LCC분석에 의한 슬러지수집기 선정 모델

이승훈,우유미,이성락,구교진,현창택,홍태훈,Lee, Seung-Hoon,Woo, Yu-Mi,Lee, Sung-Rak,Koo, Kyo-Jin,Hyun, Chang-Taek,Hong, Tae-Hoon 한국건설관리학회 2006 건설관리 : 한국건설관리학회 학회지 Vol.7 No.6

사회기반시설의 노후화에 따라 시설물 유지관리에 관한 관심이 증대되고 있으며, 이에 따라 다양한 사회기반시설에 대한 LCC분석 연구가 수행되고 있다. 특히 기계설비가 다수 포함된 기반시설에서는 시설물의 건설비와 더불어 보수/교체비, 에너지비 등 유지관리비용이 높은 비중을 차지하고 있다. 이에 본 연구에서는 하수처리장의 슬러지 수집기 선정에 있어 정량적 요소와 정성적 요소를 모두 고려하는 LCC 분석 모델을 개발하고, 사례적용을 통하여 최적대안을 선정하고자 한다. 문헌고찰과 분석대상 하수처리장의 슬러지 수집기에 대한 공사비와 유지관리 및 보수/교체 이력자료를 바탕으로 비용항목을 도출한다. LCC분석을 위한 가정사항 설정 후, 각 항목별 실적자료와 장비납품업체의 정보를 활용하여 경제성 평가결과를 도출하고, 할인율과 초기투자비 및 유지관리비의 비용변동범위에 따른 민감도분석을 실시한다. 설계자, 자재공급업체 및 시공전문가의 면담을 통하여 유지관리 편의성, 조달 용이성, 슬러지 수집 성능, 침전물제거 효율도, 환경친화성 등 슬러지 수집기 선정을 위한 기술적 사회적 영향인자를 파악한다. 분석된 기술적 사회적 요인과 LCC 분석결과인 경제성에 대하여 각 항목별 쌍별비교를 통하여 항목별 가중치를 설정하고 전문가 평가를 통하여 종합적인 최적안을 선정한다. This study focused on developing Life Cycle Cost(LCC) analysis model for selecting sludge collectors in wastewater treatment system and applying the model to a case study. Cost items are examined through literature review and historical data of a facility. Analysis period, discount rate, energy cost escalation ratio are assumed to reasonable level. Monetary evaluation is performed using historical data and estimations from vendors. Sensitive analysis is executed using Monte Carlo Simulation for assumed factors. Interviews with operators, vendors, constructors, managers are conducted to define factors which indicates ease of maintenance, ease of delivery, technical performance, efficiency, environmental friendship. Factors are representing technical and social factors. Results from LCC analysis and qualitative analysis are evaluate together with Weighted Matrix Evaluation Methods for optimum alternative of sludge collectors.

주요우울장애의 치료로서 경두개 직류자극술(Transcranial Direct Current Stimulation)의 현재

이승훈,김용구,Lee, Seung-Hoon,Kim, Yong-Ku 대한생물정신의학회 2018 생물정신의학 Vol.25 No.4

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that delivers 1-2 mA of current to the scalp. Several clinical studies have been conducted to confirm the therapeutic effect of major depressive disorder (MDD) patients with tDCS. Some studies have shown tDCS's antidepressant effect, while the others showed conflicting results in antidepressant effects. Our aim of this review is to understand the biological bases of tDCS's antidepressant effect and review the results of studies on tDCS's antidepressant effect. For the review and search process of MDD treatment using tDCS, the US National Library of Medicine search engine PubMed was used. In this review, we discuss the biological mechanism of tDCS's antidepressant effect and the existing published literature including meta-analysis, systematic review, control trial, open studies, and case reports of antidepressant effects and cognitive function improvement in patients with MDD are reviewed. We also discuss the appropriate tDCS protocol for MDD patients, factors predictive of response to tDCS treatment, the disadvantages of tDCS in MDD treatment, and side effects.

