Air puff에 의한 각막 변형의 주파수 영역 분석

황호식,이병하,이창수,Hwang, Ho-Sik,Lee, Byeong Ha,Lee, Chang Su 한국전기전자학회 2014 전기전자학회논문지 Vol.18 No.2

안압의 측정은 각막에 air puff 후 각막의 변형 즉, 각막의 두께나 변위 등 생역학적 성질을 관찰함으로써 이루어진다. 본 논문에서는 녹내장이나 라식의 진단을 위하여 사용되는 안압계의 air puff에 의한 각막의 변형을 주파수 영역에서 분석하였다. Air puff 후 각막의 중심부 주변의 변위에 대한 진동 주파수를 측정함으로써 환자와 정상인을 구별한다. 동영상으로부터 이진 영상을 구하고, 상하 변위 데이터와 곡선 정합의 차를 구하여 시간에 따른 각막 상하 진동 프로파일 데이터를 추출하였다. Fourier 변환으로 비정상인의 진동 주파수는 479.2Hz를 얻었고 정상인의 경우 단단함으로 인하여 702.8Hz의 고주파 성분을 볼 수 있었다. 또한 Hilbert-Huang 변환의 EMD 방법을 이용, 고유 모드 함수로 분해하여 국소적, 비선형, 비정상성을 가지는 데이터를 얻고 주파수와 전력을 분석하였다. 마지막으로 특정 고유 모드 함수에 대한 환자와 정상인의 전력비가 6배 이상 차이가 나는 것을 확인하였다. Intraocular pressure is measured after a cornea air puff by observing biomechanical properties such as thickness or displacement of the cornea. In this paper, we deal with a frequency domain analysis of corneal deformation in the air puff tonometry that is used to diagnose glaucoma or lasik. We distinguish the patient from the normal by measuring the oscillation frequency in the neighborhood of the central cornea section. A binary image was obtained from the video images, and cornea vertical oscillation profile was extracted from the difference between the vertical displacement data and the curve fitting. In terms of Fourier transform, a vibration frequency of 479.2Hz for the patient was obtained as well as more higher 702.8Hz for the normal due to stiffness. Hilbert-Huang transform's empirical mode decomposition generally describes local, nonlinear, and nonstationary data. After the data were decomposed into intrinsic mode functions, a spectrum and power were analysed. Finally, we confirm that the patient has 6 times more higher power ratio for the specific intrinsic mode function between the patient and the normal.

양안 각막이식에서 먼저 수술한 눈과 나중에 수술한 눈의 이식거부반응의 비교

황호식,김수영,김만수.Ho Sik Hwang. M.D.. Su Young Kim. M.D.. Man Soo Kim. M.D. 대한안과학회 2007 대한안과학회지 Vol.48 No.9

Purpose: To compare graft rejection of the first and second eyes after bilateral penetrating keratoplasty. Methods: We performed a retrospective review of the cases of 16 patients who underwent bilateral penetrating keratoplasty. Nonparametric Kaplan-Meier survival analysis was used to account for variable follow-up among patients. Results: The mean age of the 16 patients (12 M, 4 F) was 39.1 years. Mean follow-up was 89.8 months after surgery in the first eye and 42.8 months after surgery in the second eye. The average time interval between surgery on the first and second eyes was 47.0 months. The indications for surgery were keratoconus (37.5%), corneal dystrophy (25.0%), pseudophakic bullous keratopathy (12.5%), band keratopathy (12.5%), and inflammatory corneal opacity (12.5%). Endothelial rejection occurred in five of the first eyes but was treated successfully, remaining clear until the last follow-up. Endothelial rejections were seen in five of the second eyes, two of which failed. Survival analysis of endothelial rejection showed no significant difference between the first and second eyes; however, survival analysis of the graft failure showed a decreased survival rate of the second eyes compared with that of the first eyes. The best corrected visual acuity at the last follow-up of the second eyes seemed to be worse than that of the first eyes. Conclusions: Survival analysis of the endothelial rejections showed no significant difference between the first and second eyes. Survival analysis of the graft failure showed decreased survival rate of the second eyes. At the last follow-up the best corrected visual acuity of the second eyes appeared to be worse than that of the first eyes.

