수질정화용 블록을 적용한 하도내 수질개선 효과

원희재(Won, Hee Jae),서대석(Seo, Dae Sok),김봉균(Kim, Bong Kyun),박준석(Park, Jun Seok) 한국콘크리트학회 2017 한국콘크리트학회 학술대회 논문집 Vol.29 No.1

광촉매와 미생물을 이용한 다공성 콘크리트의 비연속 흐름실험을 통한 수질정화 효과 검토

원희재(Won, Hee Jae),신성진(Shin, Sung Jin),김화중(Kim, Wha Jung) 한국콘크리트학회 2015 한국콘크리트학회 학술대회 논문집 Vol.2015 No.10

고관절 수술에서 3D 프린팅의 응용: 현재 그리고 미래

원희재(Heejae Won),백승훈(Seung-Hoon Baek),김신윤(Shin-Yoon Kim) 대한정형외과학회 2022 대한정형외과학회지 Vol.57 No.1

고관절과 골반은 해부학적 특성으로 인해 3D 프린팅(three-dimensional printing) 기술이 활발하게 임상에 도입되고 있다. 현재 고관절 수술에서 사용되는 3D 프린팅 기술은 수술 전 계획이나 모의 수술을 위한 골 모형, 환자 맞춤형 수술기구(patientspecific instrument), 삽입물의 안정적인 고정을 위한 표면 처리(surface treatment), 환자의 해부학적 특성에 맞는 맞춤형 삽입물(customized implant)의 4가지 형태로 활용되고 있다. 정형외과 의사는 3D 프린팅 기술을 통해 수술법을 개선하고, 수술 중 발생 가능한 합병증을 최소화하며, 환자에게 좀더 적합한 삽입물을 정확한 위치에 고정할 수 있다. 근래에는 3D 프린팅을 위한 새로운 재료들이 탐색되고 있으며, 출력물의 제작 과정 개선을 통한 비용 및 제작 시간의 효율성이 향상되고 있다. 또한 표면 처리를 개선하여 지속적으로 약물을 전달하거나, 증강현실 등 다른 신기술과의 융합도 시도되고 있으며, 3D 생체 프린팅 기술을 이용한 조직이나 기관의 재생 역시 활발하게 연구되고 있다. 무엇보다도 정형외과 의사는 기존의 치료 방법만 고수할 것이 아니라 이러한 새로운 경향들을 익히고 연구함으로써 환자들에게 최선의 치료법을 제공할 수 있도록 노력해야 할 것이다. Three-dimensional (3D) printing is increasing gradually in orthopedic surgery. Currently, the use of 3D printing in hip surgery is as follows: a bone model for preoperative planning or simulation, patient-specific instruments, surface treatment for stable fixation of implant, and customized implants tailored to the patient’s anatomical characteristics. Orthopedic surgeons can utilize 3D printing technology to improve the surgical techniques, minimize complications during surgery, and provide implants that are more suitable for patients in the correct position. In recent years, new materials for 3D printing are being explored, and the efficiency of cost and production time is improved by developing the production process. In addition, constant drug delivery by improving surface treatment, fusion with other new technologies, such as augmented reality, and tissue or organ regeneration using 3D bioprinting technology is being actively conducted. Above all, orthopedic surgeons should strive to provide the best treatment to patients by learning and researching these new trends, not just adhering to existing treatment methods.

