로드헤더 장비사양 검토 및 굴착효율 예측 모델 개발

정재훈,임주휘,이재원,강한별,김도훈,신영진,Jae Hoon Jung,Ju Hyi Yim,Jae Won Lee,Han Byul Kang,Do Hoon Kim,Young Jin Shin 한국터널지하공간학회 2023 한국터널지하공간학회논문집 Vol.25 No.3

The use of roadheaders has been increasing to mitigate the problems of noise and vibration during tunneling operations in urban area. Since lack of experience of roadheader for hard rock, the selection of appropriate machines and the evaluation of cutting rates have been challenging. Currently, empirical models developed overseas are commonly used to evaluate cutting rates, but their effectiveness has not been verified for domestic rocks. In this paper, a comprehensive literature review was conducted to assess the rock cutting force, cutterhead capacity, and cutting rate to select the appropriate machine and evaluate its performance. The cutterhead capacity was reviewed based on the literature results for the site. Furthermore, a new empirical model and simplified method for predicting cutting rates were proposed through data analysis in relation to operation time and rock strength, and compared with those of the conventional model from the manufacturer. The results show good agreement for high strength range upper 80 MPa of uniaxial compressive strength.

Arrayed Waveguide Grating의 스펙트럼해석

정재훈,Jung, Jae-Hoon 한국전기전자학회 2004 전기전자학회논문지 Vol.8 No.1

Arrayed waveguide grating의 스펙트럼을 해석하기 위해 Fresnel Kirchhoff diffraction 식과 Fraunhofer diffraction 근사식을 이용하여 실제로 제작되는 16채널 및 40채널의 arrayed waveguide grating에 대해 적용해 보았으며 Fraunhofer diffraction 근사식을 적용할 때 생기는 문제점을 모델별로 도출하였고 그 오차를 실제의 공정오차와 비교하였다. We performed the spectrum analysis of arrayed waveguide grating using Fresnel Kirchhoff diffraction formula and its approximated Fraunhofer diffraction equation and applied both methods to 16 channel and 40 channel models. We presented the spectra and found out the limitations of Fraunhofer diffraction in analysis of arrayed waveguide grating and compared the errors coming from Fraunhofer diffraction approximation and due to imperfection during the fabrication process.

수종(數種)의 한약재의 Tyrosinase와 Elastase 활성 억제 효과에 대한 실험적 연구

정재훈,김경준,Jung, Jae-Hoon,Kim, Kyung-Jun 대한한방안이비인후피부과학회 2009 한방안이비인후피부과학회지 Vol.22 No.2

Objectives : The purpose of this study is to investigate whitening effects and anti-wrinkle effects of a few 80% ethanol extracted herbal medicines. Methods : In the first study, a few 80% ethanol extracted herbal medicines were screened for their inhibitory activities against the tyrosinase. In the second study, a few 80% ethanol extracted herbal medicines were screened for their inhibitory activities against elastase. Results : 1. We showed 28%, 27% and 19% inhibitions of mushroom tyrosinase at 500 $\mu$g/ml concentration of ASR, AIF and ABR extracts and they were showed higher anti-tyrosinase activity than arbutin's. We also could observe that the decreased mushroom tyrosinase activities in RR, CML, LR, AGR and TH extracts. 2. RR, AF and ABR (final concentrstion 1 mg/ml) were appeared 60%, 98%, 83% of inhibitions of elastase activity, and they were showed higher anti-elastase activity than that of ursolic acid. We also could observe that the decreased elastase activities in AIF, AR, LR and CML extracts. Conclusions : These results suggest that ASR, AIF and ABR extracts contribute to the anti-melanin activities and represent potential sources of whitening agent, and RR, AF and ABR extracts contribute to the anti-elastase activities and represent potential sources of anti-wrinkle agent. These results suggest that some herbal medicines could be strong potential sources of inhibition about anti-aging and whitening effects for the skin.

