초록 ▼

○ 차세대 중형위성 1호 시스템 요구성능 구체화 및 시스템 구성
- 시스템 요구사항 분석
- 시스템 구성
○ 표준 플랫폼(500kg급) 및 탑재체 시스템 구성 및 개념설계
- 표준 플랫폼 개념설계
- 광학 탑재체 개념설계
- 레이더 탑재체, 마이크로파 탑재체 및 초분광 탑재체 개발 계획 수립
○ 표준 플랫폼 구조체, 추진계 밸브 및 영상압축기능 고속검증보드 선행개발
- 표준 플랫폼 구조체 선행개발
- 추진계 밸브 선행개발
- 영상압축기능 고속검증보드 선행개발
○ 차세대 중형

○ 차세대 중형위성 1호 시스템 요구성능 구체화 및 시스템 구성
- 시스템 요구사항 분석
- 시스템 구성
○ 표준 플랫폼(500kg급) 및 탑재체 시스템 구성 및 개념설계
- 표준 플랫폼 개념설계
- 광학 탑재체 개념설계
- 레이더 탑재체, 마이크로파 탑재체 및 초분광 탑재체 개발 계획 수립
○ 표준 플랫폼 구조체, 추진계 밸브 및 영상압축기능 고속검증보드 선행개발
- 표준 플랫폼 구조체 선행개발
- 추진계 밸브 선행개발
- 영상압축기능 고속검증보드 선행개발
○ 차세대 중형위성 조립, 시험 및 지상국 개발계획 수립 및 개념설계
- 차세대중형위성 조립 및 시험 개념 설계
- 차세대중형위성 지상국 개념 설계

Abstract ▼

IV. Research and Development Results
Section 1. Overview
□ Overview of Project
○ Institute : Korea Aerospace Research Institute
○ Head of Project : Kim Sung-Hoon
○ Period of Project : 2012.12.01 ~ 2014.02.28
○ Objective of Project
: To perform the preliminary study for independe

IV. Research and Development Results
Section 1. Overview
□ Overview of Project
○ Institute : Korea Aerospace Research Institute
○ Head of Project : Kim Sung-Hoon
○ Period of Project : 2012.12.01 ~ 2014.02.28
○ Objective of Project
: To perform the preliminary study for independent development of Compact Advanced Satellite(500Kg class) to efficiently meet the various needs of satellite use
□ Contents of Research
○ shape up the system requirements and organize the system of CAS500
1st satellite
○ organize and conceptual design the standard platform(500kg class) system and the electro-optic payload system of CAS500 1st satellite
○ preliminary study the structure module of standard platform, the valves of propulsion subsystem and the high speed validation board of the satellite image compression function
○ conceptual design the satellite integration and test, and set up the development plan of the ground station
Section 2 S ystem Development
Chapter 1. System Architecture
□ CAS-1 System
- Space Segment
. Satellite 1EA (Spacecraft Bus, Electro Optical Payload)
- Ground Segment
. Ground Station @ KARI site (MCE, IRPE)
. Ground Station @ User site (IRPE)
- Launch Service Segment
. Launch Vehicle and related launch equipment
. Launch Service and Operation
□ Spacecraft Bus
(1) Structure and Mechanism Subsystem
(2) Thermal Control Subsystem
(3) Attitude and Orbit Control Subsystem
(4) Telemetry, Command and Ranging Subsystem
(5) Electrical Power Subsystem
(6) Propulsion Subsystem
(7) Flight Software
□ Payload (Electro Optical Camera)
Chapter 2. System Specification
□ CAS-1 System Specification
Section 3. S tandard Platform Development
Chapter 1. Concept Design for SMS
The design philosophy of CAS500 is to utilize the standard bus structure and the heritages obtained from the experiences of KOMPSAT and GeoKOMPSAT satellites. Also, to maximize the efficiency of integration and the use of space, satellite bus having a square cross section is adopted. In the viewpoint of satellite structure, the primary objective is to develop the standard bus platform able to accommodate various payloads with mass reduction as much as possible. Also, to consider the high agility, the solar array having high stiffness have to be accommodated.
With the aforementioned design philosophy, the conceptual design of CAS500 structure is conducted with the optical payload. Satellite structure is classified with payload module, avionics module, propulsion module, S/C adapter, solar array panels and the deployment device of solar array. Among those, all structures except payload module are kept for other payloads. Two types of solar arrays: deployment/fixation solar array and deployment/rotation solar array can be adopted according the customers' needs.
