일체형 완속교반/침전 그물망 압착식 섬유여과장치를 이용한 하수처리장 반류수 내 고농도 인 및 부유물질 처리

김정숙 ( Jeongsook Kim ),김민호 ( Min-ho Kim ),김미란 ( Mi-ran Kim ),장정국 ( Jeong-gook Jang ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.6

하수 및 폐수 내 고농도의 인 및 부유물질 제어를 위해 개발한 일체형 완속교반/침전 그물망 압착식 섬유여과시스템을 이용하여 하수처리장의 반류수 내 부유성 고형물 및 인 처리에 적용했을 경우에 따른 성능을 검토하고자 하였다. 6가지 Mode로 실험을 하였으며, 16.7, 33.3, 41.7 및 50.0 ton/day 유량과 Al/P 몰비 2~4의 조건에서 실험을 행하였다. 응집제를 주입하였을 경우에 모두 높은 총인(T-P) 제거 효율을 보였지만 연속운전시간이 7.8 min~11.4 min으로 짧아지는 단점이 생겼다. 이를 극복하기 위해 일체형 완속교반/침전 그물망 압착식 섬유여과시스템을 응집/급속교반/공기주입/완속교반/침전공정 및 여과공정으로 진행 시 연속운전시간이 88.2 min으로 다른 모드로 운전한 결과에 비해 8~11.3배 정도 증가하였다. 역세수량율도 5.4%로 매우 낮게 나타남에 따라 이 공정이 가장 효율적인 처리방안으로 평가되었다. An integrated slow mixing/sedimentation and net fit fiber filtration system has been developed to reduce the high concentrations of suspended solid (SS) and total phosphorus (T-P) in the reject water from sewage/wastewater. A filtration device used in this experiment consists of coagulation, in-line mixing, air injection, slow mixing/sedimen-tation, and filtration processes. The performance test using this device was carried out with six operational modes for reject water from sewage treatment plant. Experimental conditions used were 16.7, 33.3, 41.7 and 50.0 ton/day of flow rate and 2~4 of Al/P molar ratio. By injection of coagulant in each operational mode, the high removal efficiencies of SS and T-P were obtained, but continuous operation time was decreased to 7.8~11.4 min in most modes. However, when the Mode 5 of the developed filtration device was applied, the continuous operation time was maintained up to 88.2 min. Also, it was found that the continuous operation time in the Mode 5 using the developed system was increased from 8 to 11.3 times longer than those in other modes. Backwashing flow rate was also very low at 5.4% of total filtered water. Therefore, it can be concluded that the Mode 5 of the developed filtration system was the most efficient treatment method for the removal of high concentrations of SS and T-P.

철 석출장치가 결합된 무산소.호기공정에 의한 인 제거 특성

김민호,김영규,김수복,Kim, Min-Ho,Kim, Young-Gyu,Kim, Soo-Bok 한국환경보건학회 2010 한국환경보건학회지 Vol.36 No.6

In this study, the (phosphorous removal) the characteristics of phosphorous removal due to (the iron compound precipitated) iron compound precipitation by iron electrolysis in (the anoxic. oxic process) anoxic and oxic processes (equipped with the) in an iron precipitation device were analyzed. During the device operation period, the average concentration of BOD, T-N, and T-P were 219.9 mg/l, 54.6 mg/l and 6.71 mg/l, respectively. The BOD/$COD_{Cr}$ ratio was 0.74, and the BOD/T-N and BOD/T-P ratios were 4.0 and 32.8, respectively. The removal rate of (the organic matters) organic matter (BOD and $COD_{Cr}$) was very high at 91.6% or higher, and that of nitrogen was 80.5%. The phosphorous concentration (of the final) in the treated water was 0.43 mg/l (0.05-0.74 mg/l) on average, and the removal efficiency was high at 90.8%. The soluble T-P concentrations in (an) the anoxic reactor, oxic reactor (II) and final treated water were 1.99 mg/l, 0.79 mg/l and 0.43 mg/l, respectively, which indicated that the phosphorous concentration in the treated water was very low. Regardless of the changes in the concentrations of (organic matters) organic matter, nitrogen and phosphorous in the influent, the quality of the treated water was relatively stable and high. The removal rate of T-P somewhat increased with the increase in the F/M ratio in the influent, and it also linearly increased in proportion to the T-P loading rate in the influent. In the treatment process used in this study, phosphorous was removed (using) by the precipitated iron oxide. Therefore, the consumption of organic (matters) matter for biological phosphorus removal was minimized and (most of the organic matters were) was mostly used as the organic carbon source for the denitrification in the anoxic reactor. This (can be an economic) treatment process (without the need for the supply of additional organic matters) is economic and does not require the supply of additional organic matter.