단일 광섬유 브래그 격자와 EDFA를 이용한 온도와 스트레인의 동시 측정

정재훈,남희,이병호,Jung, Jae-Hoon,Nam, Hui,Lee, Byoung-Ho 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.6

We propose and demonstrate a novel sensor which can simultaneously measure strain and temperature. The sensor is composed of a single fiber Bragg grating and an erbium-doped fiber amplifier. Using linear variation in the amplified spontaneous emission power of an erbium-doped fiber amplifier with temperature, we determine the temperature. By subtracting the temperature effect from the Bragg wavelength shift, we determine the strain. Experiments show rms deviations of $18.2{\mu}{\varepsilon}$ and $0.7^{\circ}C$ for strain and temperature, respectively. 하나의 광섬유 브래그 격자와 EDFA를 이용하여 온도와 스트레인을 동시에 측정할 수 있는 센서를 제안하고 구현하였다. 혼도에 따른 EDFA 의 ASE파워의 선형적 변화를 이용하여 온도를 측정하고 전체 브래그 파장변화와 그 온도효과의 차로써 스트레인을 측정하였다. 측정값은 스트레인과 온도 각각에 대해서 $18.2{\mu}{\varepsilon}$과 $0.7^{\circ}C$의 rms 오차를 가진다.

급성 아토피 피부염 마우스 모델에서 한약조합약물의 염증반응 진정효과

정재훈,김경준,Jung, Jae-Hoon,Kim, Gyung-Jun 대한한방안이비인후피부과학회 2015 한방안이비인후피부과학회지 Vol.28 No.1

Object : The object of this study was effected of composed of 4 herbal medicines(Rubus coreanus, Rehmanniae Radix, Houttuynia cordata, Betulae cortex) on acute atopic dermatitis mice. Methods : BALB/c mice were divided 4 groups ; normal group, negative control group of acute atopic dermatitis mice induced by DNCB, treated apply to the back skin with the herbal medicine group, and treated orally with herbal medicine group. Treated with herbal medicine and DNCB during 2 weeks. After treated, measured WBCs, RBCs, and platelet in the blood, and analysed mRNA expression of spleen. Result : Composed herbal medicines could reduce WBCs, lymphocytes, monocytes, neutrophils, and eosinophils in the mouse blood. And, could down TNF-${\alpha}$ levels in spleen. In the skin tissue histology results, herbal medicines reduce the cells and T cells. Conclusion : Composed herbal medicines help to another inflammatory disease because they reduce the cells and T cells in the skin tissues. And they have inhibitory effects of TNF-${\alpha}$ mRNA expression, and Th 2 immune responses. Therefore herbal medicines use for an acute atopic dermatitis treatment.

광섬유 표면 플라즈몬 공명 센서를 이용한 스트레인 및 온도 측정

정재훈,김민욱,Jung, Jae-Hoon,Kim, Min-Wook 한국전기전자학회 2007 전기전자학회논문지 Vol.11 No.2

본 논문에서는 광섬유 표면 플라즈몬 공명 센서를 이용하여 스트레인 및 온도 변화에 따른 센서를 제시하였다. 광섬유 센서의 구조는 광섬유의 클래딩 일부를 제거하여 크롬, 은, 금을 증착한 다층 박막 구조를 모델로 하였고, dip 파장의 변화가 선형성을 보임으로써 효율적인 센서로의 활용 가능성을 보이고자 한다. This paper decribess the strain and temperature sensor using fiber optic surface plasmon resonance sensor. The sensor head is 3-layered, Cr, Ag, Au and we showed feasibility to use this sensor to measure strain and temperature.

안와 상벽 골절과 광대뼈 골절의 임상 양상과 치료 및 동반된 안과적 진단

정재훈,이화,이종미,백세현,Jae Hoon Jung,Hwa Lee,Jongmi Lee,Sehyun Baek 대한안과학회 2012 대한안과학회지 Vol.53 No.4

Purpose: To investigate the clinical manifestations, management, and ophthalmologic complications of orbital roof fractures and zygoma fractures. Methods: A retrospective survey of 119 patients who visited Korea University Medical Center from June 2009 to June 2010 was performed. The sex, age, causes, fracture characteristics, neurologic injury, ocular injury, and combined facial bone fractures of patients who were diagnosed with orbital roof fracture and zygoma fracture were statistically analyzed. Results: The mean age of patients with orbital roof fracture was 33.0 years old. The most common cause of orbital roof fracture was traffic accident (36.1%) with 6 patients receiveing surgical treatement (9.8%). Among the ophthalmologic diagnoses of the patients with orbital roof fracture, traumatic iridocyclitis was the most common (7 eyes) followed by eyeball rupture (2 eyes). The mean age of patients with zygoma fracture was 36.6 years old. The most common cause of zygoma fracture was traffic accident (32.8%), with 51 patients receiving surgical treatement (87.9%). Among the ophthalmologic diagnoses of the patients with zygoma fracture, traumatic iridocyclitis was the most common (6 eyes), followed by commotio retina (4 eyes). Conclusions: The present study regarding clinical characteristics and treatment of orbital roof fracture and zygoma fracture is helpful for ophthalmologists regarding the treatment of accompanying ophthalmologic complications. J Korean Ophthalmol Soc 2012;53(4):577-581