P2P 환경에서 협업 필터링을 이용한 음악 추천 시스템에 대한 연구

원희재(Hee-Jae Won),박규식(Kyu-Sik Park) 한국멀티미디어학회 2008 멀티미디어학회논문지 Vol.11 No.10

적층 방향에 따른 3D 프린팅 콘크리트의 강도 특성

원희재(Hee-Jae Won) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.2

현재 미래의 건설 산업 기술을 발전시키고자 최근 미래 산업으로 각광받고있는 3D 프린팅을 이용한 콘크리트의 시공기술을 활용하여 구조물을 건설하는 연구가 국내외 건설업계 및 학계에서 활발히 진행되고 있다. 하지만 현재 개발되고 있는 3D 프린팅 기술은 적합한 시공기술, 콘크리트 재료 자체의 물성이 사용기준에 미치지 못하고 실제 현장에서 적용하기가 어려운 상황이다. 또한 시공된 구조물에 대한 내구성 관리 및 유지관리를 위한 연구가 필요한 실정이다. 본 연구에서는 Material extrusion 방식으로 출력한 3D 프린팅 콘크리트를 각각의 적층 방향 X, Y, Z축으로 나누어 측정한 압축강도와 휨강도를 기존의 몰드에 제작한 시험체와 비교 분석하였다. Test direction Ⅱ Z축의 시험체의 압축강도가 나머지 Test direction Ⅰ,Ⅲ Y축, X축의 시험체에 비하여 8~10%의 높은 강도를 발현하였고 몰드 제작 시험체와 비교하였을 경우 4%가량 낮은 강도를 발현하였다. 휨강도 측정결과 재령 28일 기준으로 Test direction Ⅱ Z축 방향의 시험체의 휨강도가 Test direction Ⅰ,Ⅲ Y축, X축의 시험체에 비하여 5~7%의 높은 강도를 발현하였고 몰드 제작 시험체와 비교하였을 경우 2%가량 낮은 강도를 나타내었다. In order to develop future construction technology, research is actively being conducted on concrete construction technology using 3D printing, which is currently in the spotlight as a future industry in domestic and foreign construction industries and academia. However, 3D printing technology is currently being developed and does not meet the requirements for proper construction technology and the properties of concrete materials, and it is difficult to apply in the actual field. Research is also needed for the durability management and maintenance of constructed structures. This work compares the compressive and flexural strength to that produced in conventional molds by dividing the 3D printed concrete output by the laminated X, Y, and Z axes. The compressive strength of a test specimen in the II Z-axis test direction was 8-10% higher than that of the other test directions (I and III Y axes and X axis). The strength was 4% lower than that of a molded test specimen. As of 28th of the age, the bending strength of the test specimen in the Z-axis direction was 5 to 7% higher than that of the I and III Y, and X-axis test directions, and the strength was 2% lower than that of the molded test specimen.

ortho-Benzoquinone을 기반으로 하는 청색광 차단 수화젤 콘택트렌즈 제조

원희재(Hee Jae Won),김병선(Byung Sun Kim),조병기(Byoung-Ki Cho) 한국고분자학회 2020 폴리머 Vol.44 No.6

Catechol 단량체를 dopamine과 methacrylic anhydride와의 반응을 통해 합성하였다. 이후, 2-hydroxy ethylmethacrylate(HEMA), ethylene glycol dimethacrylate(EGDMA), 2-methacryloyloxyethyl phosphorylcholine (MPC)과 공중합한 후, 염기 조건에서 산화반응을 수행하여 ortho-benzoquinone을 기반으로 하는 갈색 투명한 청색광 차단 수화젤 렌즈를 제조하였다. 제조 시, catechol 단량체의 첨가량에 따라, 청색광 차단 정도를 조절할 수 있었으며, 최대 38%까지 청색광을 차단하였다. 또한 UV-A 및 UV-B 영역도 차단하는 효과를 보였다. 제조된 렌즈들은 87% 이상의 평균 가시광선 투과율을 보였다. 함수율과 접촉각은 각각 60% 이상, 60° 미만의 수치를 나타내어, 렌즈 내부 및 표면에서의 친수성이 우수하다는 것을 알 수 있었다. Catechol monomer was synthesized by the reaction of dopamine and methacrylic anhydride. Then, it was copolymerized with 2-hydroxy ethylmethacrylate (HEMA), ethylene glycol dimethacrylate (EGDMA), 2-methacryloyloxyethyl phosphorylcholine (MPC). Subsequent oxidation reaction under a basic condition produced transparent and brownish blue-light blocking hydrogel contact lenses (BB Lenses) based on ortho-benzoquinone. Degree of the blue-light blocking could be controlled depending on the amount of catechol monomer at the initial mixing step of monomers. The maximum blue light blocking ratio was determined to be 38%, and the BB lenses also blocked UV-A and UV-B. The BB lenses exhibited high luminous transmittances more than 87%. The water content and contact angle values were more than 60% and less than 60°, respectively, indicating excellent hydrophilicity both interior and surface of lenses.

포러스콘크리트의 설계공극률 및 부석 혼입률에 따른 수계환경 적용 가능성 평가

원희재(Won, Hee Jae),서대석(Seo, Dae Sok),김봉균(Kim, Bong Kyun) 한국콘크리트학회 2017 한국콘크리트학회 학술대회 논문집 Vol.29 No.2