In the case of the payload module, it can be changed to support payloads and carry out the launch load. The design requirement are decided considering various launch vehicles, stress analysis and stiffness analysis are conducted to check the compliance. From the analysis results, it is confirmed that the structure of CAS500 have sufficient stiffness and the margin of safety higher zero.
From the results, it is verified that conceptual design of CAS500 structure is successfully developed.
Chapter 2. Concept Design for TCS
Conceptual thermal design of CAS500 was performed, characteristics of thermal control subsystems are as below.
- Benchmarking of successful programs such as KOMPSAT-2,3,5 and COMS
- Reliable passive thermal control
- Thermally isolated modules between payload modules and bus module.
- Dedicated radiators for precise thermal control units
- Employ survival heater logic in safe-hold mode for saving heater power
- Simplified heater control logics for low cost/high efficiency
- Employ block type thermal control instead of unit level thermal control
- Exclusion of overheat protection thermostat
- Domestic products for MLI and SSM
- Import products for heater and temperature sensor
- STM thermal vacuum test for verifying preliminary thermal design
- FM thermal vacuum test for verifying overall thermal design
Chapter 3. Concept Design for PS
Conceptual design of CAS500 propulsion system and development of koreanization items were performed.
- Benchmarking of KOMPSAT program heritage
- Trade-off study for commercial propulsion system
- Reliable blowdown monopropellant propulsion system
- Utilization of 1N thruster and removal of redundant branch
- Considering back-up Del-V 5N thruster
- Survey of propulsion system components for low cost and weight reduction
- Conceptual design of pipeline network and manufacturing of test model
- Trace 1N thruster DM development
Chapter 4. Concept Design for AOCS
- Analysis of standard bus model requirements for AOCS concepts design
* Design of AOCS operation mode concepts
* Analysis of AOCS requirements and AOCS performance
* Selection of optimized AOCS sensors and actuators
* Analysis of the AOCS hardware's specifications and requirements
- Establishment of AOCS bus standard model development plan
* AOCS basic design concept development plan
* Agile/Precision AOCS control logic and hardware development plan
* ETB test equipment development plan for AOCS　design's verification
- Agility performance preliminary analysis
* Satellite's moment of inertia and reaction wheel momentum size
* Wheel-based attitude control algorithm
* Agility performance estimation
Chapter 5. Concept Design for EPS
CAS 500 EPS concept design considering required power, performance improvements and installation on satellite was performed EPS component.
Each components concept design is as follows.
1. Power Control & Distribution Unit
- Standard Solar Array Regulator & 28V Regulator
- Core board design for miniaturation/weight lightening
- Box separation method for installation efficiency
(Power Control Unit/Power Distribution Unit)
- Usage of DC/DC converter module which was developed by previous space key technology project.
- Cost reduction methods using commercial parts
2. Solar Array
- Capacity: 1,000W power generation at End of Life
- Peak power voltage: Minimum 60V
- Triple junction GaAs solar cell with minimum 26% efficiency
3. Battery
- Capacity: Minimum 50 Ahr
- Li-ion battery cell with high efficiency power conversion
4. Harness
- Power/Signal interface
Chapter 6. Concept Design for TC&R
The TC&R Subsystem for CAS500 has to develop units which is targeted for koreanization. Those units have the following specification & characteristics.
1. Standard OBC Development
- PCI Based CPU (AT697F) I/F
- Processor Based Fault Detection Logic
- Configurable I/O Module & IP Based CAN, SpW
- DC/DC Converter & Mass Memory which was already developed at Key Technology Projects. (TBD)
2. Digital S-Band Transponder Development
- Frequency: 2025 to 2120 MHz for Rx, 2200 to 230 0MHz for Tx
- Data Rate: up to 4kbps (PCM/BPSK/PM) and 1024kbps (BPSK) for
Demod. up to 128 kbps (PCM/BPSK/PM) and 4Mbps(BPSK) for Mod.
