Effects of a simplified drilling protocol at 50 rpm on heat generation under water-free conditions: an in vitro study

장현지,윤진운,주지영,이주연,김현주 대한치주과학회 2023 Journal of Periodontal & Implant Science Vol.53 No.1

Purpose: In recent years, guided implant surgery has been widely used for the convenience of patients and surgeons. Further streamlining the surgical procedure would make implant surgery more convenient. Low-speed water-free conditions are often used in guided implant surgery. Therefore, in this study, we attempted to confirm once again whether drilling was safe at a low speed without water. The main purpose of this study was to evaluate whether a simplified drilling protocol that omits some intermediate steps in the drilling process was safe from the viewpoint of heat generation. Methods: D1 density artificial bone blocks were drilled under 50 rpm, 10 N·cm water-free conditions, and the surface temperature was measured using a digital infrared camera. First, drilling was performed with the sequential drilling method, which is the most widely used technique. Second, for each drill diameter, the temperature change was measured while performing simplified drilling with omission of the previous 1, 2, or 3 steps. Results: In sequential drilling, the heat generated during drilling at all diameters was less than the critical temperature of osteonecrosis (47°C) except for the ⌀2 drill. Statistical significance was observed in all groups when comparing sequential and simplified drilling in the ⌀3.2, ⌀3.8, and ⌀4.3 drills (P<0.001). However, in the simplified drilling procedures, the temperature was below the osteonecrosis threshold temperature (47°C) except for the ⌀4.3 drill with the omission of the previous 3 steps (⌀3.0, ⌀3.2, and ⌀3.8). Conclusions: In general, drilling under low-speed, water-free conditions has shown stable results in terms of heat generation. Simplified drilling showed statistically significantly greater heat generation than sequential drilling. However, most of the diameters and omitted steps seem to be clinically acceptable, so it will be useful if an appropriate selection is made according to the patient’s clinical condition.

빅데이터를 활용한 취수원 조류 발생 예측모델 개발

장현지,지연숙,김도균,김윤삼,김선주 환경독성보건학회 2019 한국독성학회 심포지움 및 학술발표회 Vol.2019 No.10

국가별 고위해성 고분자 관리제도 비교 연구

장현지,전현표,김상헌 환경독성보건학회 2023 한국독성학회 심포지움 및 학술발표회 Vol.2023 No.11

Herpes Zoster with Aseptic Meningitis in Immunocompetent Children: A Case Series

장현지,유혜원,윤리라,공주현,이윤진,남상욱,김영미 대한소아신경학회 2017 대한소아신경학회지 Vol.25 No.4

Primary clinical features of rash and neurological complications due to varicella zoster virus (VZV) reactivation are rare in a healthy population, especially in immunocompetent children. Early diagnosis and prompt treatment are delayed often due to their rarity. We present four immunocompetent children with VZV reactivation resulting in aseptic meningitis and herpes zoster affecting multiple cranial and spinal nerves. We reviewed the clinical manifestations, laboratory findings, treatment options and outcome of aseptic meningitis associated VZV reactivation. All patients presented with the typical skin lesion of VZV reactivation and definitive laboratory findings of central nervous system infection, without systemic inflammation. Initial manifestations of VZV reactivation included Ramsay Hunt syndrome, herpes zoster ophthalmicus, and herpes zoster affecting the left thoracic dermatomes 4-5. Intravenous acyclovir was administered and all patients recovered fully without any significant sequelae. VZV reactivation can lead to various neurological complications in immunocompetent children. Early recognition and treatment with acyclovir are important for improving the outcome of neurologic complications of VZV reactivation.

뉴스 텍스트 데이터를 활용한 사용자 정의 감성사전 구축

장현지 성균관대학교 응용통계연구소 2022 통계연구 Vol.22 No.-

본 연구에서는 한국경제 신문의 뉴스 기사 스크래핑 데이터와 개인 투자자의 KOSPI 순매수대금 데이터를 사용하여 주가 예측에 활용할 수 있는 주가 감성 사전의 구축을 시도한다. Python의 KoNLPy 패키지를 사용하여 뉴스 기사의 형태소 분석을 진행하고, TF-IDF 방법을 통해 유의미한 단어들의 중요도를 추출한다. 이후 개인 투자자의 KOSPI 순매수대금을 반응변수로 하여 릿지(Ridge) 회귀를 적합하면 그 결과 얻어지는 회귀 계수가 각 단어들의 감성 점수가 되며, 이를 활용해 특정 날짜의 주가 감성 점수를 도출해낼 수 있다.

Pulmonary Metastasis Originated from Uterine Sarcoma, Presenting as Multiple Nodules with Tortuous, Serpentine, Aneurysmal, Dilated Intratumoral Vessels: A Case Report

장현지,김성수,박희선,이정은,김진환 대한영상의학회 2018 대한영상의학회지 Vol.78 No.4

Pulmonary metastases present a wide spectrum of radiological findings, some of which have been known to be useful for analogizing the possible origin or site of primary tumors. In the present report, we describe a unique case of pulmonary metastasis manifesting on chest computed tomography as multiple nodules with tortuous, serpentine, aneurysmal, dilated, inner intratumoral vessels. The metastasis originated from uterine sarcoma.

