Numerical Study on Wave Run-up of a Circular Cylinder with Various Diffraction Parameters and Body Drafts

정호진,구원철,김성재 한국해양공학회 2020 한국해양공학회지 Vol.34 No.4

Wave run-up is an important phenomenon that should be considered in ocean structure design. In this study, the wave run-up of a surface-piercing circular cylinder was calculated in the time domain using the three-dimensional linear and fully nonlinear numerical wave tank (NWT) techniques. The NWT was based on the boundary element method and the mixed Eulerian and Lagrangian method. Stokes second-order waves were applied to evaluate the effect of the nonlinear waves on wave run-up, and an artificial damping zone was adopted to reduce the amount of reflected and re-reflected waves from the sidewall of the NWT. Parametric studies were conducted to determine the effect of wavelength, wave steepness, and the draft of the cylinder on the wave run-up of the cylinder. The maximum wave run-up value occurred at 0°, which was in front of the cylinder, and the minimum value occurred near the circumferential angle of 135°. As the diffraction parameter increased, the wave run-up increased up to 1.7 times the wave height. Furthermore, the wave run-up was 4% higher than the linear wave when the wave steepness was 1/35. In particular, the crest height of the wave run-up increased by 8%.

Pneumocephalus due to Compressed Air Injury without Facial Bone Fracture

정호진,이병훈,황윤준,김수영 대한영상의학회 2011 대한영상의학회지 Vol.65 No.4

Pneumocephalus without a facial bone fracture or sinus disease is rare. A possible cause of pneumocephalus is high-pressure air applied into the orbit may cause without any evidence of a facial fracture (1-5). The mechanism behind pneumocephalus may be secondary to a blast of air from the orbit to the intracranial space (1, 2) with a degree of pressure (1). We report a case of compressed air injury induced by disseminated pneumocephalus in the absence of a facial bone fracture detected on multidetector computed tomography. After 5 days, a follow-up indicated that the pneumocephalus was almost completely resolved without visual loss.

가족동거여부가 치과진료 수진률에 미치는 영향 : 제7기 국민건강영양조사 이용

정호진,김경민 대한통합의학회 2023 대한통합의학회지 Vol.11 No.4

Purpose : Although Korea’s health insurance system and access to medical care are well established compared to other countries, the rate of non-fulfillment of dental treatment is high. Medical use rates can be affected by economic characteristics, individual heatlh condtions, health concerns, and health behaviors. This study was implemented to investigate the effect of the middle-aged elderly people’s family living together on the dental examination rate and to use it as basic data for program development, research, and poicies to promote oral health. Methods : Raw data from the 7th national health and nutrition survey conducted by the Korea centers for disease control and prevention (2016~2018) were used and analyzed using SPSS 21.0 Version (IBM, United States). Results : As a result of the study family types accroding to general characteristics, the more women are (p<.001), the higther the age (p<.001), the lower the hosehold income level (p<.001), the lower the educational background (p<.001), the more people who live in Eup-Myeon (p<.001) It was fouend that the rate of living alone was high. The dental examination rate according to general characteristics was related to age (p<.001), income (p<.001), and educational background (p<.001), and the higher the examination rate was in the same (p<.001), and the higher the family living together (p<.001). Factors influencing whether or not dental treatment was not performed were in the following order: household income (p<.001), age (p=.001), and family type (p=.017). Conclusion : The above results confirmed the relationship between family membership and dental examination rates, and measures such as the development and operation of participatory programs to improve public oral health by resolving medical inequality and enhancing health equity, and it is believed that the development of professional manpower and the operation of education and programs for professionals are necessary.

