지역적인 GPS 관측 데이터를 이용한 이온층 모델링 및 추정

황유라 ( Yoo La Hwang ),박관동 ( Kwan Dong Park ),박필호 ( Pil Ho Park ),임형철 ( Hyung Chul Lim ),조정호 ( Jeong Ho Joh ) 大韓遠隔探査學會 2003 大韓遠隔探査學會誌 Vol.19 No.4

이온층 구면을 사각형 격자로 분할하여 각 격자에서 총전자수를 추정하는 지역적 GPS 이온층 모델을 제시한다. 한반도 상공을 위도와 경도 1°×1°의 공간해상도를 가진 격자로 구분하고 칼만 필터(Kalman filter)를 이용하여 격자 상의 총전자수를 추정하였다. 이 연구를 위해 한국천문연구원에서 운영하고 있는 전국 규모의 9개 GPS 상시 관측소의 데이터를 이용하였다. 수신된 의사거리 데이터의 측정 잡음을 줄이기 위해 의사거리와 반송파 위상 데이터를 선형 조합한 위상보정 의사거리(phase-leveled pseudorange) 데이터를 새롭게 만들어 사용하였다. 또한 지역적 이온층의 변화에 적합한 태양-지자기 좌표계(solar-geomagnetic reference frame)를 이용하였다. 태양 활동이 비교적 활발하지 않은 때의 경우, 이 연구의 모델은 이온층 활동이 활발한 낮 시간대의 총전자수가 대략 30-45 TECU 정도로 나타났다. 이 모델의 신뢰성을 평가하기 위해 한국전문연구원(Korea Astronomy Observatory, KAO)의 지역적 모델과 Center for Orbit Determination in Europe의 전 지구적 모델에 의한 총전자수를 동일 지역에 대해 비교했을 때 5일 동안 약 4-5 TECU 정도의 RMS 차이를 보였다. We present a GPS-derived regional ionosphere model, which estimates Total Electron Content (TEC) in a rectangular grid on the spherical shell over Korea. After dividing longitude and latitude over Korea with 1˚×1˚ spatial resolution, the TEC at the vertex of the grid was estimated by the Kalman filter. The GPS data received from nine nationwide GPS stations, operated by Korea Astronomy Observatory (KAO), were used for this study. To reduce inherent noises, the pseudorange data were phase-leveled by a linear combination of pseudoranges and carrier phases. The solar-geomagnetic reference frame, which is less variable to the ionosphere movement due to the Sun and the geomagnetic field than an Earth-fixed frame, was used. During a quiet time of solar activity, the KAO`s regional ionosphere map indicated 30-45 Total Electron Content Unit at the peak of the diurnal variation. In comparison with the Global Ionosphere Map of the Center for Orbit Determination in Europe, RMS differences were at the level of 4-5 TECU for five days.

Application of ED-XRF Measurement on Uranium Contaminated Soil Waste for Regulatory Clearance

Mal-Go-Bal-Gae-Bit-Na-La Yoo,Ji-Young Park,Jong-Myoung Lim,Won-Hyuk Jang,Dae-Seok Hong 한국방사성폐기물학회 2019 한국방사성폐기물학회 학술논문요약집 Vol.2019 No.10

Tunable Metamaterial Absorber Using Ferromagnetic Resonance

La Yunju,Jeon Ok Sung,Lee Young Jun,Park Sang Yoon,Yoo Young Joon,Lim Taekyung,Yang KeunHyeok 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.11

We simulated a study on a tunable metamaterial absorber using ferrite rubber as a dielectric substrate with ferromagnetic properties. The proposed structure employs ferromagnetic resonance, which utilizes the coupling of an applied magnetic field and an incident electromagnetic wave. As the magnitude of the applied magnetic field increases, it can be seen that the absorption peak moves to a higher frequency. The adjustment of the absorption frequency using the proposed method is expected to be applied to various fields such as sensors, electronic devices and 5G communication antennas.

Metamaterial’s Acceptable Level of Wrecked Meta-pattern

La Yunju,Jeon Ok Sung,Lee Young Jun,Park Sang Yoon,Yoo Young Joon,Lim Taekyung,Yang Keun-Hyeok 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.11

The periodic arrangement in metamaterial (MM) should be maintained to ensure the extraordinary properties, but how much periodic irregularity is allowed generally without degrading the properties is not only important for the tolerance in fabrication but interesting scientifically. We introduce the wrecked effect in MM utilizing perfect MM absorber in visible and GHz ranges. The original perfect MM properties turn out to be maintained until MM is destroyed to 10%. In the view of MM absorber, even 40% broken meta-pattern are still good for absorption higher than 93%, the criterion for perfect absorption. The wrecked pattern over 80% result in absorption of nearly 50% in both simulation and experiment, which is even higher than expected. These results can lead to broad applications at the present and in near future through more convenient and cost-effective research and development on MMs.