대학생의 사회적 지지가 진로준비행동에 미치는 영향과 성찰학습의 매개효과

장현지,홍아정 한국직업교육학회 2014 職業 敎育 硏究 Vol.33 No.2

As the university graduates' unemployment has become one of the critical issues in Korean society, various efforts for its solution has been offered. In this regard, the purpose of this study was to examine the influence of social support upon university students’ career preparation behavior and reflective learning. The study analysed the relationship between social support and career preparation behavior, and the mediating effect of students' reflective learning. 424 university students of Seoul and Metropolitan area were surveyed. The findings of the study showed that there is a positive relation with students' perception of social support and career preparation behavior, and students' reflective learning has a partial mediation effect between the two variables. The result implies that students who perceive higher social support will enhance their reflective learning level in which will eventually engage them actively in their career preparation behavior. Thus, in order to enhance university students' career preparation behavior, it is important to make them feel encouraged with tangible as well as emotional support. Also, educational support for students' reflective learning should be provided in higher education institutions and programs to advance students' career development. 대졸 청년의 실업률 증가가 우리 사회의 심각한 문제로 대두되고 있는 가운데 대학생 취업을 촉진하기 위한 노력이 다각적인 측면에서 이루어지고 있다. 이에 본 연구에서는 주변에서 지원과 도움을 많이 받았다고 지각한 학생일수록 성찰학습과 진로준비행동이 향상될 것이라는 가설 하에 대학생의 사회적 지지가 진로준비행동에 미치는 영향을 살펴보고, 특히 성찰학습이 이들 관계에서 매개효과를 갖는지 검증하였다. 연구 목적을 달성하기 위해 서울‧수도권 소재 4년제 대학생 419명을 대상으로 설문조사를 하였고, 분석결과는 다음과 같다. 첫째, 대학생들의 진로준비행동 중 정보수집행동에는 정서적 지지, 정보적 지지, 물질적 지지, 평가적 지지가 모두 영향을 미치며, 도구구비행동에는 사회적 지지 중에서 정보적 지지가 긍정적인 영향을 미치는 것으로 나타났다. 목표달성행동에는 물질적 지지가 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 대학생들의 성찰학습은 사회적 지지와 진로준비행동의 관계에서 부분매개를 하는 것으로 나타났다. 이러한 연구결과를 통해 대학생들의 구체적인 진로준비행동을 향상시키기 위해서는 자신과 주변 환경을 비판적으로 성찰할 수 있는 능력을 키워주는 것이 중요하고, 더불어 성찰학습을 향상시키기 위해서는 유용하고 질 좋은 정보를 적절히 제공하는 것은 물론 진로 목표달성을 위해 다각적인 경제적, 물질적 지원의 확대가 필요함을 확인할 수 있다.

컨테이너 이미지 취약점 분석 도구의 성능 비교 연구

장현지(Hyeounji Jang),이혁진(Hyeock-Jin Lee),김직수(Jik-Soo Kim) 한국정보과학회 2021 한국정보과학회 학술발표논문집 Vol.2021 No.12

Python을 이용한 GUI 기반의 4축 제어 시스템 설계 및 제작

장현지(Hyeon-Ji Jang),박승범(Seung-Bum Park),김지원(Ji-Won Kim),유은서(Eun-Seo You),이동욱(Dong-Wuk Lee),이승대(Seung-Dae Lee) 한국전자통신학회 2024 한국전자통신학회 논문지 Vol.19 No.1

정밀 설비 기술의 발전으로 4축 CNC 정밀 가공 기술의 중요성이 증대되고 있다. 그러나, 복잡한 형상 가공으로 인해 시스템 구동은 어려운 실정이다. 본 논문은 이러한 문제를 해결하기 위해 4축 제어 구조물을 제작하고, 상용 프로그램을 이용없이 Bresenham's Line Algorithm과 Runspeed Algorithm을 구현하여 정밀 제어 및 효율성을 비교하였다. Runspeed를 적용할 경우 Bresenham 대비 약 12.03%의 오차 개선과 곡률 정밀도 향상이 있었으며, 회전축 A모터를 구동하여 입체 구조물에도 정밀한 가공이 가능함을 확인하였다. With the development of precision facility technology, the importance of four-axis CNC precision processing technology is increasing. However, due to complex shape processing, it is difficult to operate the system. This paper compared precision control and efficiency by manufacturing a four-axis control structure to solve this problem and implementing Bresenham's Line Algorithm and Runspeed Algorithm without using commercial programs. When Runspeed was applied, there was an error improvement of about 12.03% and curvature accuracy improvement compared to Bresenham. It was confirmed that precise processing was possible to a three-dimensional structure by driving a rotary shaft A motor.

조직원 간 대인 커뮤니케이션이 기업명성에 미치는 영향 -조직-사원 관계성 및 조직 동일시의 매개효과

장현지 ( Hyun Ji Jang ),차희원 ( Hee Won Cha ) 한국PR학회 2013 PR연구 Vol.17 No.4

This study analyzed how much impact communication among superiors or co-workers have on the corporate reputation. It also researched mediation effect, setting the employee-organization relationship and organizational identification as mediating variables to specify the process of how communication among employees would have effect on the corporate reputation. The results showed that the composure from communication with superiors had a direct and significant effect on the corporate reputation. The mediation effect of the employee-organization relationship was significant though no mediation effect of organization identification was found. This study proved that interpersonal communication with superiors was the main variable that affected the reputation through empirical research and found significant causal relationship among interpersonal communication, the employee-organization relationship, organizational identification and reputation.