[농사꾼의 눈으로 읽는 성서] 땅은 우리네 생명의 터전 : 창세기 1 : 11-12, 1:26-28

정호진 제3시대그리스도교연구소 2000 시대와 민중신학 Vol.6 No.-

파워쉘 기반 악성코드에 대한 역난독화 처리와 딥러닝 기반 탐지 방법

정호진,유효곤,조규환,이상근 한국정보보호학회 2022 정보보호학회논문지 Vol.32 No.3

2021년에는 코로나의 여파로 랜섬웨어를 활용한 공격이 유행했으며 그 수는 매년 급증하고 있다. 그 중 파워쉘은 랜섬웨어에 주요 기술로 사용되고 있어 파워쉘 기반 악성코드 탐지 기법의 필요성은 증가하고 있으나 기존의 탐지 기법은 난독화가 적용된 스크립트를 탐지하지 못하거나 역난독화에 시간이 오래 소요되는 한계가 존재한다. 이에 본 논문에서는 간단하고 빠른 역난독화 처리과정, Word2Vec과 CNN(Convolutional Neural Network)으로 구성되어 스크립트의 의미를 학습하고 특징을 추출해 악성 여부를 판단할 수 있는 딥러닝 기반의 분류 모델을 제안한다. 2021 사이버보안 AI/빅데이터 활용 경진대회의 AI 기반 파워쉘 악성 스크립트 탐지 트랙에서 제공된 1400개의 악성코드와 8600개의 정상 스크립트를 이용하여 제안한 모델을 테스트한 결과 기존보다 5.04배 빠른 역난독화 실행 시간, 100%의 역난독화 성공률, 0.01의 FPR(False Positve Rate), 0.965의 TPR(True Positive Rate)로 악성코드를 빠르고 효과적으로 탐지함을 보인다.

흡착원자의 덮임율에 따른 Ag/Si(111)√3X√3의 구조 변화

정호진,정석민,Jeong, Ho-Jin,Jeong, Suk-Min 한국진공학회 2008 Applied Science and Convergence Technology Vol.17 No.5

Using a first-principles total-energy method, we investigate structural and energy changes on Ag/Si(111)$\sqrt{3}{\times}\sqrt{3}$($\sqrt{3}-Ag$ hereafter) as the number of the additional Ag adatoms increases. The Ag coverage varies from 0.02 to 0.14 ML. Most Ag adatoms occupy the ST site, which is the center of small triangles of the substrate Ag layer that is composed of small and large triangles. One of the interesting adsorption features is that the adatoms immerse below the substrate layer. The total energy calculations show that the clusters become the most stable when the number of Ag atoms is three. This three-Ag cluster becomes the building block of the $\sqrt{21}{\times}\sqrt{21}$ phase that shows a large surface conductivity. The simulated STM images show that the adatoms look dark in filled-state images while bright in empty-state images. This suggests that the adatoms donate their charge to the substrate. The simulated STM images agree well with the experimental images.

초등학교 야구 선수의 수직 점프 및 다리 근력 간 상관관계에 대한 융합연구

정호진,박세주,Jeong, Ho-Jin,Park, Se-Ju 한국융합학회 2021 한국융합학회논문지 Vol.12 No.8

The purpose of this study was to investigate the relationship between vertical jump and lower extremity muscle strength of elementary school baseball players. This study subjects were conducted with a total of 40 subjects. Vertical jump was measured using a vertical jump gauge, and a hand held dynamometer was used to measure lower extremity muscle strength. For the measurement of lower extremity muscle strength, flexion·extension·adduction·abduction·internal rotaiton·external rotation of both hip joint, flexion·extension of both knee joint, dorsi flexion·plantar flexion of both ankle joint were measured. pearson's correlation analysis was used to analyze the correlation between vertical jump and lower extremity muscle strength. From these results, it was found that the stronger the leg muscles except for the plantar flexion, the higher the vertical jump was, indicating a positive correlation. In future studies, follow-up studies on the relationship between batting ability and vertical jump & lower extremity muscle strength are needed.

