• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.5
• /
• pp.1104-1109
• /
• 2015

Due to the rapid growth in digital contents, it is important for us to design a high speed and secure encryption algorithm which is able to comply with the existing and future needs. This paper proposes an alternative approach for self-decimated LM-128 summation sequence generator, which will generate a higher throughput if compared to the conventional generator. We design and implement a threshold clock-controlled LM-128 and prove that it has a lower clock cycle and hence giving a higher key stream generation speed. The proposed threshold clock-control LM-128 generator consists of 256 bits inner state with 128 bits secret key and initialization vector. The cipher achieves a security level of 128 bits to be adapted to the digital contents security with high definition and high quality.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.1011-1014
• /
• 2004

본 논문에서 제안된 Self_Decimated LM-128 키 수열 발생기(Keystream generator)는 2개의 비트 메모리 합산 수열발생기(summation generator)를 갖는 자체 클럭 조절형 키 수열 발생기(stream cipher)이다. Self_Decimated LM-128은 LM 계열에서 제시된 특수한 암호로 128비트 키와 128비트 초기 벡터 그리고 257 비트의 내부 상태를 가지며 128 비트의 보안 레벨을 유지한다. 알려진 보안 분석의 공격에 대비해서 2-비트 메모리를 이용한 합산 수열발생기와 자체 클럭 조절형 키 수열 발생기를 포함한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.893-896
• /
• 2006

최근의 통신망의 급격한 발전으로 디지털 콘텐츠 분야에서도 고화질/고용량으로 변모하고 있으며, 이러한 환경속에서 콘텐츠의 안전한 보호를 위한 고비도, 고속화 및 고신뢰도 암호 알고리즘의 설계가 요구되고 있다. 본 논문에서 제안된 Threshold clock-controlled LM은 클럭 조절형 암호 알고리즘의 클럭 최대 주기를 최소화시켜 키 수열의 발생 속도를 향상 시켰으며 128비트 키, 128 초기화 백터, 그리고 257 비트의 내부 상태를 가지며, 128-비트의 보안 레벨을 유지함으로써 안전성이 보장되어 고화질/고용량의 디지털 콘텐츠 보호에 적합함을 알 수 있다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.663-665
• /
• 2009

Ubi-Home 환경에서 장치제어를 하기위해 다양한 방법이 제안되었다. 그 중 원격지에서 장치제어를 하기 위해 특정 기기(로봇)를 활용할 수 있다. 하지만 이와 같은 방법에는 로봇과 장치들의 위치인식과 이동경로 설정에 따른 제약사항이 따른다. 또한 이러한 위치인식 및 이동에는 미리 작성된 하나의 맵이 사용되므로 새로운 환경의 변화나 확장에 적용할 수 없다. 따라서 본 논문에서는 로봇과 장비의 위치인식과 이동경로를 위한 학습형 맵 작성 기법을 제안하며, 테스트를 위해 Atmega128v4 MCU와 AX-12+ Motor, AX-S1 Sensor, ZBS-200 Zigbee, CL-1L5/603LM Infrared Ray Sensor로 로봇을 제작하여 실내 환경 모형에서 테스트하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.2
• /
• pp.121-128
• /
• 1998

A new magnetic ballast was designed and developed to get high luminous efficiency. The core material of new magnetic ballast was G-9 and its shape of core is modified. The diameter of the coil was upgraded to 0.5[mm], and a new power-saving circuit was designed for the semiconductor ignition starter. The experimental results of the ballast showed reduction of the electric loss in the magnetic ballast about 1.7Watt (0.5[%]). The luminous efficiency was increased by 6.2 lm/Watt (7.6[%]) and the ballast efficiency factor(BEF) of 1.09(7.6[%]). The prototype was tested through national standard testing procedure. A high efficient energy-using equipment (the second grade in the efficiency of energy consumption) was certified. The saving power of 1.7[W] was shown by lighting appratus for fluorescent lamps. The result will be used for the high efficient magnetic ballast technology.nology.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.276-279
• /
• 2003

본 논문에서는 블루투스 장비 간 암호화를 위해 사용되는 암호화 모듈의 설계 및 구현에 관한 내용을 다룬다. 암호화 모듈은 기저 대역내에 암호화 키 생성 모듈과 암호화 엔진 모듈로 구성된다. 암호화 키 생성 모듈은 Cylink사에서 제안한 공개 도메인인 SAFER+(Secure And Fast Encryption Routine) 알고리즘을 사용하여 128bit 키를 생성한다. 그 구성은 키 치환을 위한 치환 함수(key-controlled substitution)와 선형 변환을 위한 PHT(Pseudo-Hadamard Transform)와 Armenian Shuffle 변환기로 구성된다. 암호화 엔진 모듈은 전송 패킷내의 페이로드 데이터와 생성된 사이퍼 키 스트림 데이터와 XOR연산을 통하려 암호화를 행하며 그 구성은 LFSR (Linear Feedback Shift Register)와 합 결합기로 구성된다. 이 중 암호화 키 생성 모듈은 LM(Link Manager)의 PDU(Protocol Data Unit) 패킷을 통해 상호 정보가 교환되므로 암호화키를 생성하는데 있어 시간적 제약이 덜 하다. 따라서 본 논문에서는 변형된 SAFER+ 알고리즘 구현하는데 있어 치환 함수의 덧셈과 XOR, 로그, 지수연산을 바이트 단위의 순차 계산을 수행함으로써 소요되는 하드웨어 용량을 줄이도록 설계하였다. 본 논문에서 제시한 모듈은 블루투스 표준안 버전 1.1에 근거하여 구현하였으며 시뮬레이션 및 테스트는 Xilinx FPGA를 이용하여 검증하였다.

