공기 중 광대역 초음파 방사용 압전 박막 기반 초소형 초음파 트랜스듀서의 설계

안홍민,진재혁,문원규 한국음향학회 2020 韓國音響學會誌 Vol.39 No.2

In this paper, the design of piezoelectric Micro-machined Ultrasonic Transducer (pMUT) for wideband ultrasonic radiation in air was investigated. One of the methods to achieve wide frequency bandwidth in single device is modeling the transducer to multi-resonance system. The new pMUT was designed as a multi-resonance system with the addition of a suitable acoustic structure to the front and back of a thin film structure. A new pMUT consisting of thin film parts, radiation parts, and packaging parts is designed with a Lumped Parameter Model (L.P.M). Finally, it was validated as a Finite Element Method (FEM) simulation. The final designed pMUT achieved a frequency band of 102 kHz ~ 132 kHz (-3 dB). 본 논문에서는 공기 중 광대역 초음파 방사용 압전 박막 기반 초소형 초음파 트랜스듀서(piezoelectric Micro-machined Ultrasonic Transducer, pMUT)의 설계 연구가 진행되었다. 하나의 트랜스듀서로 광대역을 달성하 는 방법 중 하나는 다공진 시스템으로 설계하는 것이다. 새로운 pMUT은 박막 구조의 앞면과 뒷면에 적절한 음향 구조 를 추가하여 다공진 시스템을 구현하도록 설계되었다. 박막 앞쪽은 도파관 구조로 모델링된 방사 파트로, 박막 뒷쪽은 음향 공동으로 모델링된 패키징 파트로 이루어져있다. 박막 파트, 방사 파트, 패키징 파트로 구성된 새로운 pMUT은 집중 변수 모델로 설계되었으며, 최종적으로 유한요소해석으로 검증되었다. 최종 설계된 pMUT은 102 kHz ~ 132 kHz (-3 dB)의 주파수 대역을 달성하였다.

Impending Rupture With a Twisted Huge Appendiceal Mucocele Treated With Totally Laparoscopic Resection: A Case Series

안홍민,이시학 대한대장항문학회 2021 Annals of Coloproctolgy Vol.37 No.S

Torsion of the appendix is rare, and appendiceal mucocele can be one of its causes. The first case was of a 49-year-old man who visited the emergency room (ER) for abdominal pain. Abdominal computed tomography (CT) showed appendiceal mucocele with suspected torsion and rupture. The patient underwent laparoscopic exploration and appendectomy. The second case was of a 69-year-old man who visited the ER for epigastric pain. Abdominal CT showed suspicious appendiceal mucocele with ischemic change, indicating torsion of the appendix. The twisted appendix was successfully removed by laparoscopic exploration. An appendiceal mucocele is one of the causes of twisted appendix. With torsion, the mucocele can be diagnosed as rupture by ischemia which may lead to pseudomyxoma peritonei. For this reason, open laparotomy has traditionally been preferred. However, an unruptured appendiceal mucocele or impending rupture with torsion of the appendiceal mucocele can be treated with totally laparoscopic surgery.

Clinical features of internal hernia after gastrectomy for gastric cancer

안홍민,이시학,전태용,김대환,최창인,김수진,최철웅,김태언,김기현,황선휘 대한내시경복강경외과학회 2021 Journal of Minimally Invasive Surgery Vol.24 No.1

Purpose: Internal hernia after gastrectomy is a rare but potentially life-threatening condition without surgical intervention. Clinical risk factors of internal hernia should, hence, be reviewed after gastrectomy. From 2008 to 2018, patients who underwent gastrectomy for gastric cancer were investigated. Methods: Abdominal computed tomography (CT) was used to screen for internal hernia, and surgical exploration was performed to confirm the diagnosis. Using retrospective statistical analysis, the incidence, characteristics, and risk factors were identified, and the characteristics of the internal hernia group were reviewed. Results: The overall incidence of internal hernia was 0.9%. From statistical analysis, it was found that laparoscopic surgery was almost five times riskier than open gastrectomy (odds ratio [OR], 4.947; 95% confidence interval [CI], 1.308–18.710; p = 0.019). Body mass index < 25 kg/m2 (OR, 4.596; 95% CI, 1.056– 20.004; p = 0.042) and proximal gastrectomy (OR, 4.238; 95% CI, 1.072–16.751; p = 0.039) were also associated with internal hernia. Among 20 patients with internal hernia, 12 underwent laparotomy, and five had their bowels removed due to ischemia. All patients with bowel resected had suffered from short bowel syndrome. Conclusion: Suspecting an internal hernia should be an important step when a patient with a history of laparoscopic gastrectomy visits for medical care. When suspected, emergent screening through CT scan and surgical intervention should be considered as soon as possible to prevent lifetime complications accordingly.

