천년을 사는 비법

박정만,Park, Jeong-Man 한국정보통신집흥협회 1999 정보화사회 Vol.131 No.-

여러 종류의 표면 진동원에 대한 연조직에서의 진동 변위 비교

박정만,권성재,정목근 한국비파괴검사학회 2012 한국비파괴검사학회지 Vol.32 No.5

The propagation characteristics of a mechanical wave in human soft tissue depend on its elastic properties. Investigation of these propagation characteristics is of paramount importance because it may enable us to diagnose cancer or tumor from the vibration response of the tissue. This paper investigates and compares displacement patterns generated in soft tissue due to several forms of low-frequency vibration sources placed on a surface. Among vibration sources considered are a normal load, tangential load, and antiplane shear load. We derive analytical expressions for displacements in viscoelastic single layers, and calculate displacement patterns in half space and infinite plate type tissue. Also, we simulate the vibration response of a finite-sized tissue using finite element method. The effects of the type of stress, the size and frequency of vibration sources, and medium boundaries on displacement patterns are discussed. 인체 연조직에서 기계적인 진동의 전달 특성은 조직의 탄성 특성에 의존한다. 연조직의 진동 특성으로부터 암이나 종양을 진단할 수 있기 때문에 진동의 전달 특성에 대한 연구는 중요한 의미를 가진다. 이 논문은 연조직의 표면에 위치하는 여러 형태의 응력 진동원에 의해 연조직 내에 발생되는 변위 패턴을 분석하고 비교하였다. 진동원으로는 수직하중, 접선하중, 그리고 면외전단하중이 고려되었다. 점탄성 단일층에서의 변위에 대한 이론적 표현식을 구하였고, 수치계산은 반공간 및 무한평판조직에서 수행되었다. 그리고 유한크기조직에서의 변위패턴을 유한요소법으로 시뮬레이션하였다. 응력 형태, 진동원 크기 및 주파수, 그리고 경계면이 변위에 미치는 영향이 분석되었다.

Pneumomediastinum after functional endoscopic sinus surgery under general anesthesia -A case report-

박정만,박영철,Jong Nam Lee,Jun Seok Ba,Shin Kyu Kang 대한마취통증의학회 2013 Korean Journal of Anesthesiology Vol.64 No.4

The occurrences of pneumothorax and pneumomediastinum are rare, but considered to be potentially life-threatening conditions in patients undergoing functional endoscopic sinus surgery under general anesthesia. Tracheobronchial rupture may results in serious complications, such as pneumothorax and pneumomediastinum. It may occur accidentally by endotracheal tube when the patient’s neck is flexed or extended. We report the case of a 48-year-old female patient who developed massive subcutaneous emphysema, pneumothorax, pneumomediastinum and pneumoperitoneum seven hours after functional endoscopic sinus surgery under general anesthesia.

Effect of Modularity on the Glauber Dynamics of the Dilute Spin Glass Model

박정만 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.9

We study the Glauber dynamics of the dilute, infinite-ranged spin glass model, the so-called diluteSherrington-Kirkpatrick (dSK) model. The dSK model has sparse couplings and can be classifiedby the modularity (M) of the coupling matrix. We investigate the effect of the modularity on therelaxation dynamics starting from a random initial state. By using the Glauber dynamics and thereplica method, we derive the relaxation dynamics equations for the magnetization (m) and theenergy per spin (r), in addition to the equation for the spin glass order parameter (q). In thereplica symmetric (RS) analysis, we find that there are two solutions for the RS spin glass orderparameter (q): q = 0 which is stable for r < 1/2 and q = (−1+4r2)/(32r4) which is stable for r > 1/2in the non-modular system and q = 0 which is stable for r < 1/p8 and q = (−1+8r2)/(128r4) whichis stable for r > 1/p8 in the completely modular system. By substituting the proper q values intothe equations for r, we find that the relaxation dynamics of r depends on the modularity, M. Theseresults suggest that, in the context of evolutionary theory, the modularity may emerge spontaneouslyin the point-mutation-only framework (Glauber dynamics) under a changing environment.