저가형 GPS와 INS를 이용한 복합항법 시스템 개발

김민호,송현민,김정래,Kim, Min-Ho,Song, Hyun-Min,Kim, Jeong-Rae 항공우주시스템공학회 2010 항공우주시스템공학회지 Vol.4 No.3

GPS sensors provide accurate position and velocity of moving vehicles. However, GPS is weak at intermittent signal loss and large position error. Combination with INS improves the GPS position accuracy during the GPS signal loss. In this paper, a fusion filter using GPS and INS is developed and its perfomance is analyzed with RC car and RC airplane experiments.

검사노드 갱신 과정에서 발생하는 중복 연산을 제거한 수정된 Extended Min-Sum LDPC 복호기

김민호(Kim Min-Ho),박경빈(Park Kyeong Bin),정기석(Chung Ki-Seok) 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.2

산화물 분산강화형 316L 스테인리스강의 제조와 특성 연구

김민호,류호진,김성수,한창희,장진성,권오종,Kim, Min-Ho,Ryu, Ho-Jin,Kim, Sung-Soo,Han, Chang-Hee,Jang, Jin-Sung,Kwon, Oh-Jong 한국분말야금학회 2009 한국분말재료학회지 (KPMI) Vol.16 No.2

Austenitic oxide-dispersion-strengthened (ODS) stainless steel was fabricated using a wet mixing process without a mechanical milling in order to reduce contaminations of impurities during their fabrication process. Solution of yttrium nitrate was dried after a wet mixing with 316L stainless steel powder. Carbon and oxygen contents were effectively reduced by this wet processing. Microstructural analysis showed that coarse yttrium silicates of about 150 nm were formed in austenitic ODS steels with a silicon content of about 0.8 wt%. Wet-processed austenitic ODS steel without silicon showed higher yield strength by the presence of finer oxide of about 20 nm.

서로 다른 형태의 임플란트의 식립토크가 골에 미치는 열변화에 관한 연구

김민호,여인성,김성훈,한중석,이재봉,양재호,Kim, Min-Ho,Yeo, In-Sung,Kim, Sung-Hun,Han, Jung-Seok,Lee, Jai-Bong,Yang, Jae-Ho 대한치과보철학회 2011 대한치과보철학회지 Vol.49 No.2