Effects of Elevated Sublethal Temperature on Polyamine Metabolism in Testis of Helicoperpa assulta

Yoo, Chong-Myung,Kim, Sun-Hui,La, Yoon-Heum,Jeong, Seong-Eun 한국곤충학회 1998 Entomological Research Vol.28 No.3

담배나방(Helicoverpa assulta)정소에서의 polyamine 대사에 미치는 상승아치사온도의 영향을 알아보기 위해 상승아치사온도($33{\pm}1^{\circ}C$)와 적정발생온도($25{\pm}1^{\circ}C$)에서의 용-성충발생 동안 정소의 수분함량과 주요 polyamine류의 함량 및 Putrescine 합성효소의 활성도를 분석하였다. 상승온도의 처리는 putrescine 합성효소인 ODC (ornithine decarboxylase)와 ADC(arginine decarboxylase)의 활성도에 명확한 영향을 나타내었으며, 이에 따라 일부 polyamine 대사물의 수준에서도 변화가 관찰되었다. 분석된 대사물 가운데 polyamine류의 diamine precusor인 putrescine에 대한 영향이 가장 현저하였으며, spermidine에 대한 영향은 매우 미미하였다. 상승온도의 처리에 의한 용초기의 putrescine 함량 증가는 ODC는 물론 ADC의 활성도 증가와도 coupled되어 나타났다. 그러나 Putrescine의 수준이 현저히 supressed되는 용말기 이후에 ODC의 활성이 다시 한번 크게 peak를 나타내었는데 비해 ADC의 활성은 계속 낮은 수준을 유지하여, putrescine수준과의 상관성이 없이 일어나는 ODC활성도의 증가에 대한 의문과 함께 ADC가 적어도 어느 국한된 시기동안에는 putrescine 성에서 주도성을 갖음에 대한 가능성이 시사되었다. 주목할만한 정소 spermidine에 대한 영향은 나타나지 않았으나, 초기에 주요 polyamine류 가운데 가장 낮은 수준을 보이는 spermine에 대한 고온의 영향은 뚜렷히 나타났다. $33{\pm}1^{\circ}C$에서 정소의 총 spermine함량이 적정온도에서는 감소하는 현상과는 반대로 용1일과 3일에서 증가하였으나, 이때 생체량당 함량은 동시기에 일어나는 정소의 hydration에 따라 명확한 변화를 보이지 않았다. Effects of the elevated sublethal temperature on polyamine metabolism in testis were investigated by analyzing the water content, contents of major polyamines, and activities of the rate-limiting enzymes for putrescine synthesis during the pupal-adult development at the elevated temperature ($33{\pm}1^{\circ}C$) and the optimal temperature ($25{\pm}1^{\circ}C$) in Helicoverpa assulta. The elevated temperature affected evidently the activities of the enzymes acting on putrescine synthesis, ODC (ornithine decarboxylase) and ADC (arginine decarboxylase), and consequently some polyamine metabolites showed the reliable altered levels. The effect was the most remakable on putrescine, the diamine precusor of polyamines, but it was very slight on spermidine among the examined metabolites. At the early pupal stage, the induced increase in putrescine content by the elevated temperature was coupled with the increases in enzyme activity of ADC as well as ODC. The ODC activity, however, was suspiciously peaked up again, while the ADC was kept in low activity continually after the late pupal stage when the putrescine level is highly suppressed, bringing up a question of the conflicting increase in ODC activity and at the same time suggesting that ADC possibly functions primarily in putrescine synthesis at least during a certain restricted period. Any considerable effects on spermidine was not confirmed, but spermine, the lowest constituent of the major polyamines, was affected somewhat by the high temperature. The total amount of spermine in testis increased at 1- and 3-day old pupa at $33{\pm}1^{\circ}C$ in contrary to the decreasing trend at $25{\pm}1^{\circ}C$, but the content/wet weight was not altered obviously because of the testis' hydration during the period.