가소제 함유 PVDF 나노섬유의 상용화 가능성에 관한 연구

이승훈,소윤미,장선호,심현주,김찬,Lee, Seung-Hoon,So, Yun-Mi,Jang, Seon-Ho,Shim, Hyun-Joo,Kim, Chan 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.4

The mechanical properties and softness of electrospun polyvinylidene fluoride (PVDF) nanofibers was improved by the addition of a small amount of tributyl citrate (TBC) plasticizer to PVDF spinning solutions. The PVDF nanofibers containing TBC were prepared by electrospinning and subsequent calendering. The morphology, mechanical properties, and thermal properties of the electrospun PVDF nanofibers were investigated using Field Emission Scanning Electron Microscopy (FE-SEM), tensile test and DSC analysis. The results of the tensile experiment indicate that the PVDF nanofibers containing 5 wt% of TBC have three times better strength and six times higher elongation in the mechanical direction (MD) compared to those of pure PVDF nanofibers. Thus, the results indicate that PVDF nanofibers containing TBC have potential applications not only in the textile industry but also in the electrical and biomedical fields. Further, the excellent mechanical properties and softness of the eco-friendly nanofibers containing TBC plasticizer is useful for its commercialization.

치아 기준의 악교정 수술용 석고모형 수술, 과연 가능하고 정확한가

이승훈,오성섭,이충국,박경란,이상휘,Lee, Seung-Hoon,Oh, Seong-Seob,Yi, Choong-Kook,Park, Kyung-Ran,Lee, Sang-Hwy 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.2

Purpose: Errors in orthognathic model surgery occur during the planning, measuring and/or moving of the models. However, there has been little effort to find ways to reduce these errors. In this study, we introduce a new orthognathic model surgery technique (Yonsei method) which adopts the tooth point as the reference and the occlusal index as a moving vehicle for the model. Methods: The technique consists mainly of: 1) measuring the three-dimensional lengths of model points, 2) fabricating and moving the occlusal index and 3) verifying the movement. Then we compared the accuracy of the Yonsei method to conventional methods, with special reference made to influencing factors. Results: Errors for the Yonsei method with the occlusal index were reduced to the range of 0.61~1.04 mm in three-dimension, providing a more accurate model surgery technique than conventional methods which have errors ranging from 0.77~3.11 mm. Conclusion: It provided us a more accurate model surgery technique based on the reference points onto the teeth and the use of occlusal index.

소아 폐쇄성 수면무호흡증후군 1례

이승훈,권순영,이상학,장지원,김진관,신철,Lee, Seung-Hoon,Kwon, Soon-Young,Lee, Sang-Hag,Chang, Ji-Won,Kim, Jin-Kwan,Shin, Chol 대한수면의학회 2004 수면·정신생리 Vol.11 No.1

페쇄성 수면무호흡증후군은 다양한 원인에 의하여 발생할 수 있으며, 특히 편도 및 아데노이드 비대증은 소아에서 가장 흔한 원인이다. 편도 및 아데노이드 비대증에 의하여 발생한 폐쇄성 수면무호흡증후군은 다양한 증상과 함께 행동 장애, 야뇨증, 성장 및 발달장애, 폐성심, 고혈압과 같은 다양한 합병증을 초래할 수 있다. 이러한 이유로 임상적으로 소아에서 폐쇄성 무호흡증상이 수면 중에 관찰되면 적절한 진단과정 후에 상태에 따라서 적극적인 치료가 필요하다. 소아에서의 치료는 편도 및 아데노이드 비대증에 의한 경우 수술적인 제거를 통하여 80% 이상에서 호전을 관찰할 수 있다. 그러나 편도 및 아데노이드 제거 후에도 증상이 남아있거나 수술적인 치료가 불가능한 환아에 대해서는 체중조절, 수면자세의 변화와 같은 생활습관의 조절 및 지속적 기도양압호흡기를 이용하여 추가적인 치료를 시행할 수 있다. 저자들은 수면다원검사상 심한 폐쇄성 수면무호흡이 관찰되어 편도 및 아데노이드 절제술을 시행한 후 증상의 호전이 있었으나, 장기간 추적관찰 후 재발한 수면무호흡과 코골이를 조절하기 위하여 생활습관의 개선교육과 자동화 기도양압호흡기로 치료한 1례를 경험하였기에 보고한다. The obstructive sleep apnea syndrome can occur due to various etiologies in children. In otherwise healthy children, adenotonsillar hypertrophy is the leading cause of childhood obstuctive sleep apnea. Obstructive sleep apnea caused by adenotonsillar hypertrophy can lead to a variety of symptoms and sequelae such as behavioral disturbance, enuresis, failure to thrive, developmental delay, cor pulmonale, and hypertension. So if obstructive sleep apnea is clinically suspected, proper treatment should be administered to the patient after diagnostic examinations. More than 80% improvement is seen in symptoms of obstructive sleep apnea caused by adenotonsillar hypertrophy in children after tonsillectomy and adenoidectomy. However, when it is impossible to treat the patient using surgical methods or residual symptoms remained after tonsillectomy and adenoidectomy, additional treatments such as weight control, sleep position change, and continuous positive airway pressure (CPAP), should be considered. This paper reports a case using weight control and Auto-PAP to control mild sleep apnea and snoring, which in long-term follow-up were not resolved after tonsillectomy and adenoidectomy for severe obstructive sleep apnea.