Effects of Applying a Vibration Stimulation to Paretic Side and Non-Paretic Side on Balance and Gait in Stroke Patients: a Pilot Study

정호진,박성환,Jong Yun Jeon,김병근 대한물리치료학회 2022 대한물리치료학회지 Vol.34 No.5

Purpose: The purpose of this pilot study was to assess the feasibility of a proposed study “To investigate the effects of applying a vibration stimulation to the paretic and non-paretic sides on balance and gait in stroke patients” before proceeding with the main study. Methods: A total of 30 patients who had suffered a stroke and who met the selection criteria participated in this study. However, only 14 patients completed the study. The study subjects were randomly assigned to vibration stimulation on either both sides (B group) or the paralyzed side (P group). The interventions were applied for six weeks. The patients were assessed using the Berg balance scale (BBS), Timed up and go (TUG), 10-meter walk (10 MW), and 6-minute walk (6 MW) tests. Results: There was a significant difference before and after the application of vibration stimulation in the BBS, TUG, 10MW, and 6 MW tests in the B group (p<0.05). Similarly, there was also a significant difference observed in the 10 MW and 6 MW tests in the P group (p<0.05). The difference between the two groups was not significant in the BBS, TUG, 10 MW, and 6 MW tests (p>0.05). Conclusion: This pilot study suggests that it would be feasible to conduct a large-scale randomized controlled trial (RCT) to examine the effects of applying a vibration stimulation to the paretic and non-paretic sides, on the balance and gait in stroke patients.

PTPRD (Protein Tyrosine Phosphatase Receptor Type Delta) 유전자 다형성과 조현병에서 항정신병약물에 의한 하지불안증후군

정호진,조철현,강승걸,이헌정 대한조현병학회 2014 대한조현병학회지 Vol.17 No.1

Objectives : The previous genome-wide association studies have revealed several candidate genes for restless legs syndrome (RLS). The PTPRD (protein tyrosine phosphatase receptor type delta) gene is one of the candidate genes for RLS. The occurrence of antipsychotic-related RLS could also be attributable to differences in genetic susceptibility. This study aimed to investigate whether PTPRD polymorphism is associated with antipsychotic-related RLS in schizophrenia. Methods : We assessed symptoms of antipsychotic-induced RLS in 190 Korean schizophrenic patients and divided the subjects into two groups according to the International Restless Legs Syndrome Study Group diagnostic criteria : (i) subjects that met all of the criteria (n=44) and (ii) the remaining subjects who were not considered to be RLS patients (n=146). PTPRD rs462664 was genotyped by PCR in 190 individuals. The χ2-test was performed to compare differences between two groups. Results : The frequencies of genotype (χ2=1.31, p=0.519) of the PTPRD rs462664 did not differ significantly between schizophrenic patients with and without RLS. The difference of allele frequencies (χ2=1.30, p=0.25) of the PTPRD rs462664 between the schizophrenic patients with and without RLS were not significant. Conclusion : These results suggest that PTPRD gene polymorphism does not play a major role in susceptibility to antipsychotic-related RLS in schizophrenia. This finding suggests that antipsychotic-induced RLS may have a different pathogenesis compared to primary RLS.

장·노년층의 저작불편감에 영향을 주는 요인 : 제8기 국민건강영양조사 이용

정호진 대한통합의학회 2024 대한통합의학회지 Vol.12 No.2

Purpose: This study utilizes big data from the 8th (2021) National Health and Nutrition Examination Survey to determine first, the relationship between chewing discomfort in the elderly and some systemic diseases and second, whether oral diseases and oral health problems are related to systemic diseases. Since this may have an impact, we aim to provide basic data to facilitate the expansion and emphasize the importance of integrated health management education. Methods: Original data from the 8th (2021) National Health and Nutrition Survey, conducted by the Korea Centers for Disease Control and Prevention, were analyzed using SPSS Version 21.0 (IBM). A complex sample frequency analysis was conducted to confirm the general and health-related characteristics of the study subjects, and a complex sample cross-analysis was conducted to determine chewing discomfort according to both general and health-related characteristics. Complex sample multiple logistic regression analysis was conducted to determine the effect on chewing discomfort. Results: In order to analyze the factors that affect chewing discomfort, the general characteristics that showed significant differences in chewing discomfort were adjusted for age, personal income, education level, basic livelihood security, high blood pressure, subjective health status, and subjective oral health. It was found that the condition had a statistically significant effect on chewing discomfort. Conclusion: The findings of this study demonstrate that high blood pressure, subjective health status, and subjective oral health status affect chewing discomfort; hence, measures such as developing and operating programs to improve national oral health are needed. We hope that our study will be used as basic data for research into chewing discomfort and systemic diseases in the elderly.