- Ranging: Tone and PN code, RF output power: up to 5W
3. GPS/Galileo Dual Receiver Development
- Frequency: GPS L1 & Galileo E1
- PVT TLM: GPS 1 sec epoch Synchronization, 500msec update interval
- Real-Time Position Accuracy : 10m (TBD)
- 1PPS Output Accuracy : 1.5 usec (TBD)
The Preliminary Study for CAS500 revisited the developed results of
Standard OBC, Digital Transponder, GPS/Galileo Dual Receiver (Dual Receiver
will be used at 3rd Satellite of CAS500 Series). Through this study, the items
for modification and non-complied points was identified.
Chapter 7. Concept Design for FSW
Design of Flight Software based on LEON2
- SPARC v8 Architecture
- AT697F LEON2-FT : AT697E Bug Fix and Functional Improvement
- GRMON
⋅Software Debugging Tool for LEON3
⋅'-leon2' option to be used for AT697F
Improvement of Software Degging/Development Process
- OBCP(On-Board Control Procedure)
⋅On-board Autonomy and Fault Detection/Recovery
⋅Minimize Coupling using Virtual Machine
- Service-Oriented Software Platform
⋅Software Decoupling
⋅Minimize Verification Scopes and Costs
⋅Inter-procedure Communication using Mapper
- Automatic Code Generation for Telemetry Data Acquisition
⋅Reduce Time for Software Change or Modification
Section 4 Payload Development for 500kg class Satellite
Four different Payloads for the 500kg-class satellite shall be developed; Optical payload for accurate earth observation, Microwave Imager for weather/climate forecast, Passive SAR payload for all weather earth observation, Hyperspectral Imager for environmental monitoring.
Chapter 1. Conceptual Design of Optical Payload
1. Major Parameters of Optical Payload for the 500kg-class Satellite
Optical Payload for the 500kg-class Satellite shall have sub-meter resolution, MTF at least 10% and SNR greater than 100. Most critical part for the Optical Payload is to find a CCD detector available.
2. Trade-Off studies of Optical Payload for 500kg-class satellite
Trade-offs were conducted with different combinations of EPD, Pixel pitch, GSD and Focal Length.
Chapter 2. Development of SAR Payload
1. Passive SAR Payload for the 500kg-class satellite
Passive SAR Payload for the 500kg-class satellite shall have sub-meter resolution and an umbrella-type antenna(25kg) instead of phased array antenna(300kg).
[Major Parameters of SAR Payload for 500kg-class satellite]
2. Technology level(Abroad)
- U.S.A., China, Russia, Europe, Canada, Japan, India have been developing and operating SAR satellites.
- Successive cutting-edge SAR technologies were achieved and further development activities are continued.
3. Technology level(Domestic)
- Prototype ground/aircraft SAR payloads have been developed.
- Present TRL is estimated low.
4. Development Plan
- Tight technology control with hardware breakdown (transmitter, receiver, controller, downlink, antenna)
- Successive development for domestic model
- Cooperation between Industries/Universities/Institutes
5. Expectation
- Establishment of SAR payload technology
- International competitiveness of small/lightweight SAR technology
- Procurement of umbrella type antenna technology
Chapter 3. Development of Microwave Payload
1. Passive Microwave Payload for the 500kg-class satellite
Passive Microwave Payload for the 500kg-class satellite shall have resolution 15 km @ 36.5 GHz and swath width 1,516 Km. Conical type was chosen for scan mechanism.
[Major Parameters of Microwave Payload for 500kg-class satellite]
2. Technology level(Abroad)
- American GMI Meteorological satellite(weight 160kg, power 140W) is under development.
- Many passive microwave satellites have been developed and operated; NOAA's MSE series(MSU, AMSU-A, AMSU-B, MHS), SSM/T1, etc.
3. Technology level(Domestic)
- Present TRL is estimated low.
4. Development Plan
- Core technologies needed for Flight Model development should be built up through rigorous research programs.
5. Expectation
- Establishment of core technologies for Microwave payload
Chapter 4. Development of Hyperspectral Imager
1. Hyperspectral Imager for the 500kg-class satellite
Hyperspectral Imager for the 500kg-class satellite shall have spatial resolution 5x5km, spectral resolution 0.16nm and swath width 3,000km.
[Major Parameters of Hyperspectral Imager for 500kg-class satellite]
2. Technology level(Abroad)
- NASA Tempo Environmental satellite is under development.
3. Technology level(Domestic)
- GEMS, Hyperspectral Imager for GEOKOMPSAT-2B is under development.
