Minimally Invasive Lumbar Spinal Decompression in Elderly Patients with Magnetic Resonance Imaging Morphological Analysis

하승만,홍영호,이승철 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: Case-control study. Purpose: In this study, we aimed to investigate clinical outcomes and morphological features in elderly patients with lumbar spinal stenosis (LSS) who were treated by minimally invasive surgery (MIS) unilateral laminectomy for bilateral decompression (ULBD) using a tubular retractor. Overview of Literature: Numerous methods using imaging have been attempted to describe the severity of spinal stenosis. But the relationship between clinical symptoms and radiological features remains debatable. Objective: In this study, we aimed to investigate clinical outcomes and morphological features in elderly patients with LSS who were treated by MIS-ULBD Methods: We methodically assessed 85 consecutive patients aged >65 years who were treated for LSS. The patients were retrospectively analyzed in two age groups: 66–75 years (group 1) and >75 years (group 2). Clinical outcomes were assessed using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the modified MacNab criteria. Outcome parameters were compared between the groups at the 1-year follow-up. Core radiologic parameters for central and lateral stenosis were analyzed and clinical findings of the groups were compared. Results: At the 1-year follow-up, patients in both groups 1 and 2 demonstrated significant improvement in their VAS and ODI scores. All clinical outcomes, except postoperative ODI, were not significantly difference between the groups. In addition, no significant difference was noted in the preoperative radiological parameters between the groups. There was no statistically significant correlation between radiological parameters and clinical symptoms or their outcomes. Moreover, no differences were noted in perioperative adverse events and in the need for repeat surgery at follow-ups between the groups. Conclusions: MIS-ULBD by tubular approach is a safe and effective treatment option for elderly patients with LSS. Clinical outcomes in patients with LSS and aged >75 years were comparable with those in patients with LSS and aged 66–75 years. Moreover, we did not find any correlation between radiological parameters and clinical outcomes in either of the two patient groups.

Intradural Extramedullary Ependymoma with Spinal Root Attachment: A Case Report

하승만,신동아 대한척추신경외과학회 2012 Neurospine Vol.9 No.3

A 36-year-old female patient presented with shoulder pain experienced over a period of one year and progressive weakness in both legs for one month. A magnetic resonance imaging scan revealed an intradural extramedullary (IDEM) fusiform mass about 9.8 cm in length, heterogeneously enhanced at the level of C6-T4 with spinal cord compression. At the time of surgery,the surgeon found an encapsulated IDEM tumor with spinal root attachment. The tumor was completely resected and the histologic diagnosis revealed ependymoma. The patient showed a favorable outcome with no recurrence at the 6-month follow-up. This paper reports a rare case of intradural extramedullary ependymoma with spinal root attachment.

반응표면분석법을 이용한 제올라이트의 다중 중금속 흡착인자 최적화

하승한(Seunghan Ha),송진수(Jinsu Song),안종화(Johnghwa Ahn) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11

간 수술의 병력이 없는 환자에서 발생한 담관 원주 증후군

하승인 ( Seung In Ha ),최정식 ( Jung Sik Choi ),김영훈 ( Young Hoon Kim ),전현수 ( Hyun Soo Jun ),조용건 ( Yong Gun Jo ),이원현 ( Won Hyun Lee ),박성길 ( Seong Gill Park ),이상헌 ( Sang Heon Lee ) 대한소화기학회 2012 대한소화기학회지 Vol.60 No.6

Biliary cast describes the presence of casts within the biliary tree. It is resultant sequel of cholangitis and hepatocyte damage secondary to bile stasis and bile duct injury. Biliary cast syndrome was first reported in patient undergone liver transplantation. The pathogenesis of biliary cast is not clearly identified, but proposed etiologic factors include post-transplant bile duct damage, ischemia, biliary infection, or post-operative biliary drainage tube, Although biliary casts are uncommon, most of biliary cast syndrome are reported in the liver transplant or hepatic surgery patients. A few reports have been published about non-transplant or non-liver surgery biliary cast. We report two cases of biliary cast syndrome in non-liver surgery patients.