일상의 언쟁이 수행하는 생존-코미디 역학: 허스튼의 De Turkey and De Law

박정만 한국현대영미드라마학회 2007 현대영미드라마 Vol.20 No.1

Shear Wave Speed Imaging Using Unfocused Plane Wave Transmission

박정만,권성재,정목근 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.4

Purpose A shear wave is generated when a focused ultrasoundis transmitted to an imaging region of interest and themedium is pushed. The shear modulus can be quantitativelydetermined by measuring the speed of a shear wave in ahuman soft tissue. This paper presents a method of measuringthe speed of a quasi-planar shear wave propagating in theelevation direction in which a high-intensity burst-typeunfocused plane wave insonifies a wide area of soft tissuesimultaneously. Methods Experiments were carried out to acquire data fromelasticity phantoms subjected to burst-pulse plane waveinsonification, and the shear modulus was estimated bymeasuring the time to peak displacement as well as the timeto 80% of peak displacement. Results It was found that using the proposed method in aplastic ultrasound elasticity phantom, shear waves could begenerated up to a depth of 40 mm without focusing and thatshear wave speeds could be differentiated in both homogeneousand cylindrical inclusion phantoms. Conclusion The proposed method is advantageous in thatthe shear wave speed at all imaging points can be measuredsimultaneously and that an elasticity image can be constructedwith only a single pushing transmission. The shear wavespeed can be determined by measuring only the arrival timebased on the time-of-flight principle.

Mule Bone Kills De Turkey: Hurston and Hughes’s Artistic Contention on Black Folk Comedy

박정만 한국영어영문학회 2010 영어 영문학 Vol.56 No.6

Mule Bone (1931), Zora Neale Hurston’s collaboration with Langston Hughes, has been credited as the ‘first’ attempted by African Americans to create black folk comedy. The proposed research is driven from a question to the recent scholarship’s tacit consent on such historic importance imposed on the play. This paper suggests a possibility that De Turkey and De Law (1930), Hurston’s edition of the collaboration work,could be the truly first attempt in the tradition of American black folk comedy. By illuminating a series of historical moments in which Hurston first expressed her dream for writing a real black folk comedy that would be a really new departure in the African American drama, then collaborated with Hughes on the dream play project, and eventually quit the collaborationship due to artistic dispute with Hughes, this paper explains why Hughes edition Mule Bone came to remain ‘unfinished’ and, more importantly, fall short of Hurston’s original goal and expectation from the collaboration. On the other hand, this paper sheds light on the significance of often-ignored Hurston’s edition De Turkey and De Law by demonstrating how this play, compared to Mule Bone, fulfills her original idea of black folk comedy in terms of contents and themes compared with Mule Bone. Adding to the knowledge about little known behind story related to the Mule Bone controversy and the subsequent birth of the two different editions of the Hurston-Hushes collaboration project,supplementing the dearth of the related research with a critical comparison of the two editions, and discussing the validity of Hurston’s edition as the real sense of black folk comedy, this paper argues for the necessity of reconsidering the origin of the mentioned genre. This paper finally concludes that De Turkey and De Law, replacing Mule Bone, deserves a right to be truly the first American black folk comedy genre in the sense that it was completed and copyrighted three months earlier than Mule Bone and that, more importantly, it cherished the original aim and artistic vision of black folk comedy Hurston first planned and expected through the collaboration with Hughes.

저 가을 속으로

박정만 샘터사 1989 월간 샘터 Vol.20 No.11

誘電性 測定에 의한 琉璃纖維 强化 에폭시 樹脂 프리프레그의 硬化 觀察

朴正萬 建國大學校 附設 自然科學硏究所 1991 建國自然科學硏究誌 Vol.2 No.-

The use of dielectric measurements for monitoring the cure of fiber reinforced epoxy resin prepreg has been investigated. Measurements of dielectric constant and loss have been made at frequencies from 10 to 1000 KHz. The frequency dependence of the dielectric measurements has provided the basis for interpreting and understanding the signal in terms of dipolar and ionic phenomena. The results show that the dynamic dielectric analysis can be used to monitor and measure the viscosity, the state of the system, and the extent of the reaction as a function of time and temperature.

두꺼운 圓筒殼으로부터의 音波 共鳴散亂

朴正萬,金洪錫,신홍기 대진대학교 1995 大眞論叢 Vol.3 No.-

The resonance scattering of acoustic waves from thick cylindrical shells is analyzed for the case of an air-filled glass shell immersed in water. This is done by using the model of an elastic plate, and by calculating resonance frequencies, dispersion curves, and attenuations of circumferential waves. We also discuss some experimental results that deal with the backscattering of acoustic waves by cylindrical shells obtained by using short pulse excitation and Fourier spectroscopy analysis. Resonance spectra of backscattered signals show peaks corresponding to thickness resonances.