Double-Pass System (Optical Quality Analysis System) for Analysis of the Multifocal Function of a Diffractive Multifocal Intraocular Lens (Acrysof ReSTOR®) Compared to a Monofocal Intraocular Lens (Acrysof IQ®)

황호식,신혜영,주천기 한국광학회 2014 Current Optics and Photonics Vol.18 No.2

In this study, we objectively determined whether the ReSTOR as a multifocal IOL (intraocular lens) has a multifocal function compared to the IQ as a monofocal IOL in vivo by OQAS (Optical Quality Analysis System). Eighteen patients who had cataract surgery with implantation of ReSTOR (27 eyes) and 15 patients with IQ (21 eyes), were included inthis study. Uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UCNVA)and distance corrected near visual acuity (DCNVA) were measured. After setting the artificial pupil size to 3 mm, we performed ‘Optical quality’. We inputted defocusdiopters of (objective spherical refraction)(far), (objective spherical refraction-1.25 D)(intermediate),(objective spherical refraction-2.5 D)(near), and (objective spherical refraction-3.5 D)(very near) into ‘selected spherical refraction’ simulating theoptical quality at far, intermediate, and near distance. We changed the pupil size to 5 mm and repeated thesame measurements. The UCDVA and CDVA did not show significant differences between the 2 groups. But, theUCNVA and DCNVA of the ReSTOR group were better than those of the IQ group (p=0.000, p=0.000). For 3 mm pupil, at far distance, modulation transfer function (MTF) cut off and point spread function (PSF) width at 50% of ReSTOR were worse than those of IQ (p=0.039, p=0.020). At intermediate distance, MTF cut off, Strehl ratio and PSF width at 50% of ReSTOR were worse than those of IQ (p=0.001, p=0.001, p=0.000). At near distance, MTF cut off of ReSTOR was worse than that of IQ (p=0.033). At very near distance, MTF cut off and Strehl ratio of ReSTOR were worse than those of IQ (p=0.002, p=0.002), but PSF width at 50% of ReSTOR was better than that of IQ. For 5 mm pupil, most parameters at each distance, there was no significant difference between the 2 groups. Only PSF width at 50% of ReSTOR were worse than those of IQ at intermediate distance (p=0.013). It was impossible to show the multifocal function of ReSTOR compared to the IQ byOQAS.

전신성 홍반성 루푸스에서 발생한 심한 결막부종을 동반한 일과성 근시

황호식,김도현,Ho Sik Hwang,Do Hyun Kim 대한안과학회 2007 대한안과학회지 Vol.48 No.10

Purpose: To report a transient myopia with severe chemosis associated with systemic lupus erythematosus. Methods: A 31-year-old woman was referred for decreased visual acuity of both eyes for 1 week. The patient came to the emergency medical center for facial edema and fever. She was examined and treated for systemic lupus erythematosus. Three years previously the patient underwent LASIK in both eyes, and maintained emmetropia postoperatively. Results: At admission, spherical equivalent was -0.75D in the right eye and -6.5D in the left eye. On the 3rd day, the spherical equivalent was -11.0D in the right eye and -10.0D in the left eye and progressively decreased to -2.0D both eyes by the 12th hospital day. The mean corneal power was 39.8D in the right eye and 39.9D in the left eye on the 2nd hospital day and decreased to 38.8D in the right eye and 38.9D in the left eye by the 12th hospital day. The axial length change was not parallel with myopic changes. The anterior chamber depth was 2.14 mm in the right eye and 1.94 mm in the left eye on the 3rd hospital day and increased to 2.96 mm in the right eye and 2.84 mm in the left eye by the 12th hospital day. Under cycloplegic refraction, ciliary spasm was not evident. The bulbar conjunctivas were markedly chemotic on the 3rd hospital day, but after systemic steroid therapy the chemosis subsided and the conjunctivas became normal by the 12th hospital day. The patient was diagnosed with systemic lupus erythematosus and after medical treatment, was discharged from the hospital. J Korean Ophthalmol Soc 48(10):1445-1448, 2007

욕망 조절을 위한 순자의 사회규범론

황호식 고려대학교 중국학연구소 2010 中國學論叢 Vol.29 No.-

This essay attempts to investigate the relationship between human desires and social norms in Xunzi. It can be stated that Xunzi is one of the first philosophers to take human desires as his major issue and to build his theory in Chinese philosophy. Therefore, to explore Xunzi`s philosophy of human desires is significant since we can have a sense of Eastern philosophies of human desires, especially, in Korean academic circles where Western theories of human desires are mainly on the table. According to my study, Xunzi defines human beings as born with desires and social at the same time. Furthermore, he examines how human beings can achieve peace in a society. As a result, he suggests Confucian ritual norms as a social regulation to nurture human desires and to control human tendency to pursue their desires to the extreme, which can bring strife and disorder to the society. Only when human beings guide their desires in the right way of Confucian ritual norms are they able to lead harmonious lives with each other in the society.

