• Title, Summary, Keyword: FH

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Performance Analysis of FH/CPFSK System in the Partial-band Jamming Noise (부분대역 재밍하에서 FH/CPFSK 시스템의 성능 분석)

  • 정근열;박진수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.4
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    • pp.499-504
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    • 2002
  • In this paper, we analyzed the performance of FH/CPFSK system with differential detection in thermal noise, partial-band jamming noise and adjacent interference of all eight bit pattern. The parameters to analize performances of FH/CPFSK system have been used the bit rate, modulation index and performances of FH/CPFSK system with the differential detector have been presented with the optimum correlation function. And, we were compared with performance of FH/CPFSK and FH/BFSK system. In result, we could know that bit error probability of the approximation equation and exact equation nearly accorded in the high signal-to-noise ratio. And, we have been proved that FH/CPFSK system with differential detection according to jamming fraction ${\gamma}$ was worst to 3dB than FH/CPFSK system with limiter-discriminator. but was superior to 2dB than FH/BFSK.

Ab Initio Studies on the $(HF)_2(CO)$ Trimers ($(HF)_2(CO)$ 분자착물에 관한 Ab Initio 연구)

  • Kim, Seung Hoon
    • Journal of the Korean Chemical Society
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    • v.42 no.6
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    • pp.629-637
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    • 1998
  • The HF-SCF, MP2 and B3LYP calculations have been performed on the two conceivable clusters $(HF)_2(CO)$ trimers as well as their dimer complexes FH…FH, FH…CO and FH…OC applying $6-31+G^{\ast}^{\ast}$, and $6-311+G^{\ast}^{\ast}$ basis sets. A variety of ground state properties of these trimer complexes have been listed, and compared with corresponding properties of isolated monomers and combined dimers. It was calculated that FH…CO is more stable than FH…OC by average 0.85 kcal/mol and F-H…F-H…C≡O is more stable than F-H…F-H…O≡C by 1-2 kcal/mol. The C≡O stretching bands of the F-H…F-H…C≡O and F-H…F-H…O≡C were red shifted by 24, $37\;cm^{-1}$ compared with the FH…CO and FH…OC respectively. Also, H-F stretching bands were red shifted by 54 and $353\;cm^{-1}$.

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Maritime Wireless Data Communications of Predictive Frequency Hopping Technique

  • Bae, Sang-Hyun;Lee, Kwang-Ok;Jang, Bong-Seog
    • Journal of the Chosun Natural Science
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    • v.5 no.3
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    • pp.182-185
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    • 2012
  • In this paper, For 4th generation wireless communication systems, we propose a method to predict FH patterns in FH-OFDMA systems. OFDM is recognized as a promising modulation technique. Multi-user allocation in OFDM system can use FH that provides the spectrum-spread techniques. If one can generate more predictable FH sequences, then performance of the system can be easily improved. Current random FH and simple adaptive FH methods, however, are not considering predicting FH sequences. In this paper we show that the sampling of the wireless faded signal is not realized as a certain probability nature. With this regard, the proposed predictive FH allocation method is designed to embed the unknown probability models. Simulation study shows that the predictive FH method is more accurately predict FH sequences than the random or simple adaptive FH methods. We will further improve this proposed method to apply QoS control and MAC function development in OFDMA based wireless physical structures, especially maritime wireless data communications.

Screening, Diagnosis, and Treatment of Familial Hypercholesterolemia: Symposium of the Education Committee, Korean Society of Lipid and Atherosclerosis (가족성 고콜레스테롤혈증의 스크린, 진단, 치료: 한국지질동맥경화학회 교육위원회 심포지엄)