내시경적 역행성 담관조영술 중에 발생한 식도천공에 의한 기흉 1예

하승인,김신,김유리,박찬복,이지현,윤병철,한병훈,이상욱,신동훈 고신대학교 의학부 2004 高神大學校 醫學部 論文集 Vol.19 No.1

Esophageal perforation is an extremely lethal injury that requires careful management for survival. Currently, the most common cause of the perforation is iatrogenic injury, and the incidence of esophageal perforation has increased as the use of endoscopic procedure has become more frequent. Perforation during endoscopic retrograde cholangiogram (ERC) are rare. Bile duct or duodenal perforation caused by therapeutic procedures such as endoscopic sphincterotomy, guide-wire, and biliary stent were frequently reported. However, the case of esophageal perforation developed during diagnostic ERC was very rare and there has not report in Korea yet. A 61-year-old man was admitted for the evaluation of upper abdominal pain. He suspected bile duct dilatation and common bile duct stone by ultrasongraphy. During the diagnostic ERC, endoscopy showed structure of pleural cavity. We suspected esophageal perforation, and then checked esophagogram, neck and chest CT. The CT showed right side pneumothorax and left parapharyngeal and retropharyngeal air shadow. We diagnosed esophageal perforation accompanied with pneumothorax. He was successfully treated with medical treatment for 10 days.

청능재활을 위한 AI 기반 음성신호의 특징 추출 및 분석

하승한,이상도 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.5

The purpose of this study was to extract and analyze features of speech signals using artificial intelligence techniques, with the goal of improving auditory rehabilitation outcomes. Wav2vec 2.0 was used to identify phonemes in 2,000 sound files recorded from individuals with hearing impairment. The average speech intelligibility score was calculated to be over 0.92 %, determined by calculating the difference between a reference sentence and the sentence obtained through speech-to-text (STT). It was possible to distinguish individual phonemes accurately from recorded sound files of speech produced by individuals with hearing impairments, and to measure the intelligibility of their speech by assessing their speech clarity. Through this experiment, we confirmed the potential to distinguish phonemes between individuals with normal hearing and those with hearing impairment, as long as the phonemes are similar to the reference sentence for individuals with normal hearing. Furthermore, it was confirmed that it is possible to differentiate the accuracy of pronunciation in speech produced by individuals with hearing impairments, which further supports the potential for assessing speech intelligibility in this population through phonetic analysis. To validate the effectiveness of artificial intelligence-based speech signal feature extraction and analysis for auditory rehabilitation, a comparative study on phoneme extraction between individuals with normal hearing and those with hearing impairment should be conducted. 이 연구의 목적은 청능재활을 향상시키기 위해 인공지능 기술을 활용하여 음성 신호의 특징을 추출하고 분석하는 것이다. Wav2vec 2.0을 이용하여 청각장애인 2,000명으로부터 얻은 소리 파일에서 음소를 추출하고 말 명료도를 측정하였다. STT(Speech to Text)로 얻은 문장과 스크립트로 작성된 기준 문장의 차이를 말 명료도로 설정하였으며, 이를 기준으로 계산한 결과 평균 말 명료도 점수는 0.92% 이상이었다. 청각장애인의 발화를 통해 녹음된 소리 파일에서 음소를 정확히 구별할 수 있었으며, 청각장애인의 발화를 통해 녹음된 발음의 정확성을 확인하기 위해 말 명료도를 측정할 수 있었다. 이 실험을 통해, 비장애인의 음소가 기준 문장과 유사하다면 비장애인과 청각장애인 사이에서 음소를 구별할 수 있다는 가능성을 확인하였다. 또한, 청각장애인의 발화에서 발음의 정확성을 구분할 수 있는 가능성도 확인하다. 앞으로 청능재활을 위한 인공지능 기반의 음성 신호 특징 추출 및 분석의 유효성 검증을 위해 비장애인과 청각장애인을 대상으로 음소 추출 비교 연구가 진행되어야 한다.