4. Development Plan
- Core technologies needed for Flight Model development should be built up through rigorous research programs.
- Technologies transferred from the GEMS development shall be utilized.
5. Expectation
- Establishment of core technologies for Hyperspectral Imager and korean industries brought up to provide key parts.
Section 5 Prerequisite Development of Subsystems
Chapter 1. Prerequisite Development of SMS
The preliminary development of CAS(compact advanced satellites)500 standard platform has been conducted based on the design guideline decided from the DM (development model) whose design requirement are almost same with those of conceptual design of FM (flight model) except minor changes considering manufacturing duration and procurement of raw materials. Also, to realize total mass and mass distribution, mass dummies imitating real hardwares were attached to DM. In accordance with the prepared mechanical drawings, manufacturing of structural components were performed. Platforms and panels, which are sandwich-structured, were fabricated by attaching two thin aluminum skins and thick hexagonal aluminum core. Rails, rail fittings, longerons and brackets were made of aluminum though machining process.
Dummy masses were manufactured by stainless steel. Solar array panels are
also sandwich platform made of aluminum skins and core.
To build up the entire structure, individual modules such as avionics module, payload module were assembled independently. When individual module was integrated, firstly, the frame structure was set up with rails, longerons and their fittings. Subsequently, platforms, panels and struts were installed on the frame structure. Finally, DM structure was assembled with payload module and avionics module.
Fixation and separation of solar array was accomplished by the non-explosive assembly and the separation bolts. When it is released, spacecraft is subjected to high-frequency shock, which may cause damage to satellite structure, payloads, avionics and mechanisms. To investigate the shock level due to the separation, its response was measured by accelerometers and DAQ system. From the measurement results, it is confirmed that the acceleration level is not higher than the allowable shock level of the all components therefore satellites could be safe from the shock environment arising from solar array separation. From aforementioned results, it is predicted that CAS500 structure DM could be successfully developed.
Chapter 2. Prerequisite Development of Truster Valve
Conceptual design of CAS500 propulsion system and development of koreanization items were performed.
- Benchmarking of KOMPSAT program heritage
- Trade-off study for commercial propulsion system
- Development of thruster valve DM
Chapter 3. Prerequisite Development of De-Comp. Board
□ NEEDs
Traditional S/W processing would require long duration for the verification of major functions of IDHU
For fast verification of IDHU functions, high-speed decompression of compressed image is essential.
□ PURPOSEs
Replacement of S/W based decompression function of EGSE by H/W
Prerequisite development of ‘High-speed decompression board’
Section 6 Development Plan and Conceptual Design of AIT and Ground Segment in CAS 500 Mission
Chapter 1. Assembly, Integration and Test
Test Plan
- Verification requirement flow down
- Test Classifications
∙ Unit Qualification & Acceptance Test
∙ Structural & Thermal Model(STM) Test
∙ Satellite System Level Test
- Verification Process
- Spacecraft Environmental Testing
∙ Orbit environment test
∙ Electromagnetic environment test
∙ Dynamic environment test
∙ Alignment Measurement
2. Ground Segment
(1) Ground Segment Conceptual Design
- Ground segment configuration consists of mission control system and payload data reception and processing system, which is applied in KOMPSAT missions.
- In CAS 500 mission, ground segment is developed two approaches, one is to utilize proven-design heritage from KOMPSAT missions and the other is to upgrade legacy system with minor changes for multi-mission operability.
Mission Control System
- Antenna System
- Flight Dynamic System
- Satellite Operation System
- Mission Planning System
- Simulation Tool
Payload Data Receiving and Processing System
- Direct Ingestion System
- Image Collection Planning System
- Data Processing System
- Work-order Management System
(2) Development Plan
- From the analysis on technical similarity, in the case of optical sensor payload, entities of ground segment are considerably similar to those of KOMPSAT-3 ground segment. However, in the case of microwave sensor or passive SAR, the similarity is reduced up to 40%
- To cope with low similarity, prototype development in parallel with feasibility study are very needed.
(3) Development Schedule
- Ground segment will be developed according to overall master schedule of PMO (Program Management Office)
- Regarding the changes from legacy ground segment of KOMPSAT mission, reason and scope will be specified in preliminary design review and finalized at critical design review.