건설사업 설계초기단계 VE 적용방안

이승훈,구교진,현창택,Lee Seung-Hoon,Koo Kyo-Jin,Hyun Chang-Taek 한국건설관리학회 2005 건설관리 : 한국건설관리학회 학회지 Vol.6 No.3

본 연구는 설계초기단계에 적합한 VE 적용방안을 제안하고자 하였다. VE방법론은 설계단계 초기에 적용할 경우 더욱 효과적이므로 본 연구는 설계 프로세스 초기단계의 설계YE에 초점을 맞추고 있다. 관련 연구문헌의 고찰과 실무경험을 바탕으로 국내 건설산업에서 설계VE의 문제점을 도출하였다. 이러한 문제점을 해결하기 위하여 본 연구는 (1)설계단계별 VE실시시기를 구분하고, (2)건설산업에 적합한 VE대상선정 방법을 제안하며, (3)기능분석 프로세스를 보다 합리적이고 실용적으로 개선함으로써 (4)전체 설계VE 수행절차를 효율적으로 개선하고자 하였다. The purpose of this study is to present proper VE application methods to euly design phases. Since VE methodology is more effective on early stage of design phase, the study focused on application of VE methodology in early stage of design process. With the examination of past studies, obstacles of VE application in domestic construction industry are defined. To solve these problems, this paper presents (1) subdivision of VE execution time, (2) an appropriate VE targeting method for construction industry, (3) a resonable and practical function analysis process, and (4) modified design-VE job plan.

플라즈마 처리에 의한 폴리비닐리덴플로라이드 나노섬유의 젖음성

이승훈,장선호,소윤미,이헌수,양철민,윤중현,김찬,Lee, Seung-Hoon,Jang, Seon-Ho,So, Yun-Mi,Lee, Hun-Su,Yang, Cheol-Min,Yun, Jung-hyun,Kim, Chan 한국섬유공학회 2018 한국섬유공학회지 Vol.55 No.1

Poly(vinylidene fluoride) (PVDF) is a critical polymeric material used in the mass production and application of electrospun nanofibers, and is popular due to its excellent properties. However, electrospun PVDF nanofibers are very hydrophobic and possess low surface energies, limiting their broad application. In this work, we investigated practical methods for the hydrophobic surface modification of PVDF nanofibers using four techniques: radio-frequency (RF) and PIN-type atmospheric plasmas, planar inductively coupled plasma (ICP), and planar capacitively coupled plasma (CCP). The use of RF atmospheric plasma was ineffective under the experimental conditions used, while the PIN-type atmospheric plasma efficiently modified PVDF nanofiber surfaces locally. The application of planar CCP to PVDF nanofibers was more effective than planar ICP for the same experimental conditions. In particular, the water contact angles of samples treated with planar CCP for 600 s and 900 s were $25^{\circ}$ and $10^{\circ}$ respectively, and wettability improved. Analysis with FT-IR, XPS, and FE-SEM showed that the surface CF and CH hydrophobic groups were destroyed without damaging the PVDF nanofibers, and hydrophilic species such as C=O, OH, and COOH were formed. As a consequence, quantitative analysis of nanofiber chemical composition is necessary when treated by plasmas, providing insight into the correlation of specific property changes with processing conditions, and indicating precise research results and application examples.

