Development of High Energy Particle Detector for the Study of Space Radiation Storm

조경복,손종대,최정림,이유,민경욱,강석빈,나고운,신구환 한국우주과학회 2014 Journal of Astronomy and Space Sciences Vol.31 No.3

Next Generation Small Satellite-1 (NEXTSat-1) is scheduled to launch in 2017 and Instruments for the Study of Space Storm(ISSS) is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD) is one of the equipment comprisingISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt duringthe event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For thedesign of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement andthe structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of thedetector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on thesimulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placedright in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electronchannel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV,the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detectselectrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the studyon the dynamic mechanism of these particles in the Earth radiation belt will be performed.

정책순응에 요인에 있어 정책집행기관의 매개적 역할

조경복,김성우,정건섭 한국공공관리학회 2012 한국공공관리학보 Vol.26 No.3

본 연구는 정책대상 집단의 순응이 정책목표 달성에 주요한 요소로 판단하고, 이러한 정책순응을 높이기 위한 방안을 모색하고자 하였다. 특히 유사한 사업영역을 가지고 있지만, 관리의 주체 및 법규가 유사한 업종에 있어 규제개혁에 필요한 정책 대상집단의 순응을 확보하기 위한 집행조직의 매개역할을 규명함으로써 정책순응 확보에 있어 일선집행기관의 중요성을 밝히고자 하였다. 분석결과 정책순응에 직접 또는 간접적으로 영향을 미치는 주요변수는 소망성을 나타났고, 다음 정책의 형평성이 차지했다. 소망성은 집행기관에 대한 신뢰성의 증대와 같은 간접적 효과를 통해서도 정책순응에 정(+)의 영향을 나타내는 것으로 분석되었다. 정책결정의 정책대상집단간 자원의 효율적 배분을 나타내는 형평성 측면에서는 정책대상집단의 순응을 직접적으로 확보할 수 있는 수단이기 보다는 집행기관의 신뢰구축을 통한 정책순응을 이끌어내는 간접효과가 크게 작용하고 있는 것으로 밝혀졌다. 정책결정과정의 투명성과 합리성을 나타내는 민주성의 경우 순응에 대한 직접적인 영향관계보다는 정책집행기관의 신뢰성을 통해 정책 순응에 영향을 주는 것으로 나타났다. 정책의 일관성 역시 순응에 직접적인 영향보다는 집행기관의 신뢰를 바탕으로 순응이 확보 되고 있음을 밝혔다.

공유경제 실현을 위한 카쉐어링 이용성과 요인 분석에 대한 연구

정건섭,조경복,김성우 한국비교정부학회 2015 한국비교정부학보 Vol.19 No.3

The study is concerned with Availability and Factor Analysis on Car-Sharing for Sharing Economy with the view of local economy and governance. Accordingly, the relevant theory and references are reviewed, and the survey is performed. The founding of the study can be summarized as follows. According to the survey, it is revealed the more willingness to use car-sharing, as the higher frequency of public transportation availability. Therefore, the policy alternatives should be prepared in near future in order to improve the relation or connection between public transportation and car-sharing; for example, the preparedness of transit system of KTX or bus terminal, etc. Also, the boom of car-sharing industry should be foster based on the reduction of social cost, the increase of confidence, and the realization of social value; which, in turn will be contributed to the construction of collaborative local governance and regional economic development. In this vein, when it comes to urban planning or regeneration, it is desirable to consider the car-sharing from the start phase as small town of city. Lastly, in order for sharing economy to help to realize desirable social values and for car-sharing service to get introduced and developed in local economy, it is necessary to found a car-sharing policy roundtable which should have practical authority and responsibility to play its role in realizing the values of local sharing economy, including social-problem solving, and local economy promotion

Conceptual Design of a Solid State Telescope for Small scale magNetospheric Ionospheric Plasma Experiments

손종대,이재진,조경복,이종길,황정아,박재흥,곽영실,박원기,남욱원,독고경환 한국우주과학회 2018 Journal of Astronomy and Space Sciences Vol.35 No.3

The present paper describes the design of a Solid State Telescope (SST) on board the Korea Astronomy and Space Science Institute satellite-1 (KASISat-1) consisting of four [TBD] nanosatellites. The SST will measure these radiation belt electrons from a low-Earth polar orbit satellite to study mechanisms related to the spatial resolution of electron precipitation, such as electron microbursts, and those related to the measurement of energy dispersion with a high temporal resolution in the sub-auroral regions. We performed a simulation to determine the sensor design of the SST using GEometry ANd Tracking 4 (GEANT4) simulations and the Bethe formula. The simulation was performed in the range of 100 ~ 400 keV considering that the electron, which is to be detected in the space environment. The SST is based on a silicon barrier detector and consists of two telescopes mounted on a satellite to observe the electrons moving along the geomagnetic field (pitch angle 0°) and the quasi-trapped electrons (pitch angle 90°) during observations. We determined the telescope design of the SST in view of previous measurements and the geometrical factor in the cylindrical geometry of Sullivan (1971). With a high spectral resolution of 16 channels over the 100 keV ~ 400 keV energy range, together with the pitch angle information, the designed SST will answer questions regarding the occurrence of microbursts and the interaction with energetic particles. The KASISat-1 is expected to be launched in the latter half of 2020.

