• Title/Summary/Keyword: 김훈

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A Study on the Non-Contact Detection Technique of Defects Using AC Current - The Influence of Frequency and lift-off - (교류전류를 이용한 비접촉결함탐상법에 관한 연구 - 주파수 lift-off의 영향 -)

  • Kim, Hoon;Na, Eu-Gyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.22 no.1
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    • pp.53-58
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    • 2002
  • New nondestructive inspection (NDI) technique to detect the defect in metal was developed in which an electromagnetic field is induced in a metal by AC current flowing in the magnetic coil and the leak magnetic-flux disturbed by defects is measured using a tape-recorder head with air gap. This technique can be applied in evaluating the location and sizing of surface defects in components of the ferromagnetic body by means of the non-contacting measurement. In this paper, we have applied this technique to the evaluation of two-dimensional surface cracks in ferromagnetic metal, and also investigated the influence of the various frequencies and lift-off. Defects were detected with maximum values in the distribution of voltage and it was found that the maximum values tend to increase with the defect depth. Although the maximum values for defects are affected by the frequency and lift-off, the depth of small defects can be estimated from the linear relationship between the depth and voltage rate$(V_0/V_{ave})$.

A Case of Cerebrospinal Fluid Leakage Repair with Forearm Free Flap after Craniofacial Resection of Sinonasal Undifferentiated Carcinoma (비부비동 미분화암의 두개안면절제술 후 전완부자유피판을 이용한 뇌 척수액 유출 폐쇄 시행 1례)

  • Song, Kee Jae;Cho, Jin Mo;Jung, Woon-Yong;Kim, Hoon;Hong, Hyun Jun
    • Korean Journal of Head & Neck Oncology
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    • v.32 no.2
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    • pp.91-94
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    • 2016
  • A 37 year-old male presented with sudden right proptosis and bilateral nasal obstruction. A huge tumor was noted in bilateral nasal cavities, ethmoid sinuses and central frontal sinus on magnetic resonance imaging. Right posterior frontal sinus wall and bilateral medial orbital wall was destructed by the tumor. Complete resection of the tumor was performed via minimal invasive craniofacial resection. Histopaghologic examination revealed sinonasal undifferentiated carcinoma (SNUC). Cerebrospinal fluid leakage was developed after 2 days of the surgery. On the 5th day, anterior skull base was reconstructed with forearm free flap (FFF). The patient got 6000cGy of radiotherapy and survived in 27 months of follow up.

The Correlation between Stool Exams and Abdominal Computed Tomography (CT) Findings in the Patients with Acute Diarrhea Visiting Emergency Department (ED)

  • Ha, Minseok;Kwack, Chi Hwan;Kang, Jun Ho;Han, Kyu Hong;Min, Jin Hong;Park, Jung Soo;Lee, Suk Woo;Kim, Hoon
    • Journal of The Korean Society of Emergency Medicine
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    • v.26 no.1
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    • pp.29-37
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    • 2015
  • Purpose: Stool exams are a useful tool for the early presumptive diagnosis of infectious bacterial diarrhea in the Emergency Department (ED). CT scans are often used to increase the physician's level of certainty and to facilitate patient triage by identifying the source of pain in most patients with an acute abdomen in the ED. This study was designed to investigate the correlation between stool exams and abdominal CT in patients with acute diarrhea visiting the ED. Methods: We conducted a retrospective study in the emergency department of a national university hospital from January 1, 2012 to June 30, 2013. The subjects consisted of 156 patients with acute diarrhea and abdominal pain who had stool exam results and abdominal CT findings. We divided the patients into three groups according to the stool exam results. Simultaneously, we evaluated their CT findings of the bowel and adjacent structures. Results: A total of 156 patients were enrolled. Frequency of abnormal CT findings showed statistically significant correlation with stool exams (p-value <0.001). Abnormal CT findings increased as WBCs and RBCs in stool increased (p-value <0.001). Conclusion: The stool exam was a statistically significant predictive variable in indirectly determining the severity of acute diarrhea and it showed correlation with the frequency of abnormal CT findings. It is suggested that stool exams can be used as a susceptible marker for predicting the probability of severe infectious colitis, and for making an early decision regarding close medical attention.