이산화탄소 증가가 습지토양의 탈질세균 군집구조에 미치는 영향

이승훈,김선영,강호정,Lee Seung-Hoon,Kim Seonyoung,Kang Hojeong 한국미생물학회 2004 미생물학회지 Vol.40 No.3

이산화탄소 농도의 증가가 습지토양의 탈질세균 군집구조에 미치는 영향을 살펴보기 위하여 자연농도 (370 ppm)와 고농도 (740 ppm)의 이산화탄소조건의 습지생태계를 조성하여 110일 이상 배양한 후 토양 내 미생물 군집구조의 변화양상을 관찰하였다. 미생물 군집군조 분석은 탈질과정에 관여하는 효소중하나인 nitrite reductase의 유전자인 nirS 유전자를 대상으로 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) 분석기법을 이용하여 수행하였다. PCR 결과 모든 토양시료에서 nirS 유전자가 검출되었고, RFLP분석을 통해 자연농도의 이산화탄소조건에서 83개, 고농도 조건에서 95개의 phylotype을 획득하여 조성된 습지토양에서 탈질과정이 광범위하게 일어날 수 있음을 확인할 수 있었다. 두 경우 모두 두 종류 (type 1과 type 2)의 phylotype의 우점하고 있었고, 고농도 조건의 탈질세균 군집의 풍부도가 저농도 조건에 비해 더 높고, phylotype의 종류가 현저하게 변화되는 경향을 확인하였다. 본 연구결과는 습지토양의 탈질세균 군집이 매우 다양한 종류로 이루어져 있고, 이산화탄소의 증가에도 큰 영향을 받지 않는 상당히 안정적인 우점 개체군이 존재하고 있는 반면, 전체 phylotype의 약 60%는 이산화탄소 증가에 따라 민감하게 변화함을 보여주었다. To investigate the effects of elevated $CO_2$ on the denitrifying bacterial community structure in a wetland soil, dynamics of bacterial community structure was explored in an artificial wetland ecosystem with one of three plant species (T. latifolia, S. lacustris, and 1. effusus) under two levels of $CO_2$(370 ppm or 740 ppm) after 110day incubation. For the analysis of bacterial community structure, functional genes such as nitrite reductase genes (nirS) were PCR-amplified followed by cloning of PCR products and screening by restriction fragment length polymorphism (RFLP). nirS gene fragments were amplified in all analyzed soil samples. Species richness estimated by the number of distinct phylotypes were 83 and 95 in the ambient $CO_2$ treatment and the elevated treatment, respectively. Two phylotypes (type 1 and type 2) were dominant in both of the treatments. Elevated $CO_2$ treatment increased species richness of denitrifying as well as changed a large proportion of denitrifier phylotypes compared to those of the ambient treatment. Overall, the data in this study suggested that the denitrifying communities in the wetland soil are diverse and that the richness of denitrifying bacterial community might be affected by elevated $CO_2$ treatment.

III급 부정교합 환자에서 교정 치료 단독 혹은 악교정 수술 병용 여부에 관한 측모 두부계측 방사선사진학적 비교연구

이승훈,남동석,Lee, Seung-Hoon,Nahm, Dong-Seok 대한치과의사협회 1999 대한치과의사협회지 Vol.37 No.5

소아 폐쇄성수면무호흡증후군

이승훈,최지호,Lee, Seung-Hoon,Choi, Ji-Ho 대한수면의학회 2005 수면·정신생리 Vol.12 No.2

Approximately 1% to 3% of all children have obstructive sleep apnea syndrome (OSAS). OSAS in children can lead to a variety of symptoms and sequalae; impairment of development and quality of life, behavioral and personality disturbance, learning problem, cor pulmonale and hypertension. Diagnosis and treatment of OASA for children are different from those for adults in many respects. Adenotonsillar hypertrophy is major cause of childhood OSAS. Overnight polysomnography in a sleep laboratory is the gold standard for diagnosing childhood OSAS. However, because full polysomnography in children may be difficult to obtain, expensive, and inconvenient, other methods to diagnose OSAS have been investigated. Adenotonsillectomy is the most common surgical treatment of childhood OSAS. But if residual symptoms remained after adenotonsillectomy, it should be considered to additional treatment such as weight control, sleep positional change, and continuous positive airway pressure (CPAP).