소세포 폐암의 갑상선전이 1예

장리라,최영식,박요한,문대성,김자경,김성은,최인수,유찬희,남성진 고신대학교 의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.3

Metastasis to the thyroid gland is usually considered uncommon. The most frequent sites of the primary tumor include the kidney, breast and lung. Its presence often indicates poor prognosis. Metastases represent the advanced stage of the tumors and fine needle aspiration cytology is and important way of diagnosis in thyroid metastasis. we experienced a case of Metastatic Small cell Lung Carcinoma to the Thyroid Gland. A 58-year-old man with Graves' disease diagnosed pulmonary nodule in the left upper lung field on his chest X-ray film. The patient's thyroid gland was diffusely swollen, and elastic to hard. A thyroid ultrasonography showed 1cm sized hypodense nodule on the left thyroid gland. The patient underwent a ultrasonography guided fine needle aspiration cytology of the mass. Cytological diagnosis was a metastatic small cell carcinoma. Then Chemotherapy was administered to the patient. The authors report this rare case of metastatic small cell lung carcinoma to the thyroid with literature review.

어린이들의 텔레비전 視聽習慣에 對한 調査硏究

유미라,정문주 이화여자대학교 체육대학 1970 梨花體育學會誌 Vol.- No.4

① 3년 이상 본 어린이가 67%이다. ② 2시간 정도 보는 어린이가 거의 반을 차지하고 있다. ③ 1시간 정도 연속적으로 보는 어린이가 약 50%를 차지하고 있다. ④ 불을 끄지 않고 보는 어린이가 약 80%, 끄고 보는 어린이가 약 20%이다. ⑤ 17~19인치 이상의 테레비를 가지고 있는 어린이가 86%를 차지하고 있다. ⑥ 테레비 세트 높이가 같다는 어린이가 60%로 가장 많이 차지하고 있는 반면 높다와 낮다도 각각 20%를 차지하고 있다. ⑦ 약 73%에 해당하는 어린이가 2~3m의 거리에서 보는 경향이다. ⑧ 약 60%에 해당하는 어린이가 보안 장치가 있는 테레비를 시청하고 나머지 40%의 어린이들이 그 반대의 경우이다. ⑨ 방바닥에 앉아서 보는 어린이가 약 60%를 차지하고 있고 엎드리고 누운자세에서 보는 어린이도 약 15%에 해당한다. ⑩ 대부분의 어린이가 괜찮다고 대답하고 있다. ⑪ 약 78%에 해당하는 어린이가 괜찮다의 반응을 보이고 있는가 하면 약 23%에 해당하는 어린이가 아프다라고 대답하고 있다. ⑫ ⑪에서 꼭같은 반응을 보여주고 있다. ⑬ 약 70%에 해당하는 어린이가 테레비를 본 후에 피로하다는 반응을 보이고 있다. ⑭ 하루 1시간 이하 밖에서 노는 어린이가 약 50%를 차지하고 있다. ⑮ 대부분의 어린이가 알맞는 수면시간을 확보하고 있다.

Does Adding Diffuse Optical Tomography to Sonography Improve Differentiation Between Benign and Malignant Breast Lesions? : Observer Performance Study

La Yun, Bo,Kim, Sun Mi,Jang, Mijung,Ahn, Hye Shin,Lyou, Chae Yeon,Kim, Mi Sun,Kim, Sun Ah,Song, Tai-Kyong,Yoo, Yangmo,Chang, Jin Ho,Kim, Youngmi American Institute of Ultrasound in Medicine 2015 Journal of ultrasound in medicine Vol.34 No.5

<P>Objectives-The purpose of this study was to investigate the added value of diffuse optical tomographic categories combined with conventional sonography for differentiating between benign and malignant breast lesions. Methods-In this retrospective database review, we included 145 breast lesions (116 benign and 29 malignant) from 145 women (mean age, 46 years; range, 16-86 years). Five radiologists independently reviewed sonograms with and without a diffuse optical tomographic category. Each lesion was scored on a scale of 0% to 100% for suspicion of malignancy and rated according to the American College of Radiology Breast Imaging Reporting and Data System classification. Diagnostic performance was analyzed by comparing area under receiver operating characteristic curve values. Reader agreement was assessed by intraclass correlation coefficients. Results-In the multireader multicase receiver operating characteristic analysis, adding a diffuse optical tomographic category to sonography improved the diagnostic accuracy of sonography (mean areas under the curve, 0.923 for sonography alone and 0.969 for sonography with diffuse optical tomography; P = .039). The interobserver correlation was also improved (0.798 for sonography alone and 0.904 for sonography with diffuse optical tomography). The specificity increased for 4 reviewers from a mean of 19.5% to 45.8% (P < .001 for reviewers 1-4; P = .238 for reviewer 5) with no significant change in the sensitivity. When the diffuse optical tomographic category was applied strictly, the specificity increased for all reviewers from a mean of 19.5% to 68.3% (P < .001 for all reviewers) with no significant change in the sensitivity. Conclusions-The addition of diffuse optical tomographic categories to sonography may improve diagnostic performance and markedly decrease false-positive biopsy recommendations.</P>