A Case of Malignant Melanoma During Hormone Therapy (폐경기 호르몬 치료 중 발생한 악성 흑색종 1례)

  • Sung, Jung-Yeob;Kim, Hoon;Kim, Yong-Jin;Ku, Seung-Yup;Kim, Seok-Hyun;Choi, Young-Min;Kim, Jung-Gu;Moon, Shin-Yong
    • Clinical and Experimental Reproductive Medicine
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    • v.36 no.3
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    • pp.225-230
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    • 2009
  • Over the last several decades, the incidence of malignant melanoma has been increasing rapidly. The annual incidence rates have increased approximately 3~7% in Caucasian population. The rate of increase is highest in perimenopausal period in women. The relationship between risk of melanoma and female hormone is still unclear. The safety of hormone therapy for the melanoma patients is not known. We experienced a case of melanoma in whom underwent hormone therapy for 10 years. We report this case with a brief review of literature.

Modeling Technology on Free-form Surface of a New Military Personal Head using Quick Surface Method (퀵서피스기법을 이용한 신장병 두상의 자유곡면 모델링 기술)

  • Lee, Yong-Moon;Hwang, Tae-Son;Kim, Hun;Nam, Hee-Tae;Lee, Kee-Hwan;Kang, Myungchang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.170-176
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    • 2018
  • Recently, weapon system requires personal protection products due to the explosion of rapid-fire explosion, which is considered to be multi threat in modernization, complication and war against terrorism. However, the conventional Korean military bullet protection helmets are not suitable for wearing convenience and combatant interoperability in terms of ergonomic. In this paper, we propose a suitable 3D Scanning method for the head, and compare the measured 3D dimension with the existing 2D measurement value to identity the reliability. Reverse engineered soldier head using the quick surface method was realized with a perfect free-form surface and satisfactory tolerance range (${\pm}0.2mm$). Through the comparison of 3D and 2D measured head dimensions, the absolute error value was 0.73 mm on average and relative error was 0.35 %, confirming the high accuracy of the 3D scan modeling. Also, quick surface method using 3D scanner is suggested a fast and accurate skill for ergonomics in obtaining the head modeling needed for military's personal bullet protection helmet design.

Effect of regional climatic conditions, air pollutants, and season on the occurrence and severity of injury in trauma patients

  • Kim, Young-Min;Yu, Gyeong-Gyu;Shin, Hyun-Jo;Lee, Suk-Woo;Park, Jung-Soo;Kim, Hoon
    • Journal of The Korean Society of Emergency Medicine
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    • v.29 no.6
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    • pp.603-615
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    • 2018
  • Objective: We analyzed the association between regional weather and temporal changes on the daily occurrence of trauma emergencies and their severity. Methods: In this cross-sectional prospective study, we investigated daily atmospheric patterns in trauma episodes in 1,344 patients in Cheongju city, South Korea, from January 2016 to December 2016 and analyzed the association of trauma occurrence and Injury Severity Scores (ISS) with weather conditions on a daily scale. Results: The mean age of trauma patients was $53.0{\pm}23.8years$ and average ISS was $9.0{\pm}2.0$. Incidence of trauma was positively correlated with average temperature (r=0.512, P<0.001) and atmospheric pressure (r=0.332, P=0.010) and negatively correlated with air pollutants (particulate matter less than $2.5{\mu}m^3$ [PM2.5], r=-0.629, P<0.001; particulate matter less than $10{\mu}m^3$ [PM10], r=-0.679, P<0.001). ISS was not significantly correlated with climate parameters and air pollutants, and variability was observed in the frequency and severity of trauma by time of day (highest occurrence, 16-20 pm; highest ISS, 4-8 am), day of the week (highest occurrence and highest ISS, Saturday), month of the year (highest occurrence, July; highest ISS, November), and season (highest incidence, summer; highest ISS, autumn). Conclusion: The study shows a positive relationship between trauma occurrence and specific weather conditions, such as atmospheric temperature and pressure. There was a negative relationship between concentrations of PM2.5 or PM10, and trauma occurrence. However, no correlation was observed between weather conditions or the concentrations of air pollutants and ISS. In addition, seasonal, circaseptan, and circadian variations exist in trauma occurrence and severity. Thus, we suggest that evaluation of a larger, population-based data set is needed to further investigate and confirm these relationships.

Manufacture and evaluation of hydrogel preparations that are easy to use in emergency allergy situations (응급알레르기 상황에서 사용하기 쉬운 하이드로겔 제제의 제조 및 평가 과정)

  • Kim, Chul-tae;Kim, Hoon
    • Journal of Digital Convergence
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    • v.19 no.3
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    • pp.287-293
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    • 2021
  • Tablets were conventionally used to treat choline urticaria. Disadvantages of tablets included sleep inducing problems, accessibility and reduced dosage. To address this, hydrogel containing Cetirizine HCl was manufactured. The experimental method was to measure viscosity, gel fraction, degree of swelling, content evaluation, and permeability. Studies have shown that hydrogels containing Cetirizine HCl can be directly applied to occurrence area to improve Cholinergic urticaric with minimal side effects associated with the marketable tablets. This hydrogel includes other important substances including steroids which gives it an advantage when applied on the skin, improving its accessibility. In addition, it is expected that the drug manufacturing process will be able to proceed as this hydrogel is effective even when used alone.

