 %. The evaporations were reduced from 15.6 % to 21.7 % due to shortend growth period, the transpirations were reduced from 0.0% to 24.2 % due to increased $CO_2$ concentration and shortend growth period. In case of rice yield, in the 2085s were reduced from 6.0% to 25.0 % compared with the ones in the 1990s. The findings of this study would play a significant role as the basics for evaluating the vulnerability of paddy rice productivity and water management plan against climate change.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.41 no.2
• /
• pp.66-73
• /
• 2015

Objectives: To assess the validity of the vertical tube-shift method using intraoral periapical radiography (IOPAR) for determining the relationship between the mandibular third molar roots and the inferior alveolar nerve (IAN) canal in comparison with cone-beam computed tomography (CBCT). Materials and Methods: Fifty impacted mandibular third molars were analyzed using the IOPAR vertical tube-shift method and CBCT. The relationship of the IAN canal to the impacted mandibular third molar was recorded as buccal, lingual or in line with the apex and was compared with CBCT findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the vertical tube-shift method in depicting the relationship (buccal/lingual/in line with the apex) of the IAN canal to the third molar root apex was calculated. Results: The sensitivity and specificity PPV and NPV of the IOPAR vertical tube-shift technique was found to be highest for a lingual relationship (100%) followed by buccal (94.4%, 92.3%, 97.1%, and 85.7%) and in line with the apex relationship (88.9%, 95.0%, 80.0%, and 97.4%) of the IAN canal with the third molar root apex, respectively. A statistically significant association was observed between the IOPAR vertical tube-shift method and the CBCT with a P-value <0.01. Conclusion: The vertical tube-shift method can be used as an effective diagnostic tool in assessing the relationship of the IAN canal to the third molar root apex with high sensitivity, specificity, PPV, and NPV.

• Restorative Dentistry and Endodontics
• /
• v.28 no.1
• /
• pp.64-71
• /
• 2003

The purpose of this study was to compare the initial apical file(IAF) first Ole that fits to the apex in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. Eighty anterior teeth with complete apical formation and patent foramens were selected. The samples were randomly divided into 4 groups(GG, OS, GT, PT Group) of 20 teeth each. A file was fit to the apex in each canal and that size recorded. Radicular flaring were completed using different types of instruments. After flaring a file was again fit to the apex in the same manner as before and its size recorded. The results of this study were as follows : 1. The mean diameter of IAF before flaring(file diameters in $mm{\times}10^{-2}$) was $19.81{\pm}8.32$ before and $25.94{\pm}9.21$ after(p<0.05). 2. The increase in diameter of IAF was approximately one file size for all groups. 3. Ranking of increasing diameter of IAF were GG>CT>OS>PT group. There was a statistically significant difference between before and after flaring(p<0.05). 4 Ranking of the time for flaring were GG>GT>OS>PT group. There was a statistically significant difference between GG group and other groups(p<0.05). 5. In the case without change of IAF diameter, they showed decrease in force after flaring when IAF was pulled out from root canal(p<0.05). This study suggested that early radicular flaring increases the file size that is snug at the apex, and awareness of that difference gives the clinician a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.

• Restorative Dentistry and Endodontics
• /
• v.23 no.1
• /
• pp.339-345
• /
• 1998

The purpose of this study was to evaluate the in vitro accuracy of Root ZX(Morita Co., Japan) which is the ratio type electronic apex locator. The 86 extracted human palatal roots of maxillary molar with fully formed apices were used. File lengths with the file tip just visible at the foramen were compared to those measured with Root ZX. For length measuring with Root ZX, saline test model with which the apical 1/3 of each root was submerged into normal saline were designed. The root canal lengths were determined with Root ZX and the radiographs were taken with a file in the canal. The distances from file tips of Root ZX lengths to apecies in radiographs also were measured with Profile projector PJ311(Mitutoyo Co., Japan). The results were as follows : 1. The root canal length determined with electronic apex locator was $0.78{\pm}0.53mm$ shorter than the length with visual measurement. 2. The file tip of Root ZX lengths was located at $0.85{\pm}0.49mm$ away from the apex in radiograph. 3. The accuracy of the Root ZX was 79.1% within 0.5mm of visual working length and 96.5% within 1.0mm.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.173-173
• /
• 2016