S ection 7 CAS 500 Economic Ef f iciency Analysis Research
□ Overview of the Economic Efficiency Analysis Research
○ Title : the Economic Efficiency Analysis Research of the CAS500 program
○ Institute : Korea Institute for Industrial Economics and Trade
○ Head of Research : Ahn Young-Soo
○ Period of Research : 2013.02.01 ~ 2013.08.31
○ Object of Research
: verify the CAS500 program suitability by comparing the social benefit of program with the input budget of program
□ Contents of Research
○ investigate the appropriateness of the CAS500 program development budget and the operation budget
○ draw economic benefit of the CAS500 program
○ analyse the production induction effect, the added value induction effect and the employment creation effect of the CAS500 program
□ CAS500 program budget analysis
○ The budget will be analyzed with consideration of the different development system and the organization of each satellite of CAS500 program
- The standard platform be developed during the 1st and 2nd satellite development program and the standard platform be re-producted without the engineering effort during the 3rd~12th satellite development program
○ The total budget of CAS500 program(12 satellites) is 843.6 billion won
- The budget of the standard platform development stage - the 1st and 2nd satellite development program- is 241.8 billion won and the object of the industry spreading effect analysis is 191.8 billion won excluding the launch and insurance budget
- The total budget of the 3rd~12th satellite development program is 601.9 billion won
□ Results of the industry spreading effect analysis
○ The industry spreading effects of CAS500 program are
∙ production induction effect 1,500 billion won
∙ added value induction effect 424.3 billion won
∙ employment creation effect 9,398 persons
- The industry spreading effects of the standard platform development stage
- the 1st and 2nd satellite development program- are
∙ production induction effect 232 billion won
∙ added value induction effect 142.9 billion won
∙ employment creation effect 3,044 persons
- The industry spreading effects of the 3rd~12th satellite development program are
∙ production induction effect 818 billion won
∙ added value induction effect 281.4 billion won
∙ employment creation effect 6,354 persons
○ The ratio of program cost to effectiveness is 1.32, which shows the CAS500 program has the economic efficiency in the industry spreading effect viewpoint
□ CAS500 1st satellite program B/C analysis result
Remark 1) The expansion possibility of satellite image market is investigated and summarized in several utilized sections(disaster, agriculture, statistics, etc.)
Details are in the Research Report
Section 8 Conclusion
The preliminary study on the development of CAS500 performs
- to set up the development method of CAS500 program
- to analyze the system requirements
- to establish the standard platform development method
- to research the several payloads development method
- to preliminary study the structure module of standard platform, the valves of propulsion subsystem and the high speed validation board of the satellite image compression function
To make efficient development plan