건설안전 실무 - 갱폼사고방지를 위한 안전작업

안홍민,An, Hong-Min 대한산업안전협회 2012 안전기술 Vol.173 No.-

원자력발전소 시뮬레이터 데이터의 패턴인식을 이용한 압력경계기기 고장 진단 연구

안홍민,최현우,강성기,채장범,Ahn, Hongmin,Choi, Hyunwoo,Kang, Seongki,Chai, Jangbom 한국압력기기공학회 2017 한국압력기기공학회 논문집 Vol.13 No.1

We diagnosed the defect using the data obtained from the nuclear power plant simulator. In this paper, we diagnosed faults in the nuclear power plant system for discovery instead of the traditional single-component or device unit. We created the six fault scenarios and used a fault simulator to obtain the fault data. It was extracted pattern from acquired failure data. Neural network model was trained and simple pattern matching algorithm was applied. We presented a simulation result and confirmed that the applied algorithm works correctly.

일기(日記) 자료를 통해 본 16세기 후반 수령(守令)의 관외(管外) 활동 -강화도호부사(江華都護府使) 전순필(全舜弼)의 사례 연구-

안홍민 인하대학교 한국학연구소 2010 한국학연구 Vol.0 No.23

조선시대 수령의 주된 근무장소는 관아를 중심으로 한 자신의 관할 군현 내였고 자신의 일상생활의 장소도 관내였다. 그러나 수령은 여러 가지 공, 사적인 이유로 인해 관외로 출타하는 경우가 많았다. 그 중에서도 공적인 이유에서의 관외 업무는 조선시대 수령 업무의 중요한 부분으로, 본 연구에서는 수령의 관외 업무에 대해 집중하여 다루었다. 16세기 후반 江華都護府使를 지낸 全舜弼의 『先祖 江華先生日記』에는 부사 재임 중 총 28차례 강화 섬 밖으로 출타한 사례가 드러난다. 이 중에는 사적인 이유에서의 출타도 있었지만 대부분은 산릉에서의 제관 업무, 왕의 親祭나 仁順王后의 國葬과 관련하여 능행의 길목에 있는 松溪橋梁의 보수 등 공적인 목적에서 이루어졌다. 이러한 업무는 전순필에게 있어서 중요한 업무였을 뿐 아니라 경기지역의 지방관과 開城府, 中央 官府의 官吏 등이 동원되는 업무이기도 했다. 또한 전순필은 수령의 일상적인 기타 관외 업무도 수행하였다. 이러한 업무 분석을 통하여 타도에 비하여 都城 인근에서 근무하는 경기지역의 수령에게 가중되는 업무적 부담이 있었음이 파악되었다. 또한 수령의 1차적 책임 단위는 관할 군현이지만 도 전체적인 광역화된 업무 수행도 중요했음을 알 수 있었다. Generally speaking, it was within their jurisdiction, especially around their office, that county magistrates worked and leaded their everyday life during the Joseon Dynasty. Nevertheless, they often went outside the jurisdiction for various reasons, either public or private. The author focuses on their public outside-the-jurisdiction business which was an important part of their work. Jeon Soon-Pil(전순필)’s diary(Seonjo Ganghwa Seonsaeng Ilgi) says he went outside his jurisdiction 28 times during his reign as county magistrate of Ganghwa County in the late 16th Century. Sometimes he did for private reasons, but most of his trips were public ones such as presiding over worship ceremonies or repairing Songgye Bridge for the royal visits, which was very important for other county magistrates of Gyeonggido(경기도), those of Gaeseong County(개성부), even the central dignitaries as well as for him. Besides, he had some ordinary outside-the-jurisdiction work to do. Jeon Soon-Pil’s diary let us know that county magistrates of Gyeonggido had extra work and that they were responsible not only for their own county but also Do, the bigger district.

음향 매질의 추가질량 효과를 고려한 광음향 영상용 초소형 압전 기반 초음파 트랜스듀서의 개발

안홍민 ( Hongmin Ahn ),문원규 ( Wonkyu Moon ) 한국센서학회 2020 센서학회지 Vol.29 No.1

Typically, photoacoustic images are obtained in water or gelatin because the impedance of these mediums is similar to that of the human body. However, these acoustic mediums can have an additional mass effect that changes the resonance frequency of the transducer. The acoustic radiation impedance in air is negligible because it is very small compared to that of the transducer. However, the high acoustic impedance of mediums such as the human body and water is quite large compared to that of air, making it difficult to ignore. Specifically, in a case where the equivalent mass is very small, such as with a micro-machined ultrasound transducer, the additional mass effects of the acoustic medium should be considered for an accurate resonance frequency design. In this study, a piezoelectric micro-machined ultrasonic transducer (pMUT) was designed to have a resonance frequency of 10 MHz in the acoustic medium of water, which has similar impedance as the human body. At that time, the resonance frequency of the pMUT in air was calculated at 15.2 MHz. When measuring the center displacement of the manufactured pMUT using a laser vibrometer, the resonance frequencies were measured as 14.3- 15.1 MHz, which is consistent with the finite element method (FEM) simulation results. Finally, photoacoustic images of human hair samples were successfully obtained using the fabricated pMUT.