순자의 인성론에 담긴 사회철학적 의미

황호식 범한철학회 2010 汎韓哲學 Vol.57 No.2

There have been great studies on Xunzi's theory of human nature. Still, scholars propose different interpretations of the theory without general agreements among themselves. In my opinion, it is partly because they just tend to focus on the argument of “xing e (性惡).” They have been trying to understand Xunzi's philosophy with the premise that “xing e” is the foundation on which his other arguments are based. It leads them to find difficult in a logical link between Xunzi's theories of bad human nature and moral rules. Therefore, Xunzi's theory of human nature has been degraded as self-contradictory or even the chapter “Xing E (性惡)” has been considered as inauthentic. However, Xunzi's theory of human nature possesses two folds of connotations: “xing e” and “weishan (僞善).” In my opinion, we can grasp better what Xunzi tried to convey through his theory of human nature only when considering both the first connotation and the second one, which has been ignored. Accordingly, this essay intends to disclose the true meaning of Xunzi’s theory of human nature by examining its two folds of connotations, as pointed out earlier. In order to achieve my purpose, I shall apply a social philosophical approach to Xunzi's theory of human nature. First of all, with regard to Xunzi's argument of “xing e”, I shall discuss why Xunzi considers human's boundless desires as bad in a social context on the basis of his view of humans as social beings. Second, concerning another argument of “weishan”, I shall examine how social rules are established in order to regulate the infinite human desires, and Xunzi's belief that only Confucian rituals and righteousness (禮義) can transform bad human nature to good one. I think that this social philosophical method will shed a new light on Xunzi's theory of human nature, different from the traditional metaphysical analysis of it. 지금까지 순자의 인성론에 대해서는 아주 잘 탐구되어 왔다. 그럼에도 순자의 인성론에 담긴 의미를 둘러싸고 다양한 해석이 표출되고 있다. 그 배경에는 ‘사람의 본성이 악하다’(人之性惡)는 주장에만 초점을 맞춰온 연구경향도 한몫을 하는 듯하다. ‘성악’(性惡) 개념에 토대를 두고 연역해나가는 방식으로 순자의 철학체계를 이해하려다 보니, 악한 본성과 도덕규범 사이의 관계를 정합적으로 설명해내기가 어렵다. 그래서 순자의 인성론은 모순을 지닌 주장으로 폄하되거나, 심지어 「성악」편이 위작(僞作)이라는 주장까지도 제기되어 왔다. 그러나 순자의 인성론에는 ‘사람의 본성이 악하다’는 주장만이 아니라 ‘악한 본성을 선하게 변화시키는 것은 인위이다’(其善者僞也)는 주장도 담겨있다. 필자는 그 동안 곧잘 간과되어온 후자의 주장을 함께 고려할 때 순자가 자신의 인성론을 통해 말하려 했던 진의가 올바로 이해될 수 있다고 생각한다. 따라서 이 글에서는 ‘성악’에 담긴 의미만이 아니라 ‘위선’(僞善)에 실린 의미도 함께 밝혀나감으로써 순자의 인성론이 지닌 의미를 온전히 드러내고자 한다. 이를 위해 필자는 순자의 인성론에 대하여 사회철학적 접근을 시도한다. 먼저 ‘성악’에 담긴 의미를 분석할 때는 사람을 사회적 존재로 파악하는 순자의 인간관에 기초하여 욕망의 무제한성이 사회적 맥락에서 악으로 규정되는 과정을 살핀다. 이어서 ‘위선’에 실린 의미를 분석할 때는 욕망의 무제한성에서 비롯하는 사회규범의 대두 과정과 여러 사회규범 중에서 오직 유가적 예의만이 악한 본성을 선하게 변화시킬 수 있다는 순자의 이념적 확신을 짚어본다. 이렇게 사회철학적 접근에 의해 밝혀질 순자의 인성론에 담긴 의미는 기존에 형이상학적 접근을 통해 밝혀온 것과는 색다른 면모를 보여줄 것이다.