Impact of Solar Irradiance on the Receiver Sensitivity of Free-Space Optical Communication Systems (주광이 무선 광통신 시스템의 수신 감도에 미치는 영향)

  • Park, Gihong;Kim, Hoon
    • Korean Journal of Optics and Photonics
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    • v.31 no.6
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    • pp.259-267
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    • 2020
  • We evaluate the degradation of receiver sensitivity induced by direct and indirect exposure to solar irradiance in free-space optical communication systems. For this purpose, we calculate the variances of numerous noise components arising from solar irradiance, and then estimate the receiver sensitivity penalties for intensity-modulation/direct-detection and coherent systems. The results show that the penalties are less than 1.3 dB when indirect sunlight impinges on the detector, regardless of the system. However, the sensitivity penalties are estimated to be larger than 30 dB when the sunlight is directly incident upon the receiver. These penalties are barely reduced if we insert an optical polarizer, or if we adjust the bandwidth of an optical filter at the receiver to be as narrow as the signal's bandwidth.

HPLC/UV Quantification of (+)-Catechin in Filipendula glaberrima from Different Regions and Flowering Stages (터리풀의 채집장소 및 채집시기에 따른 카테킨 함량 HPLC/UV 분석)

  • Lee, Hak-Dong;Lee, Yunji;Kim, Hoon;Kim, Hangeun;Park, Chun-Gun;Lee, Sanghyun
    • Korean Journal of Pharmacognosy
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    • v.51 no.4
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    • pp.291-296
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    • 2020
  • Filipendula glaberrima (FG) is a plant endemic to South Korea. It is economically important as a food source and used as a medicine in treating ailments. Filipendula flowers are characterized by the presence of several polyphenolic constituents. The aim of this study is to determine the content of (+)-catechin in Filipendula glaberrima collected from different regions at different flowering stages. High-performance liquid chromatography with a gradient elution system (0.5% acetic acid in water : acetonitrile = 95 : 5 to 0 : 100 for 35 min) was used. A reverse-phase INNO column with UV detection at 278 nm was employed. The results revealed that F. glaberrima from Mt. Odae has the highest (+)-catechin content (10.600 mg/g). Furthermore, its content was the lowest in samples collected during the pre-flowering period and the highest at the early-flowering stage. This study provides a basis in establishing the optimal period and the best region for collecting F. glaberrima with maximized (+)-catechin yield.

The Physiological Activity of Crude Polysaccharide Solvent Extracted from Herbal Medicine Mixture (생약복합물 용매추출물과 조다당획분의 생리활성)

  • Shin, Hyun-Young;Kim, Hoon;Shin, Ji-Young;Lee, Sue Jung;Yu, Kwang-Won
    • The Korean Journal of Food And Nutrition
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    • v.34 no.1
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    • pp.36-46
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    • 2021
  • After ethanol (BM-E and RW-E) and hot-water (BM-HW and RW-HW) extracts were fractionated from two herbal mixtures (BM and RW), their physiological activities were investigated. All extracts consisted of more than 50% of neutral sugar, with their total polyphenol levels higher than flavonoid levels. Radical scavenging activities of EtOH extracts remained significantly higher compared to that of hot-water extracts, and in particular, RW-E showed consistently higher antioxidant activity than BM-E. When anti-inflammatory activities of the extracts were evaluated by LPS-stimulated RAW 264.7 cells at 10~500 μg/mL non-cytotoxicity doses, BM-E showed significantly higher levels of TNF-α, IL-1β, IL-6, and nitric oxide inhibitory activity than those of hot-water extracts and RW-E. Murine peritoneal macrophage cells were shown to be enhanced in crude polysaccharides (BM-CP and RW-CP fractionated from BM-HW and RW-HW) compared to hot-water extracts and polysaccharide K (PSK, positive control). Especially, RW-CP exhibited higher activity than BM-CP, and component sugar analysis showed that BM-CP mainly contained galacturonic acid, glucose, arabinose, galactose, and xylose (34.5%, 33.9%, 16.1%, 7.1%, and 6.3%, respectively), whereas RW-CP showed different measurements (29.5%, 59.2%, 5.0%, 4.5%, and 0.2%). In conclusion, two herbal mixtures could contain varying sets of physiological activities dependent on different extraction and fractionation methods.