토양유실은 수생태계에 악영향을 미칠 뿐만 아니라 상수원과 수계를 오염시키는 대표적인 오염원으로 간주되고 있다. 이러한 토양유실에 대한 문제를 해결하기 위해서는 무엇보다 토양유실 발생 현황을 파악하는 것이 중요하다. 토양유실 발생 현황을 파악하기 위하여 SWAT, SATEEC, APEX 등 다양한 수문모형 모델들이 개발되어 왔다. 그러나 각각의 수문모형 모델에서 어떠한 토양유실 산정 공식을 사용하였는지에 따라 모의 결과에서 다소 차이를 보이게 된다. 이에 본 연구에서는 우리나라의 필지나 유역을 대상으로 토양유실량을 산정함에 있어 어떠한 공식이 토양유실에 미치는 영향인자를 가장 잘 모의하는지 분석하여 적용하고자 하였다. 본 연구에서는 분지 특성의 유역으로, 유역 내 경작지가 집약적으로 모여 있어 토양유실 문제가 심각한 양구군 해안면 유역을 대상으로 시범 적용하였다. 토양유실량을 모의하기 위한 모델은 USLE, AOF, RUSLE, MUSLE, MUST, MUSS, MUSI의 공식 중에서 사용자가 지정한 공식에 따라 모의가 가능한 APEX 모델로 선정하였다. 본 연구에서는 양구군 해안면의 실측 유량자료를 기반으로 각 공식에 따른 토양유실량에 대하여 검정 작업을 진행하였으며, 이를 양구군 해안면의 토양유실 실측값과 비교 분석하여 해안면 유역에서 토양유실에 미치는 영향인자를 가장 잘 반영할 수 있는 공식이 무엇인지 확인하였다. 본 연구결과를 통해 양구군 해안면 유역에서 발생하는 토양유실량을 예측할 수 있는 최적의 공식을 확인함으로써 토양유실 관련 연구에 기여할 수 있을 것으로 기대된다. 그러나 본 연구에서는 양구군 해안면 유역을 대상으로 최적의 토양유실 산정공식을 찾았지만, 타 유역의 토양유실량을 평가하기에는 한계가 있다. 따라서 APEX를 이용한 전국단위 토양유실량 평가를 통해 범용화 할 수 있는 공식을 찾는 추가적인 연구를 진행한다면 보다 정밀한 토양유실량 산정이 가능하게 되어 향후 우리나라 토양유실 관련 연구에 큰 기여를 할 것으로 기대된다.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.63 no.4
• /
• pp.55-64
• /
• 2021

The expansion of upland crop cultivation in rice paddy fields is recommended by the Korean government to solve the problem of falling rice price and reduction of rice farmer's income due to oversupply of rice. However, water use efficiency is significantly influenced by the land use change from paddy field to upland. Therefore, this study aimed to evaluate the water budget of soybean grown in using APEX (Agricultural Policy and Environmental eXtender) model. The amount of runoff was measured in a test bed located in Iksan, Jeollabu-do and used to calibrate and validate the simulated runoff by APEX model. From 2019 to 2020, the water budget of soybean grown in uplands were estimated and compared with the one grown in paddy fields. The calibration result of AP EX model for runoff showed that R² (Coefficient of determination) and NSE (Nash-Sutcliffe efficiency) were 0.90 and 0.89, respectively. In addition, the validated results of R² and NSE were 0.81 and 0.62, respectively. The comparative study of each component in water budget showed that the amounts of evapotranspiration and percolation estimated by APEX model were 549.1 mm and 375.8mm, respectively. The direct runoff amount from upland was 390.1 mm, which was less than that from paddy fields. The average amount of irrigation water was 28.7 mm, which was very small compared to the one from paddy fields.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.5 no.1
• /
• pp.109-122
• /
• 2002

