워터마킹 영상의 비가시성 개선에 관한 연구

고석만,김형균,오무송 조선대학교 전자정보통신연구소 2002 電子情報通信硏究所論文誌 Vol.5 No.2

The use of digital imaging technique and digital contents based on internet has grown rapidly for last several years, and the needs of digital image protection become more important. For the purpose of copyright protection on digital image, the verification of authentication techniques like content authentication, ownership authentication, illegal copy and etc are needed. Digital watermarking, the invisible encryption technique to insert digital watermark into image, the sophisticated perceptual information should be used for providing transparency and robustness of images on watermarking process. In this paper, we implement the algorithm for preventing forged attack, ownership protection and authentication by transforming the wavelet algorithms in frequency domain in terms of human visual system.

애니메이션의 효율적인 동작 제어에 관한 연구

김형균,고석만,오무송 조선대학교 전자정보통신연구소 2003 電子情報通信硏究所論文誌 Vol.6 No.1

본 논문에서는 캐릭터 애니메이션의 효율적인 동작 제어를 위하여 익스프레션을 이용한 애니메이션을 제작하였다. 익스프레션을 이용한 애니메이션은 움직임의 표현에 있어서, 자연스러운 애니메이션을 좀더 쉽고 유용하게 표현하기 위한 방법으로 캐릭터의 동작 제어점들을 분석하여 익스프레션에서 애니메이션을 제어할 수 있는 요소를 찾아 그 식에 사용하였으며, 이것을 토대로 캐릭터의 동작을 자동적으로 제어하는 애니메이션을 구현하였다. 익스프레션에 의한 애니메이션은 간편한 조작으로 자연스럽고 현실적인 움직임을 생성할 수 있다는 익스프레션의 효율성이 장점으로 나타났지만, 애니메이터에 의한 키 프레임 방식에 의한 애니메이션보다는 어색함을 보였다. This paper manufactured animation to use expression for efficient action control of character animation. Animation to use expression is method to express natural animation little more easily and usefully in expression of motion Find urea that could control animation in expression analyzing action control points of character and used in ceremony Embodied animation to control automatically action of character on the basis of this. Efficiency of expression that animation by expression can create natural and realistic action by manufacturing that is simple was expose by advantage, but showed awkwardness than animation by key frame way by animator.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

Differences in Physical Examination Outcomes between Sacroiliac Joint Motion Restricted and Painful Groups in Patients with Lumbopelvic Pain

Hyeong-Seok Oh(Hyeong-Seok Oh),Duk-Hyun An(Duk-Hyun An),Won-Gyu Yoo(Won-Gyu Yoo) 한국임상움직임치료학회 2022 한국임상움직임치료학회지 Vol.2 No.2

Background Among sacroiliac joint (SIJ) special tests, motion palpation tests (MPT) are commonly used to assess possible SIJ motion dysfunction. Pain provocation tests (PPT) attempt to assess whether or not the stressed structure is a source of pain. Pain and dysfunction are dissimilar concepts and should be differentiated from each other in clinical practice. Objectives The purpose of this study was to compare differences in physical examination outcomes (hamstring muscle length, isometric gluteus maximus strength, pelvic rotation angle during active straight leg raise (ASLR) and visual analog scale (VAS) between motion-restricted and painful groups of patients with low back pain (LBP). Methods Thirty-two patients between the ages of 18 and 45 participated. Four MPT (Gillet, standing flexion, sitting flexion, and supine to sit) and five PPTs (compression, distraction, Gaenslen's, thigh-thrust, and sacral-thrust) were used for distinguishing subjects with SIJ dysfunction. Independent t-test analysis was used to compare physical examination outcomes between the two groups. Results Results showed that SIJ PPT groups were significant changes (p = 0.028) in hamstring length compared to the SIJ MPT groups, and the subjective pain level (VAS) also showed a significant result. (p < 0.001) In the measurement of the pelvic rotation angle during the ASLR, the MPT group showed a more significant change in pelvic rotation angle than the PPT group (p = 0.043) However, our data did not show a significant difference in the isometric gluteus maximus strength of the two groups. (p = 0.882) Conclusions Based on these results, therapeutic interventions for SIJ dysfunction should be appropriately and harmonized by identifying the differences and unique features of the two test methods, and new evaluation methods combining these two methods are required.

Anterior Dislodgement of a Fusion Cage after Transforaminal Lumbar Interbody Fusion for the Treatment of Isthmic Spondylolisthesis

Oh, Hyeong Seok,Lee, Sang-Ho,Hong, Soon-Woo The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.54 No.2

Transforaminal lumbar interbody fusion (TLIF) is commonly used procedure for spinal fusion. However, there are no reports describing anterior cage dislodgement after surgery. This report is a rare case of anterior dislodgement of fusion cage after TLIF for the treatment of isthmic spondylolisthesis with lumbosacral transitional vertebra (LSTV). A 51-year-old man underwent TLIF at L4-5 with posterior instrumentation for the treatment of grade 1 isthmic spondylolisthesis with LSTV. At 7 weeks postoperatively, imaging studies demonstrated that banana-shaped cage migrated anteriorly and anterolisthesis recurred at the index level with pseudoarthrosis. The cage was removed and exchanged by new cage through anterior approach, and screws were replaced with larger size ones and cement augmentation was added. At postoperative 2 days of revision surgery, computed tomography (CT) showed fracture on lateral pedicle and body wall of L5 vertebra. He underwent surgery again for paraspinal decompression at L4-5 and extension of instrumentation to S1 vertebra. His back and leg pains improved significantly after final revision surgery and symptom relief was maintained during follow-up period. At 6 months follow-up, CT images showed solid fusion at L4-5 level. Careful cage selection for TLIF must be done for treatment of spondylolisthesis accompanied with deformed LSTV, especially when reduction will be attempted. Banana-shaped cage should be positioned anteriorly, but anterior dislodgement of cage and reduction failure may occur in case of a highly unstable spine. Revision surgery for the treatment of an anteriorly dislodged cage may be effectively performed using an anterior approach.