An Expected Crisis : A Case Study of Volkswagen Diesel Crisis

이상열,안홍민,조용석 한국광고PR실학회 2017 광고PR실학연구 Vol.10 No.1

This exploratory case study analyzes the Volkswagen diesel crisis from a crisis communication perspective. The Volkswagen diesel case provides a unique opportunity to examine how a Fortune 500 company managed (or mismanaged) an intentional corporate misdeed, and to understand the shortcomings of existing crisis communication theories. In analyzing the case, this study adopted the theoretical frameworks from the two dominant crisis communication theories, namely Image Repair Theory and Situational Crisis Communication Theory. Our findings show Volkswagen’s systemic failure of crisis management and communication before and after the crisis erupted. The findings also suggest the scholarly need to further develop crisis communication theories in providing strategic implications for major crises such as the Volkswagen diesel case.

틱톡 인피드 광고태도 연구: 기술수용모델과 지각된 침입성, 이용자 몰입을 중심으로

서아려,안홍민 계명대학교 사회과학연구소 2022 한국사회과학연구 Vol.41 No.3

This study examined the factors affecting the effectiveness of TikTok in-feed advertisements. Specifically, the purpose of the study was to examine how the TikTok user acceptance (perceived usefulness, perceived ease of use, perceived enjoyment) and perceived intrusiveness would affect the attitudes toward the in-feed ad. In addition, the mediating effect of flow was examined by analyzing the role of user flow as a parameter linking antecedent and outcome variables. The results of an online survey with 354 participants showed that perceived usefulness and perceived playfulness had a significant positive (+) effect on attitudes toward the ad, and perceived intrusiveness, which is negative perception of in-feed advertising, had a negative (-) effect on advertisement attitude. In the results of examining the mediating effect of user flow, it was found that user flow mediates the effect of perceived usefulness and perceived playfulness on the TikTok in-feed advertising attitudes. The results of this study will contribute to the academic development of research on TikTok and in-feed advertisements, and provide practical help to companies in establishing marketing strategies and advertisement strategies using TikTok.

상문화(丧文化) 유머광고 효과 연구: 소비자 스트레스와 마인드셋 유형 효과를 중심으로

유초붕,안홍민 동국대학교 사회과학연구원 2019 사회과학연구 Vol.26 No.4

When the society develops at a high speed, it will usher in a period of stability, and at this time, a series of problems caused by the rapid development of society will be exposed. In order to alleviate the social contradictions of various exposures, the ‘Sang marketing’ appears in China. Sang marketing is an emotional marketing based on sang culture. It has the effects of releasing pressure between generations, forming a psychological defense and constructing a group identity. This study attempts to conceptualize the concept of sang marketing through literature and identify factors influencing ad manifested sang culture. To this end, a 2 (stress: high vs. low) x 2 (mindset: growth vs. fixed) between subjects was conducted. Results showed that consumers with high-stress (vs. low-stress) had positive responses to the ad (i.e., humor perception, advertising comprehension, attitudes toward the ad, and purchase intention). In addition, consumers with fixed mindset (vs. growth mindset) had positive responses to the ad. Interestingly, there was an interaction effect between stress and consumer mindsets. 최근 중국에서는 한국의 ‘N포 세대’ 정서와 비슷한 상문화(丧文化)라는 개념이 등장하고 이에 기반을 둔 상마케팅이 주목을 받고 있다. 상마케팅 콘텐츠 소비를 통해 사람들은 무한경쟁에 대한 스트레스를 해소하고, 성공하지 못한 개인에게 심리적인 방어기제를 형성하며, 더 나아가 집단 정체성을 구축하는 효과가 있다고 알려져 있다. 그러나 이러한 감성마케팅의 빠른전염에 비해 용어에 대한 개념 정의 및 그 효용에 대한 학술적 논문은 전무하다. 따라서 본 논문을 통해 상마케팅이란 과연 무엇이며 상마케팅 효과에 영향을 주는 요소는 어떠한 것들이 있는지 학술적으로 고찰해 보고자 한다. 특히 상마케팅에는 자기비판적 유머 형태가 주로 쓰이는데, 이에 본 연구는 이러한 유머 형태에 영향을 미치는 요소로 소비자 스트레스 정도, 마인드셋유형 (고정형 마인드셋, 성장형 마인드셋)이 광고의 정서적, 행동적 반응(유머 감지도, 광고 이해도, 광고 태도 및 구매의도)에 어떠한 효과를 미치는지를 실증적으로 탐색하였다. 실험 결과고 스트레스 집단은 저 스트레스 집단 보다 높은 상문화 마케팅 광고 수용도를 보였으며, 고정형 마인드셋 소비자 집단은 성장형 마인드셋 집단보다 상문화 마케팅 광고에 더 긍정적인 태도를 보였다. 또한 스트레스 지수의 주 효과는 고정형 마인드셋 집단에서 더욱더 크게 나타나 두변인 간의 상호작용이 존재하는 것으로 밝혀졌다. 본 논문의 연구 결과를 통해 상마케팅에 대한 이해가 넓어질 수 있는 계기가 되기를 바라며, 이에 대한 지속적인 관심과 후속 연구를 기대한다.