Improving the Accuracy of a Heliocentric Potential (HCP) Prediction Model for the Aviation Radiation Dose

황정아,윤경원,조경복,노성준 한국우주과학회 2016 Journal of Astronomy and Space Sciences Vol.33 No.4

The space radiation dose over air routes including polar routes should be carefully considered, especially when space weather shows sudden disturbances such as coronal mass ejections (CMEs), flares, and accompanying solar energetic particle events. We recently established a heliocentric potential (HCP) prediction model for real-time operation of the CARI-6 and CARI-6M programs. Specifically, the HCP value is used as a critical input value in the CARI-6/6M programs, which estimate the aviation route dose based on the effective dose rate. The CARI-6/6M approach is the most widely used technique, and the programs can be obtained from the U.S. Federal Aviation Administration (FAA). However, HCP values are given at a one month delay on the FAA official webpage, which makes it difficult to obtain real-time information on the aviation route dose. In order to overcome this critical limitation regarding the time delay for space weather customers, we developed a HCP prediction model based on sunspot number variations (Hwang et al. 2015). In this paper, we focus on improvements to our HCP prediction model and update it with neutron monitoring data. We found that the most accurate method to derive the HCP value involves (1) real-time daily sunspot assessments, (2) predictions of the daily HCP by our prediction algorithm, and (3) calculations of the resultant daily effective dose rate. Additionally, we also derived the HCP prediction algorithm in this paper by using ground neutron counts. With the compensation stemming from the use of ground neutron count data, the newly developed HCP prediction model was improved.

제 1 발표장 : 경사기능 지르코니아 단열피복층의 제조

박차완,박익민,조경복,정명규 한국복합재료학회 1997 한국복합재료학회 학술발표대회 논문집 Vol.- No.1

II급 부정교합에서 컴퓨터단층촬영을 이용한 아래턱뼈의 삼차원 형태연구

이우영,박대균,황순정,조경복,한승호 대한체질인류학회 2004 해부·생물인류학 (Anat Biol Anthropol) Vol.17 No.3

In case of class II malocclusion, mandible has morphological characteristics such as size and position. To investigate morphological characteristics of mandible, most study has been done in indirect measurement using cephalogram. Recently, it is possible to measure directly Three dimensional skeletal model reconstructed from computed tomography images. This study aimed to know characteristics of mandible in class II malocclusion, analyzing Three dimensional mandible models of class I and II malocclusion which are acquired from computed tomography images of 80 cadavers. In open bite type of class II malocclusion, the size of mandible had no difference from class I malocclusion but the sagittal ramus angle and condylar angle were smaller 3 degree than class I. These findings inform that the ramus and condylar process of open bite type of class II malocclusion stand more erectly than class I and then the mandible is placed posteriorly. In deep bite type of class II malocclusion, the length of mandible was shorter 4 mm and, the sagittal ramus angle and condylar angle were larger 5 degree than class I. These findings, short length of mandible and more lying ramus and condylar process, make the mandible in the feature of deep bite of class II malocclusion. In comparison of past issued articles which used cehpalometry mainly, the values of measurements agree partially. It is the differences of measuring points and methods to make inconsistency between indirect measurement like cephalometric study and 3 dimensionally direct measurement like this study. To increase accuracy of Three dimensionally direct measurement, standardization of measuring points and method for the measurement is required. II급 부정교합은 유전적인 요인 외에 위턱뼈의 과성장, 아래턱뼈의 열성장, 아래턱뼈의 아래뒤쪽 회전과 같은 많은 요소들이 그 원인으로 언급되어 왔으며 또한 II급 부정교합의 뼈대형태에 대한 연구에서는 아래턱뼈가 머리뼈바닥에 대해 뒤쪽에 위치하며 아래턱평면과 머리뼈바닥 사이의 각도는 정상교합보다 큰 것으로 보고되었 다. 현재까지 아래턱뼈에 대한 형태분석은 주로 머리방사선사진계측(cephalometry)과 같은 간접계측에 의한 다양 한 계측법과 분석방법이 나와 있다. 그러나 머리방사선사진계측은 머리뼈의 중첩된 이미지를 이용하므로 좌∙우 의 서로 다른 특징을 구별하기 힘들며 얼굴뼈와 아래턱뼈의 관계를 육안적으로 파악할 수 없는 제한성이 있다. 따 라서 보다 정확한 부정교합의 양상과 얼굴의 형태를 알기 위해서는 삼차원적인 마른뼈 또는 그 모델을 통한 직접 계측이 필요하며 II급 부정교합의 경우, 아래턱뼈에 대한 직접계측이 이루어져야 할 것이다. 이에 본 연구는 한국 인 시신 80구를 대상으로 컴퓨터단층촬영을 한 뒤 시상면에서의 영상을 통해 II급 부정교합을 분류하고 삼차원으 로 재구성된 아래턱뼈 모델을 직접 계측하여 II급 부정교합에서 아래턱뼈의 형태학적 특징을 알아보았다. 삼차원 계측을 이용하여 부정교합에 따른 아래턱의 형태를 비교한 결과, II급 부정교합 중 개교합(open bite)인 경우는 I 급 부정교합의 아래턱에 비해 크기 차이는 없으며 시상면턱뼈가지각과 시상면관절돌기각에서 각각 3정도씩 작 아 I급 부정교합보다 아래턱이 뒤쪽에 위치함을 알려주었다. II급 부정교합 중 과개교합(deep bite)인 경우는 I급 부정교합에 비해 아래턱뼈길이가 4 mm 정도 짧은 대신 시상면턱뼈가지각과 시상면관절돌기각이 각각 5정도씩 커서 I급 부정교합에 비해 과개교합을 이루게 하며 아래턱뼈의 길이는 짧아 아래턱이 상대적으로 뒤쪽에 위치하 는 II급 부정교합을 이루는 것으로 생각한다.

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

손종대,이재진,민경욱,이준찬,이승욱,이대영,조경복,이유,나고운,강경인,신구환 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.9

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0 ◦, 45 ◦, and 90 ◦, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from ~ 350 keV to ~ 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.