거대 분자운의 원적외선 특성

정재훈,김현구,김봉규,Jung, Jae-Hoon,Kim, Hyun-Goo,Kim, Bong-Gyu 한국천문학회 2006 天文學論叢 Vol.21 No.2

Infrared color-color diagram of 10 giant molecular clouds are examined to explore the dust property from the COBE Diffuse Infrared Background Experiment of the 100, 140, and $240{\mu}m$ emission. Four of them, Taurus, Mon OB1, Gem OB1, and Chameleon, show the anti-correlation in $R_{100/140}-R_{140/240}$ plot and the horizontal distribution in $R_{100/240}-R_{140/240}$ plot, which disagree with those of theoretical calculation. These could be explained by the depletion of $100{\mu}m$ and the excess of $140{\mu}m$ emission, though no existing dust model could support them. Mean color temperature of the anti-correlation region appears to be lower than that of the linear region, whose temperatures are 15.3, 17.0 K, respectively. And the linear region shows large dispersion in the plot of intensity relation. Both imply that a star formation would be more active, but not homogeneous, in the linear region compared to the anti-correlation region.

Simultaneous Measurement of Strain and Temperature by use of Fiber Bragg Grating Written in an Erbium: Ytterbium-Doped Fiber

정재훈,Jung, Jae-Hoon Institute of Korean Electrical and Electronics Eng 2004 전기전자학회논문지 Vol.8 No.1

단일 광섬유 격자와 Yb와 Er이 첨가된 광섬유를 이용한 스트레인 및 온도의 동시 측정을 시행하였다. 스트레인과 온도에 대해서 $1100\;{\mu}{\varepsilon}$ and $50-180\;^{\circ}C$ 범위에서 $55.8\;{\mu}{\varepsilon}$ 와 $3\;^{\circ}C$의 오차를 가지고 측정하였다. 본 센서의 소형 및 저가의 특성으로 미루어 볼 때 넓은 범위의 스트레인 센서로 활용가치가 높다고 사료된다. We demonstrate a fiber-optic sensor scheme, capable of the simultaneous measurement of strain and temperature using a single fiber Bragg grating written in an erbium: ytterbium-doped fiber. This novel and compact fiber grating based sensor scheme can be used for synchronous measurement of strain and temperature over ranges of $1100\;{\mu}{\varepsilon}$ and $50-180\;^{\circ}C$ with rms errors of $55.8\;{\mu}{\varepsilon}$ and $3^{\circ}C$, respectively. The simple and low-cost sensor approach has a considerable potential, particularly for wide-range strain sensing applications in which high resolution is not required.

식편압입의 발현에 관한 임상적 연구

정재훈,오상천,동진근,Jung, Jae-Hoon,Oh, Sang-Chun,Dong, Jin-Keun 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.1

The purpose of this study was to investigate the causes of food impaction and to explore solutions as well. For this study, 39 patients with food impaction were selected. 77 contact areas in these patients were investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone loss, proximal caries, marginal ridge distance and occlusal relationships. The results were as follows ; 1. Teeth without distal support were found to be the most frequent site of food impaction (41.6%). Food impaction was found to be more frequent in the upper teeth (65.2%) than the lower teeth (33.8%). 2. Food impaction was found in tight contact cases (71.4%). Alveolar bone loss was not found in the early stage of food impaction (83.1%) 3. The distance between the marginal ridges of food impaction sites (mean=0.48mm) was short-er than that of the control group. (mean=0.77mm) (p<0.001) 4. In 18.2% of the cases, proximal carries were found at the food impaction site. 5. Food impaction affected patient's occlusion with the following frequencies, cusp to marginal ridge relationship (72.7%), cusp to fossa relationship (3.9%) and stepped relationship (23.4%).