지역약국 약사에 의한 약물관련문제 중재 현황

송문영,원희재,김시형,이종우,오푸름,이형우,김혜린 한국보건사회약료경영학회 2020 한국보건사회약료경영학회지 Vol.8 No.2

BACKGROUNDS Community pharmacists contribute to safe and effective drug treatment for patients by per-forming various prescription interventions through simultaneous drug utilization review (DUR) and checking patient medi-cation history. Our study aimed to analyze the interventions on drug-related problems (DRPs) by pharmacist from a community pharmacy. METHODS We obtained data for DRPs and the interventions by pharmacist which was recorded between 2019.7.22 and 2019.8.30 in working hours on weekdays at a community pharmacy located in Nowon-gu. Data was collected using a well-developed form ("Pharmacist Intervention on DRPs"). Data contained patient related factors, charac-teristics of prescription issuing institutions, DRPs, pharmacist interventions, intervention acceptance, and time required for intervention recording. RESULTS Pharmacist' intervention occurred 47 cases (1.04%) among the total 3,831 prescriptions during the study period. Men and women were 50% each, and the average age was 58.3 (±20.6, SD) years. The most com-mon types of DRPs were 'duplication (same drug)' of 53.2% (25 cases), and as for the pharmacist intervention, 'discon-tinue medication' was done most frequently as 48.9% (23 cases). In the drug efficacy groups, the musculoskeletal drugs were the most common with 33.3% (16 cases), followed by the alimentary tract and metabolism drugs with 16.7% (8 cases). The average time spent on intervention recording was 4.1 minutes (±4.0). CONCLUSION The current status of DRP and pharmacist interventions was identified through data from one community pharmacy collected through a system-atic record format. Intervention by community pharmacists plays an important role in the safe and effective utilization of treatment.

Preoperative Iron Supplementation and Restrictive Transfusion Strategy in Hip Fracture Surgery

윤병호,이범석,원희재,김형국,이영균,구경회 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.3

Background: Hip fracture surgery (HFS) is often associated with perioperative blood loss, and it frequently necessitates transfusion. However, the hemoglobin (Hb) threshold for transfusion remains controversial in hip fracture patients. We evaluated the usefulness of the restrictive strategy and preoperative intravenous iron supplementation in HFS. Methods: We retrospectively reviewed the medical records of 1,634 patients (> 60 years of age) who underwent HFS between May 2003 and June 2014 and were followed up for 1 year or more after surgery. We used the liberal transfusion strategy until May 2009 to determine the transfusion threshold; afterwards, we switched to the restrictive transfusion strategy. Patients with the restrictive transfusion strategy (restrictive group) received intravenous iron supplementation before surgery. We compared the transfusion rate, morbidity, and mortality of the restrictive group with those of the patients with the liberal transfusion strategy (liberal group). Results: Preoperative intravenous iron supplementation was not associated with any adverse reactions. The transfusion rate was 65.3% (506/775) in the liberal group and 48.2% (414/859) in the restrictive group (p < 0.001). The mean hospital stay was shorter in the restrictive group (21.5 vs. 28.8 days, p < 0.001). There was no significant difference in the postoperative medical complications including myocardial infarction and cerebrovascular event. Mortality at postoperative 30, 60, and 90 days was similar between the two groups. Conclusions: Our blood management protocol involving restrictive strategy combined with preoperative intravenous iron supplementation appears to be effective and safe in HFS of elderly patients.

고관절 및 인공 고관절의 생역학

이영균,최지혜,원희재,구경회 대한정형외과학회 2019 대한정형외과학회지 Vol.54 No.5

The biomechanics study of the hip is aims to understand and explore the dynamic principles of weight transfer through the hip joint. This basic science knowledge can be applied in a variety of areas, including degenerative joint diseases and hip replacement arthroplasty. In particular, understanding of the biomechanics of the hip has led to the development of materials, design and fixation of implants, and it can be applied in various areas, such as the selection of surgical methods and the location of the implant. Moreover, it is essential to have good knowledge of the biomechanics of the hip to achieve better clinical results for patients. Therefore, this paper introduces the basic knowledge and biomechanical characteristics of a normal hip and hip replacement arthroplasty, which are needed to approach the biomechanics of the hip. 고관절의 생역학은 고관절에서 체중이 관절면을 통해 전달되는 역학적인 원리를 이해하고 탐구하는 학문이다. 이러한 기초 과학 지식은 퇴행성 관절의 병리와 고관절 치환술 등 다양한 분야에 적용될 수 있다. 특히 고관절의 생역학에 대한 이해를 통해 인공 고관절 치환물의 재료와 설계 및 고정과 관련된 고관절 치환술 분야의 발전을 이루어 왔으며, 수술 방법의 선택, 치환물의 선택 및 위치 등 다양한 부분에 적용될 수 있다. 더욱이 환자의 보다 나은 임상 결과를 얻기 위해서는 고관절의 생역학을 잘 이해하는 것이 필수적이다. 따라서 여기서는 고관절의 생역학을 접근하는 데 필요한 기본적인 지식과 정상 고관절 및 인공 고관절의 생역학적 특성을 알아보고자 한다.