초임계 이산화탄소를 이용한 폐 페인트 슬러지 처리

하승일(Seungil Ha),박광헌(Kwangheon Park),최창식(Changsik Choi),신재빈(Jaebin Shin),손효경(Hyokyung Son) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

Squalene 복용 후 발생한 지방성 폐렴 1례

하승인,이시원,김주훈,양성우,옥철호,장태원,정만홍 대한결핵 및 호흡기학회 2003 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.97 No.0

에탄올이 초임계 이산화탄소를 이용한 폐 페인트 슬러지 처리에 미치는 영향 연구

하승일,박광헌,최창식,신재빈,손효경 한국대기환경학회 2021 한국대기환경학회 학술대회논문집 Vol.2021 No.10

자동차 제조 공정 중 도장공정 내 CWS (circulating water system)에서 수거되는 페인트 슬러지는 폐기물처리 시 많은 비용이 발생한다. 따라서 페인트 슬러지의 부피를 감량하여 처리 비용을 감축할 수 있는 추가적인 처리 공정이 요구된다. 따라서 본 연구에서는 2차 폐기물 발생을 줄일 수 있는 친환경적인 용매로써 초임계 이산화탄소를 이용한 페인트 슬러지 처리실험을 진행하였다. 이산화탄소는 무독성이며 물질에 대한 침투성이 좋아 높은 처리효율을 기대할 수 있으며, 이산화탄소와 같이 상온에서 기체인 유체는 공정 후 감압을 통하여 폐기물과 분리시켜 2차 폐기물 발생문제를 해결할 수 있다. 또한 분리된 이산화탄소를 재사용할 수 있으므로 공정비용 감소 효과도 기대할 수 있다. 본 연구에서는 초임계 이산화탄소를 이용한 처리공정을 통해 페인트 슬러지의 함수율 감소량과 유기물 제거 가능성을 실험하고, 에탄올의 첨가여부에 따른 처리효율 차이를 확인하였다. 실험에 쓰인 샘플은 자동차 제조업체에서 사용되는 페인트 슬러지를 사용하였으며, 페인트 슬러지의 성분 비율에 따라 클리어/ 상도베이스1 / 상도베이스2 총 3종류로 구분하였다. 실험 조건의 경우 샘플 질량을 5 g으로 통일하였고, 샘플이 담긴 반응용기에 이산화탄소를 주입하여 온도 40℃ 조건에서 200 bar로 가압하였다. 이후 평균 3.5mL/min의 유량으로 2시간 동안 이산화탄소를 흘림으로써 실험을 마무리하였다. 추가적으로 실험 조건에 에탄올을 첨가함으로써 에탄올이 처리 효율에 미치는 영향을 확인하였다. 실험 결과 유기물량에 비해 함수율의 감소 효과가 뚜렷하게 나타났으며, 에탄올의 첨가로 인한 수분 추출의 가속화를 확인하였다. 이를 통해 향후 공정 확대가 이루어진다면 이산화탄소 용매 재사용으로 인한 처리 비용 감소와 함께 효율 증대가 이루어질 것으로 기대된다.

기계 학습에 기초한 추천시스템 알고리즘에 대한 연구

하승인(Ha, SeungYin),유영범(Yoo, Yiung Bum),정예숙(Jung, Ye Suk) 한국서비스경영학회 2017 한국서비스경영학회 학술대회 Vol.2017 No.11

Online content service providers are using recommendation systems as part of their efforts to increase sales. The recommendation system identifies and recommends the customer "s preferred content, and it helps the customer to increase the satisfaction and the loyalty of the service by using the content suitable for the user" s taste without searching the content. In this study, we propose an algorithm for selecting recommendation contents for individual customers by using the Movie Lens data. The algorithms used in the existing recommendation systems have the disadvantage that they can not utilize contents that do not exist in the data since the important words are selected from the given data and the contents are selected based thereon. On the other hand, the Latent Dirichlet Allocation algorithm is that can utilize potential keywords that are not in the data.