The purpose of this investigation is to evaluate the effects of the Nuegra on enhancement of the masculine and physical activities in general through measuring changes of the testosterone, FSH and subjective symptoms like fatigue, insomnia, urinary stream, muscular weakness, libido and erectile dysfunction. Total 168 male subjects were enrolled from 12 urology, internal medicine clinics and general practitioner, During the 6-week investigational period, 2 capsules of Nuegra were given to the subjects right after meal for 4 weeks, and 1 capsule of Nuegra was added each time in subjects with no or minimal effect. Testoster-one and FSH levels were measured at first visit and last visit, for evaluating masculine activities. To avoid bias and standardize the test results, only one clinic was assigned as a central lab, and all blood samples were transferred. General information and subjective symptoms were evaluated at first visit and at 2 weeks interval, week 2, 4 and 6 using VAS (Visual Analogue Scale). The mean age of the subjects were 51.8${\pm}$8.2 years old (range: 36.1-82.1). Based on the subjects who were tested on testosterone and FSH levels at day l and week 6, the means were 4.4${\pm}$1.4 nmol/L (range: 2.6-7.7), 8.6${\pm}$9.6 mIU/mL (range: 0.3-40.4), respectively at day 1. At week 6, the results were 4.9 ${\pm}$1.6 (2.6-8.9 range), 9.4${\pm}$13.1 (1.0-53.9 range), respectively. Marginally significant difference between pre-dose and post-dose was present. Statistically significant differences were revealed in general assessment for subjective symptoms, fatigue, insomnia, erectile dysfunction, etc. In fatigue, response rates were 39.6, 65.4 and 76.4% at week 2, 4 and 6, respectively (P < 0.0001). Response vates for erectile dysfunction were 13.4, 41.2 and 72.7% at week 2, 4, and 6 (P < 0.0001), respectively, Response rates for libido were 13.6, 51.6 and 73.5% at week 2, 4, and 6 (P < 0.0001), respectively. For urinary stream response rates were 26.9, 44.7 and 66.8% at week 2, 4, and 6 (P < 0.0001), respectively. VAS for muscular weakness did not show significant results that response rates were 40, 60 and 80% at week 2, 4, and 6 from 8.2 (P ＝ 0.24), respectively. Response rates for insomnia were 50, 60, 100% at week 2, 4, and 6 (P < 0.0001), respectively. The results shows that Nuegra tends to enhance masculine activities including libido, erectile dysfunction and urinary stream and also effective for improving general conditions especially insomnia, muscular weakness and fatigue. In conclusion, this investigation has demonstrated that Nuegra does not only have tendency to increase masculine activities through increased secretion of the testosterone and FSH but also improve general conditions such as erectile dysfunction, libido, fatigue and muscular power.

• The Journal of Advanced Prosthodontics
• /
• v.2 no.3
• /
• pp.92-96
• /
• 2010

PURPOSE. The aim of this study was to evaluate the thickness of buccal and palatal alveolar bone and buccal bony curvature below root apex in maxillary anterior teeth of Korean adults using Cone-beam CT images. MATERIALS AND METHODS. The 3D image was reconstructed with dicom file obtained through CBCT from 20 - 39 year old Korean subjects (n = 20). The thickness of buccal and palatal plate, root diameter, the buccal bony curvature angle below root apex and the distance from root apex to the deepest point of buccal bony curvature were measured on maxillary anterior teeth area using OnDemand3D program. RESULTS. Mean thickness of buccal plate 3 mm below CEJ was $0.68{\pm}0.29\;mm$ at central incisor, $0.76{\pm}0.59\;mm$ at lateral incisor, and $1.07{\pm}0.80\;mm$ at canine. Mean thickness of palatal plate 3 mm below CEJ was $1.53{\pm}0.55\;mm$ of central incisor, $1.18{\pm}0.66\;mm$ of lateral incisor, $1.42{\pm}0.77\;mm$ of canine. Bucco-lingual diameter 3 mm below CEJ was $5.13{\pm}0.37\;mm$ of central incisor, $4.58{\pm}0.46\;mm$ of lateral incisor, and $5.93{\pm}0.47\;mm$ of canine. Buccal bony curvature angle below root apex was $134.7{\pm}17.5^{\circ}$ at central incisor, $151.0{\pm}13.9^{\circ}$ at lateral incisor, $153.0{\pm}9.5^{\circ}$ at canine. Distance between root apex and the deepest point of buccal bony curvature of central incisor was $3.67{\pm}1.28\;mm$ at central incisor, $3.90{\pm}1.51\;mm$ at lateral incisor, and $5.13{\pm}1.70\;mm$ at canine. CONCLUSION. Within the limitation of this study in Korean adults, the thickness of maxillary anterior buccal plate was very thin within 1mm and the thickness of palatal plate was thick, relatively. The buccal bony curvature below root apex of maxillary central incisor was higher than that of lateral incisor and canine and it seems that the buccal bony plate below root apex of central incisor is most curved.