  • Lee, Chan Joo;Lee, Ji Hyun;Choi, Seonghoon;Kim, Shin-Hye;Kang, Hyun-Jae;Lee, Sang-Hak;Park, Kyong Soo
    • Journal of Lipid and Atherosclerosis
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    • v.7 no.2
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    • pp.122-154
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    • 2018
  • Familial hypercholesterolemia (FH) is typically associated with single gene mutation that is inherited by autosomal dominant manner. Due to high cardiovascular risk, aggressive discovery, diagnosis, and treatment of FH are critical. Although FH is being increasingly spotlighted, we do not have sufficient data on Korean patients with FH. Here, we present the content of symposium of the Education Committee, Korean Society of Lipid and Atherosclerosis held in May 2018: 1) epidemiology, clinical diagnosis, Korean FH data, and regulation in Korea; 2) genes associated with FH, sequencing process in suspicious proband, cascade screening, and difficulty in genetic diagnosis in FH; 3) the importance of lipid-lowering therapy in FH, conventional and novel therapeutics for FH; 4) diagnosis of FH in children and adolescence, screening, and treatment of FH in children and adolescence; 5) history of FH studies in Korea, the structure and current status of FH registry of Korean Society of Lipid and Atherosclerosis; and 6) difficulty in diagnosis of heterozygous and homozygous FH, drug intolerance and achievement of treatment target. Discussion between speakers and panels were also added. We hope that this article is helpful for understanding FH and future studies performed in Korea.

A ROENTGENOCEPHALOMETRIC STUDY ON THE SOFT TISSUE OF THE CHILDREN IN MIXED DENTITION (측모 두부방사선 계측법에 의한 혼합 치열기 아동의 연조직에 관한 연구)

  • Kim, Sun-Hae;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
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    • v.15 no.2
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    • pp.229-237
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    • 1985
  • The Purpose of this study was to investigate the differences in soft tissue characteristics according to the dental or skeletal dysplasia. For this purpose, lateral cephalogram of 153 children (Hellman dental age IIIB: control group 32, Angle CIII. div. 1 malocclusion group 55, Angle Cl III group 66) were traced and measured. For these measurements, following conclusions were made. 1. FH A, FH Sn, FH UL, AA' of the Class III group were thicker than those of the normal and Class II group, but FH B, FH LL, BB' of the Class III group were not significantly different from those of the normal group. 2. FH B, FH LL, BB' of the Class II group were thicker than those of the normal and Class III group, but FH A, FH Sn, FH UL, AA' of the Class II group were not significantly different from those of the noraml group. 3. Ans-Sn, FH P were not significantly different in three groups, while PP' of the Class III group was thicker than those of the other groups. 4. The lower lips of the Class II group were more anterioly everted with respect to the lower incisor inclination than those of the other groups. 5. The severity of skeletal dysplasia was partly camouflaged by the soft tissue.

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A comparative study between data obtained from conventional lateral cephalometry and reconstructed three-dimensional computed tomography images

  • Oh, Suseok;Kim, Ci-Young;Hong, Jongrak
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.40 no.3
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    • pp.123-129
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    • 2014
  • Objectives: The aim of this study was to verify the concordance of the measurement values when the same cephalometric analysis method was used for two-dimensional (2D) cephalometric radiography and three-dimensional computed tomography (3D CT), and to identify which 3D Frankfort horizontal (FH) plane was the most concordant with FH plane used for cephalometric radiography. Materials and Methods: Reference horizontal plane was FH plane. Palatal angle and occlusal plane angle was evaluated with FH plane. Gonial angle (GA), palatal angle, upper occlusal plane angle (UOPA), mandibular plane angle (MPA), U1 to occlusal plane angle, U1 to FH plane angle, SNA and SNB were obtained on 2D cephalmetries and reconstructed 3D CT. The values measured eight angles in 2D lateral cephalometry and reconstructed 3D CT were evaluated by intraclass correlation coefficiency (ICC). It also was evaluated to identify 3D FH plane with high degree of concordance to 2D one by studying which one in four FH planes shows the highest degree of concordance with 2D FH plane. Results: ICCs of MPA (0.752), UOPA (0.745), SNA (0.798) and SNB (0.869) were high. On the other hand, ICCs of gonial angle (0.583), palatal angle (0.287), U1 to occlusal plane (0.404), U1 to FH plane (0.617) were low respectively. Additionally GA and MPA acquired from 2D were bigger than those on 3D in all 20 patients included in this study. Concordance between one UOPA from 2D and four UOPAs from 3D CT were evaluated by ICC values. Results showed no significant difference among four FH planes defined on 3D CT. Conclusion: FH plane that can be set on 3D CT does not have difference in concordance from FH plane on lateral cephalometry. However, it is desirable to define FH plane on 3D CT with two orbitales and one porion considering the reproduction of orbitale itself.