A Preliminary Implementation Study of TDMA-based Positioning System Utilizing USRP and GNU Radio

Yoo, Won Jae,Choi, Kwang Ho,Lim, JoonHoo,Kim, La Woo,So, Hyoungmin,Lee, Hyung Keun The Institute of Positioning 2017 Journal of Positioning, Navigation, and Timing Vol.6 No.3

Positioning signals transmitted by Global Positioning System (GPS) satellites located at approximately 20,000 km height is very weak. For the reason, GPS signals are vulnerable to intentional jamming and unintentional disturbance. Recently, the number of jamming has been increased significantly all over the world. For the applications where continuous and reliable positioning is required when GPS jammers are activated, other positioning systems are strongly required. In this work, a set of Time Division Multiple Access (TDMA)-based transmitters and receivers utilizing Universal Software Radio Peripheral (USRP) and GNU Radio are designed and implemented. To eliminate the undesirable effects of GPS jamming, a frequency band which does not overlap L band is utilized. To demonstrate the accuracy of the proposed method, an experiment was performed.

고강도 강관말뚝의 항타후 구조성능 분석

나승민(La SeungMin),유한규(Yoo Hankyu) 대한토목학회 2011 대한토목학회논문집 C Vol.31 No.6

강관말뚝은 오랫동안 다양한 깊은 기초에 적용되어 왔으나 최근 강재가격의 상승으로 균질한 품질 큰 강성 용이한 시공 등의 장점에도 불구하고 기술자들이 자유롭게 적용 못하고 있다. 그러므로 강관말뚝으로 시공할 경우에는 초기 항타후 계획 고 이상에서 절단된 강관을 재활용할 수 있다면 공사비를 절감하는데에 기여할 수 있다. 이러한 사유로 인하여 시공자들은 항타후 절단된 강관말뚝을 새롭게 시공할 말뚝과 함께 시공하고자 하나 명확한 정량적인 항타후 강관말뚝의 거동특성의 부재 및 재활용을 위한 적절한 대응방법과 기준의 부재로 인하여 말뚝의 건전도 문제 문제 발생시의 대응방법 부재 등이 실제 현장에서 종종 발생하고 있다. 본 연구에서는 신규 강관말뚝과 사용자 하중 또는 극한 하중을 받은 강관말뚝에 대하여 현장에서 수행한 말뚝 동재하시험과 실내에서의 피로시험 인장시험 샤르피 충격시험을 실시하여 그 결과를 비교분석하였다. 시험결과로부터 허용응력 수준의 항타응력이 발생한 사용 하중조건에서는 항복강도의 변화가 2% 이하이며 최대 허용항타응력(0.9σy)을 항타횟수가 3000회까지 받은 극한 하중조건에서는 항복강도의 변화가 5% 이하인 것을 확인할 수 있다. 또한 각 변수의 민감도를 확인하기 위하여 통계분석을 실시하였다. 모든 실험결과로부터 강관말뚝의 재활용 가능여부에 대한 판단 기준은 항복강도의 변화 보다는 오히려 샤르피충격에너지 용접부에서의 강도변화 및 품질관리 강관의 단면 변화 항타후 강관의 국부좌굴에 기인하는 것을 확인할 수 있었다. Steel pipe piles have been used as various deep foundation materials for a long time. Recent increase in steel material cost has made engineers reluctant in using it even with its good quality and ease of construction. Therefore when constructing with steel pipe pile the decision to reuse the excessive pile length that is cut off from the designed pile head elevation after pile driving can be cost saving. This has caused many constructors to reuse the pile leftovers with new piles but the absence of quantitative structural capacity behaviors of steel pipe pile after pile driving or appropriate countermeasures and standards in reusing steel pipe pile has resulted in wrong applications pile structural integrity problems inappropriate limitation of reusable pile length etc. The structural performance analysis between a new pile and a pile that has undergone working state and ultimate state stress level during pile driving was performed in this research by means of comparing the results between the dynamic pile load test tensile load test charpy energy test and fatigue test for high strength steel of 440N/㎟ yield strength. Test results show that under working load conditions the yield strength variation is less than 2% and for ultimate load conditions the variation is less than 5% for maximum total blow count of 3000. The results have been statistically analyzed to check the sensitivity of each factors involved. From the test results reusability of steel pipe pile lies not in the main pipe yield strength deviation but in the reduction of absorb energy strength changes and quality control at the welded section shape deformation and local buckling during pile driving.