- present the development plan of the BUS platform and the payloads separately
- analyze the required technology, the core technology and the risks of each subsystem
- preliminary study three items to get the core technology
Through this research,
- verify the possibility of CAS500 self-development
- analyze the effects of the development budget reduction and the development period shortening by develope the standard platform
- make the contribution method for the satellite industry advancement by transfer the satellite development technology to the satellite industry
- investigate the possibility of the satellite export

목차 Contents

• 표지 ... 1
• 제출문 ... 3
• 보고서 요약서 ... 4
• 차세대중형위성개발 선행연구 최종보고서 요약문 ... 5
• SUMMARY ... 45
• Table of Contents ... 81
• 목차 ... 83
• 표 차례 ... 87
• 그림 차례 ... 92
• 제 1 장 개 요 ... 98
• 제 1 절 선행연구 배경 및 필요성 ... 99
• 제 2 절 선행연구 추진내용 ... 102
• 제 3 절 예비타당성조사 추진현황 ... 106
• 제 2 장 국내외 기술개발 현황 ... 108
• 제 1 절 국내 위성 개발현황 ... 108
• 제 2 절 국외 위성 개발현황 ... 110
• 제 3 절 분야별 위성개발 동향 ... 112
• 제 3 장 연구개발수행 내용 및 결과 ... 114
• 제 1 절 차세대중형위성 시스템 개발 ... 114
• 1. 차세대 중형위성 시스템 구성 ... 114
• 가. 우주 세그먼트 ... 115
• 나. 지상 세그먼트 ... 119
• 다. 발사 용역 세그먼트 ... 120
• 2. 차세대 중형위성 시스템 요구사항 ... 120
• 제 2 절 차세대중형위성 표준플랫폼 개발 ... 142
• 1. 구조체 개념설계 ... 143
• 가. 표준플랫폼 구조체 설계형상 ... 144
• 나. 표준플랫폼을 적용한 차세대 중형위성형상 ... 146
• 다. 구조해석 ... 148
• 라. 결론 ... 153
• 2. 열 제어계 개념설계 ... 154
• 가. 개요 ... 154
• 나. 열 설계 ... 155
• 다. 하드웨어 ... 159
• 라. Risk assessment & back-up plan ... 160
• 마. STM Test ... 161
• 바. 결론 ... 163
• 3. 추진계 개념설계 ... 164
• 가. 개요 ... 164
• 나. 추진시스템 개념 설계 ... 165
• 다. 국산화 개발 진행 현황 ... 171
• 라. Risk assessment & back-up plan ... 173
• 마. 결론 ... 173
• 4. 자세제어계 개념설계 ... 174
• 가. 표준형 모델 요구사항 분석 ... 174
• 나. 표준형 모델 자세제어계 개발 방안 ... 180
• 다. 기동 성능 예비 해석 ... 186
• 라. 결론 ... 192
• 5. 전력계 개념설계 ... 193
• 가. 전력조절분배장치 개념설계 ... 195
• 나. 태양전지 배열기(Solar Array) 개념설계 ... 203
• 다. 배터리(Battery) 개념설계 ... 204
• 라. DC 하니스(Harness) 개념설계 ... 206
• 6. 원격측정명령계 개념설계 ... 207
• 가. 표준형 OBC 개발 ... 209
• 나. 디지털 트랜스폰더 개발 ... 219
• 다. 3호기부터 적용 예상되는 국산화 GPS/Galileo복합 수신기 개발 ... 222
• 7. 비행소프트웨어 개념설계 ... 225
• 가. LEON2 프로세서 ... 225
• 나. 추가 확보 요소기술 분석 ... 229
• 제 3 절 차세대중형위성 탑재체 개발 ... 233
• 1. 광학탑재체 개념설계 ... 235
• 2. 수동형영상레이더 탑재체 개발계획 ... 255
• 3. 마이크로파 탑재체 개발계획 ... 273
• 가. 수동형 마이크로파 탑재체 기술현황 ... 274
• 나. 수동형 마이크로파 탑재체 ... 279
• 다. 수동형 마이크로파 탑재체 개발 및 기술 확보 전략 ... 282
• 4. 초분광 탑재체 개발계획 ... 286
• 제 4 절 차세대중형위성 부분체 선행개발 ... 304
• 1. 표준플랫폼 구조체 선행개발 ... 304
• 가. 구조설계 ... 304
• 나. 구조체 제작 및 조립 ... 306
• 다. 태양전지판 분리 충격시험 ... 309
• 2. 표준플랫폼 추진계 밸브 선행개발 ... 314
• 가. 개요 ... 314
• 나. 밸브 설계 및 제작 ... 314
• 다. 시험 장치 제작 및 검증시험 ... 316
• 라. 결론 ... 321
• 3. 위성 영상 압축 기능 고속검증보드 선행개발 ... 323
• 가. 개요 ... 323
• 나. 개발내용 요약 ... 324
• 다. 검증 ... 332
• 라. 검토 ... 334
• 제 5 절 차세대 중형위성 조립, 시험 및 지상국 개발계획 수립 및 개념 설계 ... 335
• 1. 차세대 중형위성 조립, 시험 개발계획 수립 및 개념 설계 ... 335
• 가. 시험 계획 수립 ... 335
• 2. 차세대 중형위성 지상국 개발계획 수립 및 개념 설계 ... 347
• 가. 지상국 구성 ... 347
• 나. 개발 방안 ... 354
• 제 6 절 차세대중형위성 경제성분석 연구 ... 356
• 1. 경제성분석 연구의 배경과 목적 ... 357
• 2. 차세대중형위성 개발의 경제성 분석 ... 359
• 가. 경제성분석 방법론 ... 359
• 나. 산업파급효과 분석 ... 361
• 제 7 절 결 론 ... 383
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 384
• 제 5 장 연구개발 결과의 활용계획 ... 387
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 388
• 제 7 장 참고문헌 ... 388
• 끝페이지 ... 389