• Korean Journal of Materials Research
• /
• v.21 no.5
• /
• pp.250-254
• /
• 2011

We have synthesized bluish-green, highly-efficient $BaSi_2O_2N_2:Eu^{2+}$ and $(Ba,Sr)Si_2O_2N_2:Eu^{2+}$ phosphors through a conventional solid state reaction method using metal carbonate, $Si_3N_4$, and $Eu_2O_3$ as raw materials. The X-ray diffraction (XRD) pattern of these phosphors revealed that a $BaSi_2O_2N_2$ single phase was obtained. The excitation and emission spectra showed typical broadband excitation and emission resulting from the 5d to 4f transition of $Eu^{2+}$. These phosphors absorb blue light at around 450 nm and emit bluish-green luminescence, with a peak wavelength at around 495 nm. From the results of an experiment involving Eu concentration quenching, the relative PL intensity was reduced dramatically for Eu = 0.033. A small substitution of Sr in place of Ba increased the relative emission intensity of the phosphor. We prepared several white LEDs through a combination of $BaSi_2O_2N_2:Eu^{2+}$, YAG:$Ce^{3+}$, and silicone resin with a blue InGaN-based LED. In the case of only the YAG:$Ce^{3+}$-converted LED, the color rendering index was 73.4 and the efficiency was 127 lm/W. In contrast, in the YAG:$Ce^{3+}$ and $BaSi_2O_2N_2:Eu^{2+}$-converted LED, two distinct emission bands from InGaN (450 nm) and the two phosphors (475-750 nm) are observed, and combine to give a spectrum that appears white to the naked eye. The range of the color rendering index and the efficiency were 79.7-81.2 and 117-128 lm/W, respectively. The increased values of the color rendering index indicate that the two phosphor-converted LEDs have improved bluish-green emission compared to the YAG:Ce-converted LED. As such, the $BaSi_2O_2N_2:Eu^{2+}$ phosphor is applicable to white high-rendered LEDs for solid state lighting.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.7 no.2
• /
• pp.128-134
• /
• 2008

Purpose: We prospectively evaluated the clinical usefulness of the patellar inferior pole (PIP) as a landmark of the anteromedial (AM) portal for the arthroscopic surgery of the medial mensiscus posterior horn (MMPH). Materials and Methods: Group 1 (50 normal left knees of adults), Group 2 (10 normal knees under anesthesia), and Group 3 (50 consecutive knees undergoing elective arthroscopic surgery for relatively simple intraarticular pathologies, or diagnostic arthroscopy) were included. In Group 1 and 2, the true lateral (A) and valgus stress lateral radiographs (B) on $30^{\circ}$ flexion were obtained, and the lines (AM portal line) passing through the PIP and distal-most medial femoral condyle (MFC) were drawn under the condition without considering the thickness of articular cartilage of MFC (1, 2-A, B group), and considering it as 2.5mm on B (1, 2-C group). Then, we investigated the meeting point of the AM portal line with medial tibial plateau (C-D percentage), and measured the distance between the PIP and the anterior joint line (E-length), and medial tibial-femoral joint space (F-length). In Group 3, the AM portal was made at the PIP level and clinical usefulness of the approach to the MMPH and body of the lateral meniscus (LM) was analyzed. Results: The average C-D percentage came out as 85.8, 101.3, 69.1% for each Group 1-A, B, C, and 102.4, 144.6, 116.8% for each Group 2-A, B, C. Measured E-length was an average of 15.1 (Group 1-A), 15.5 (Group 1-B, C), 13.1 (Group 2-A), and 12.9 mm (Group 2-B, C) and the change by valgus stress had no statistical significance. The F-length increased about 1.2 (Group 1) and 3.6 mm (Group 2) when valgus stress was applied, which had statistical significance (p<0.001, p<0.001). In Group 3, 49, 48 knees were classified as good for the MMPH, and the body of LM in aspect of the clinical usefulness of AM portal made on the PIP level. Conclusion: We identified the clinical usefulness of the PIP as a skin landmark of AM portal for the arthroscopic surgery of the MMPH.

• Food Science of Animal Resources
• /
• v.23 no.2
• /
• pp.128-136
• /
• 2003

This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.