Clinical and Radiological Comparison of Femur and Fibular Allografts for the Treatment of Cervical Degenerative Disc Diseases

Oh, Hyeong-Seok,Shim, Chan Shik,Kim, Jin-Sung,Lee, Sang-Ho The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.53 No.1

Objective : This consecutive retrospective study was designed to analyze and to compare the efficacy and outcomes of anterior cervical discectomy and fusion (ACDF) using a fibular and femur allograft with anterior cervical plating. Methods : A total of 88 consecutive patients suffering from cervical degenerative disc disease (DDD) who were treated with ACDF from September 2007 to August 2010 were enrolled in this study. Thirty-seven patients (58 segments) underwent anterior interbody fusion with a femur allograft, and 51 patients (64 segments) were treated with a fibular allograft. The mean follow-up period was 16.0 (range, 12-25) months in the femur group and 19.5 (range, 14-39) months in the fibular group. Cage fracture and breakage, subsidence rate, fusion rate, segmental angle and height and disc height were assessed by using radiography. Clinical outcomes were assessed using a visual analog scale and neck disability index. Results : At 12 months postoperatively, cage fracture and breakage had occurred in 3.4% (2/58) and 7.4% (4/58) of the patients in the femur group, respectively, and 21.9% (14/64) and 31.3% (20/64) of the patients in the fibular group, respectively (p<0.05). Subsidence was noted in 43.1% (25/58) of the femur group and in 50.5% (32/64) of the fibular group. No difference in improvements in the clinical outcome between the two groups was observed. Conclusion : The femur allograft showed good results in subsidence and radiologic parameters, and sustained the original cage shape more effectively than the fibular allograft. The present study suggests that the femur allograft may be a good choice as a fusion substitute for the treatment of cervical DDD.

Parasitic Capacitance Analysis of PCB-type Induction Heating Coil and LCCC/S Matching Network Design for Railway Turnouts

Oh Hyeong-Seok,Lee Jaehong,Lee Seung-Hwan,Park Chan-Bae,Lee Jae-Bum,Lee Ju,Lee Hyung-Woo 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4

Conventional de-icing systems use resistive heating wires to prevent the freezing of railway turnouts. Because of the low efficiency of the heating wires, induction heating (IH) systems have been investigated recently. The IH systems utilize high-frequency resonant inverters and heating coils to induce eddy currents and heat energy on heating plates. The heating coils can be manufactured with a printed-circuit-board (PCB) process. However, a short distance between PCB patterns can generate a significant parasitic capacitance, which resonates with the coil inductance. A self-resonance of the coil makes capacitive impedance at high-frequency ranges and distorts coil currents. This paper investigates the parasitic capacitance of PCB-type induction heating coils. Analytic models of the PCB-type heating coil are derived. In addition, a new LCCC/S impedance matching network (IMN) design that compensates for the parasitic capacitance is presented. The developed induction heating coil and IMN are demonstrated using experimental results.

철도 분기부 융설용 대면적 발열을 위한 전도판 설계 및 분석

오형석(Hyeong-Seok Oh),박찬배(Chan-Bae Park),이재범(Jae-Bum Lee),이주(Ju Lee),조익현(Ik-Hyun Jo),이형우(Hyung-Woo Lee) 한국철도학회 2021 한국철도학회논문집 Vol.24 No.11

달빅 가상 머신에서의 장기 추적 방식 적시 컴파일

오형석(Hyeong-Seok Oh),문수묵(Soo-Mook Moon) 한국정보과학회 2011 정보과학회논문지 : 시스템 및 이론 Vol.38 No.3

구글의 모바일 플랫폼인 안드로이드에서는 기존의 자바 어플리케이션을 수행하기 위해 자바 클래스 파일을 덱스(dex) 파일로 변경한 뒤 달빅 가상 머신을 통해 수행한다. 달빅은 레지스터 기반의 가상머신으로 인터프리터 외에 추적(trace) 기반의 경로 컴파일 정책을 사용하여 달빅 바이트코드를 머신 코드로 번역하여 수행하는 적시 컴파일러를 탑재하였다. 본 논문에서는 달빅 가상 머신의 적시 컴파일러에서 사용하는 추적 단위를 확장하는 장기 추적 방식으로 변경하는 것을 제안한다. 이를 통해 더 많은 바이트코드 명령어를 함께 컴파일하여 컴파일 시간은 길어져도 더 좋은 머신 코드를 생성할 수 있어 하이브리드 컴파일 환경 등을 구축하는 데 유용하다. 실험을 통해 달빅 가상 머신의 성능 향상 가능성을 확인하였다. Google’s mobile platform, Android, executes Java applications by converting Java class files into Dex files and executing them on Dalvik virtual machine. Dalvik is a register-based virtual machine and it includes an interpreter and a just-in-time compiler (JITC) which employs trace-based path compilation for translating Dalvik bytecode to machine code. This paper proposes extending the trace unit for Dalvik JITC so that we can have longer traces. This allows compiling more Dalvik bytecode instructions together to generate better machine code with slightly longer compilation time, which can allow building a hybrid compilation environment. Our experimental results show the possibility of performance improvement for Dalvik virtual machine.

달빅 가상 머신에서의 장기 추적 방식 적시 컴파일

오형석(Hyeong-Seok Oh),문수묵(Soo-Mook Moon) 한국정보과학회 2010 한국정보과학회 학술발표논문집 Vol.37 No.2A