Frequency Compatibility of FH Spread spectrum Communications in TV Channels (FH대역확산통신과 TV채널의 주파수 양립성에 관한 연구)

  • 박창일;조형래;이명수;강창언
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.1
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    • pp.84-92
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    • 1989
  • The purpose of this paper is to demonstrate the effect of a FH spread spectrum communication interference in TV channels and frequency compatibility in 30-88 MHz frequency band. To calculate this interferece, the strength of electric field of TV signals is derived as a function of distance between TV transmitter and receiver. An interference model is established based upon thefield strength by using the relation between the transmitted power of FH spread spectrum communications and the distance between the TV image signals, which makes TV screen a cceptble, Simultaneous transmission of FH sprea spectrum signals and TV signals is shown to be feasible, as far as the interference level is lower than the TV image signal level by 23.5dBm. As a result of frequency analysis and experiment, the FH spread spectrum communication can be used together with TV channels.

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Performance Analysis of FH MC/DS CDMA Stystem with Multi-tone Jamming over Nakakgami Fading Channel (나카가미 페이딩 채널하에서 멀티톤 재밍을 고려한 FH MC/DS CDMA 시스템의 성능분석)

  • Kim, Sang-Wook;Kim, Joon-Bae;Jung, Keun-Yeol;Yang, Jung-Mo;Park, Jin-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.543-546
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    • 2005
  • In this paper, it was estimated the BER performance of the individual system type by applying the SFH type and the FFH type to the FH MC-DS CDMA system that combined the strong points of MC DS/CDMA and that of Frequency Hopping under the Nakagami fading channel with Multi-tone Jamming. An increase in the number of hoppings means that it can improve the BER performance by reducing the receiving burden of the FH MC DS/CDMA by achieving a frequency diversity effect. Therefore, I verified that the performances of the FH MC DS/CDMA system could be improved by increasing the number of hoppings.

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Performance Analysis of FH MC/DS CDMA Stystem with Multi-tone Jamming over Nakakgami Fading Channel (나카가미 페이딩 채널하에서 멀티톤 재밍을 고려한 FH MC/DS CDMA 시스템의 성능분석)

  • Kim Sang-Wook;Park Jin-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.4
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    • pp.693-697
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    • 2005
  • In this paper, it was estimated the BER performance of the individual system type by applying the SFH type and the FFH type to the FH MC-DS CDMA system that combined the strong points of MC DS/CDMA and that of Frequency Mewing under the Nakagami fading channel with Multi-tone Jamming. An increase in the number of hoppings means that it can improve theBER performance by reducing the receiving burden of the FH MC DS/CDMA by achieving a frequency diversity effect. Therefore, I verified that the performances of the FH MC DS/CBMA system could be impoved by increasing the number of hoppings.

Design of MJPEG Encoder for FH/TDD Multiple Transmissions (FH/TDD 다중전송용 MJPEG 부호화기 설계)

  • Kang, Min-Goo;Sonh, Seung-Il
    • Journal of Internet Computing and Services
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    • v.12 no.4
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    • pp.45-50
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    • 2011
  • In this paper, the encoding time delay of FH/TDD(Frequency Hopping/Time Division Duplex) based Motion JPEG image compression CODEC is analyzed for radio video transmissions of multi-camera systems in a vehicle. And, Synchronized connection of minimum channel collision is designed with synchronized shift and access according to channel status for Motion JPEG based FH/TDD multiple access.