고사부리성의 변천과정 연구

황호식 전북연구원 전북학연구센터 2022 전북학연구 Vol.6 No.-

편집자에게 보내는 글

황호식,정태영 대한안과학회 2017 대한안과학회지 Vol.58 No.4

맹자의 윤리적 감정관과 그 인지주의적 성격

황호식(Hwang Ho sik) 한국동양철학회 2014 동양철학 Vol.0 No.42

중국의 전국시대 유학자였던 맹자는 윤리적 행위와 관련하여 감정, 특히 네 가지 도덕 감정으로서 '사단'(四端)이 수행하는 역할과 그 의미에 대하여 체계적인 사유를 전개하였다. 맹자가 윤리적 행위의 동기와 근거로서 감정을 이해하는 관점은 합리적 행위 여부와 관련하여 감정에 내포된 인지적 요소를 주목하는 인지주의(cognitivism) 입장과 닮은 것으로 보인다. 이 글에서는 맹자의 감정에 관한 입론이 인지주의 감정 이론과 상통하는 면모를 지니고 있다는 점에 착안하여 맹자의 윤리적 감정관에 대한 인지주의적 접근을 시도하고자 한다. 먼저 인지주의적 접근을 위한 출발점으로서 과연 현대의 감정 연구자들이 전형적으로 설정해온 '감정'(emotion) 범주가 맹자의 철학에서 찾아질 수 있는지를 탐색한다. 이어서 맹자의 사유에서 드러나는 감정 범주가 어떤 점에서 인지주의 감정 이론과 유사성을 지니고 있는지를 분석한 다음, 맹자가 윤리적 행위의 원천적 기반으로 제시하는 '사단' 가운데 '측은지심'(惻隱之心)[또는 '불인인지심'(不忍人之心)]에 초점을 맞춰 그에 내포된 인지적 요소를 규명해본다. 결과적으로 이러한 시도는 맹자의 윤리적 감정관과 인지주의 감정 이론 사이에서 발견되는 흥미로운 유사성을 밝혀줄 수 있을 것이며, 나아가 도덕 감정으로서 '측은지심'이 지닌 합리적 성격을 재확인할 기회를 제공할 수 있을 것으로 기대한다. Mencius, one of Chinese philosophers during the Warring States period, had thought systematically on the role and meaning that the emotion concerned with ethical behavior, i.e. the four moral sentiments, so to speak, the four sprouts(四端) can play and suggest. It seems to me that Mencius' argument about regarding the emotion as the motive and ground of ethical behavior has resemblance with cognitivism which focuses on the cognitive elements of emotion that enables us to act rationally. I think that Mencius' viewpoint of emotion can be close to the cognitive theory of emotion. So in this paper, I try to approach Mencius' ethical position of emotion from a perspective of cognitivism. Before we start to analyze Mencius' ideas of emotion, we should examine first whether Mencius established the category of 'emotion' that contemporary specialists of emotion have paid attention to. Second, I will show that the category of emotion in Mencius' ideas can be similar with the cognitive theory of emotion in some respects. Third, I want to analyse the compassion(惻隱之心) or 'the feeling of not being able to endure other people's suffering harm'(不忍人之心) among the four sprouts that Mencius proposes as the basic foundation of ethical action and to point out the cognitive elements in it. After all, I hope that we can disclose an interesting similarity between Mencius' ethical position of emotion and cognitive theory of emotion by means of this course.

Train of four와 1Hz 자극에 의한 Pancuronium의 근육이완 평가

黃鎬植 中央醫學社 1983 中央醫學 Vol.45 No.6

There are many reports that pancuronium has various muscle blocking effect in man and animal. Despite an attempt to diminish the variation in responses to relaxants by standardizing experimental techniques such as anesthetic concentration kept constant, acid base status kept constant, pre medication omitted, and dosage calculated in terms of mg/kg, the marked variation was found to persist, and also stimuli frequency dependant response was suggested. Therefore experimental study was performed by different stimulus frequency was applied to evaluate the neuromuscular blocking effect of pancuronium. The experiment was performed on fourteen rabbits weighing 1.8 to 2.2 kg and these were divided into two groups; eight rabbits for 1 Hz group and six rabbits for Train of four group. All animals were intubated through tracheostomy under general anesthesia with intraperitoneal urethane. Respiration was controlled by means of a Harvard animal respirator. The body temperature was kept at 35°C with a thermo-blanket. The common peroneal nerve and anterior tibial muscle was exposed and the nerve stimulator was applied to the nerve muscle preparation. The twitch height of the muscle contraction was recorded on a biophysiograph through the force displacement transducer. The common peroneal nerve was stimul-ated supramaximally by 1 Hz and Train of four. The degree of neuromuscular block following intravenous injection of pancuronium 0.03 mg/kg was measured in each group. The changes of the twitch height and the time of spontaneous recovery was compared in each group. The results were as follows; I. In 1 Hz group; full recovery of twitch height was observed in only half of the number of experimental animals(50%). Another half of the animals shown, maximal twitch height recovery was 66.6%, 68%, 70%, and 72%. Mean-while T, of Train of four response was shown 100% recovery. 2. In Train of four group; all animals shown 100% recovery of T4 and recovery index was 334.2 sec. 3. It is confirmed that Train of four method is more precise method than 1 Hz to evaluate the non-depolarizing muscle relaxants.