연구 목적: 임플란트 식립시에 발생할 수 있는 열변화는 임플란트의 실패를 초래할 수 있다. 식립토크에 따른 열변화 양상을 파악함으로 임플란트의 형태에 따른 차이점과 적절한 식립토크가 어떤 것인지 파악하고자 한다. 연구 재료 및 방법: 실험재료로는 두께 15 - 20 mm의 소 견갑골을 가로 35 mm, 세로 40 - 50 mm 크기가 되도록 골편으로 자르고 이중에 피질골의 두께가 2 - 3 mm 되는 표본을 선정한 후 표본의 반을 $36.5^{\circ}C$ 수조에 실온 $25^{\circ}C$에 노출 시켜 내부 온도는 평균 $36.5^{\circ}C$, 표면온도 $28^{\circ}C$가 되도록 설계하였다. $4.5{\times}10\;mm$의 외부육각을 가지는 Br${\aa}$nemark 형태의 임플란트와 $4.8{\times}10\;mm$의 Microthread 형태를 지니는 내부연결 형태의 임플란트를 과도한 식립토크로 식립하고 온도 측정은 계측점에서 0.2 mm 이내에 열전대를 위치시켜 기록하였다. 삼차원유한요소 분석은 골의 형태를 가로 4 cm, 세로 4 cm, 높이 2 cm의 직육면체로 가정하고, 직육면체 윗면에서 2 mm까지를 피질골, 그 아랫부분을 해면골이라고 가정하였다. 마찰열은 매식이 종료된 상황에서 골에 남는 cavity 모양을 기초로 경계조건을 부여하였다. CAD 프로그램인 SolidWorks 소프트웨어를 이용하였고, 이를 유한요소 구조해석용 프로그램인 Abaqus 6.9-1로 불러들여 해석하였다. 결과 및 결론: In vitro실험에서 Microthread type의 임플란트가 상대적으로 더 높은 최고점 온도를 보여주고 있으며 이는 임플란트의 형태에 따른 마찰열 발생이 주요 원인으로 보인다. 유한요소분석을 통해 살펴본 결과 Br${\aa}$nemark 형태의 임플란트의 경우 50 Ncm이상에서 Microthread를 가지는 형태의 경우에는 35 Ncm이상에서 Eriksson 등이 보고한 역치를 초과하는 온도가 발생하였다. 이를 통해 볼 때 Microthread type 이 식립토크에 따른 온도 증가가 더 민감함을 알 수 있다. 실험결과를 통해서 서로 다른 형태의 임플란트 식립시에 임플란트의 형태에 따라 적절한 삽입토크를 부여하는 것이 성공적인 임플란트 시술에 중요한 요소 중에 하나임을 알 수 있었다. 특히 Microthread를 갖는 임플란트 형태는 높은 초기고정성을 얻을 수 있다는 장점이 있는 반면 과도한 식립 토크로 인한 열 손상 가능성을 가질 수 있으므로 골량과 골질의 신중한 평가와 적절한 수술기법이 필요할 것으로 생각된다. Purpose: This study aims at investigating the influence of various insertion torques on thermal changes of bone. A proper insertion torque is derived based on the thermal analysis with two different implant designs. Materials and methods: For implant materials, bovine scapula bone of 15 - 20 mm thickness was cut into 35 mm by 40 - 50 mm pieces. Of these, the pieces having 2 - 3 mm thickness cortical bone were used as samples. Then, the half of the sample was immersed in a bath of $36.5^{\circ}C$ and the other half was exposed to ambient temperature of $25^{\circ}C$, so that the inner and surface temperatures reached $36.5^{\circ}C$ and $28^{\circ}C$, respectively. Two types of implants ($4.5{\times}10\;mm$ Br${\aa}$nemark type, $4.8{\times}10\;mm$ Microthread type) were inserted into bovine scapula bone and the temperature was measured by a thermocouple at 0.2 mm from the measuring point. Finite element method (FEM) was used to analyze the thermal changes at contacting surface assuming that the sample is a cube of $4\;cm{\times}4\;cm{\times}2\;cm$ and a layer up to 2 mm from the top is cortical bone and below is a cancellous bone. Boundary conditions were set on the basis of the shape of cavity after implants. SolidWorks was used as a CAD program with the help of Abaqus 6.9-1. Results: In the in-vitro experiment, the Microhead type implant gives a higher maximum temperature than that of the Br${\aa}$nemark type, which is attributed to high frictional heat that is associated with the implant shape. In both types, an Eriksson threshold was observed at torques of 50 Ncm (Br${\aa}$nemark) and 35 Ncm (Microthread type), respectively. Based on these findings, the Microthread type implant is more affected by insertion torques. Conclusion: This study demonstrate that a proper choice of insertion torque is important when using a specific type of implant. In particular, for the Microthread type implant, possible bone damage may be expected as a result of frictional heat, which compensates for initial high success rate of fixation. Therefore, the insertion torque should be adjusted for each implant design. Furthermore, the operation skills should be carefully chosen for each implant type and insertion torque.

임플란트 매식 시 수직골 높이에 따른 응력분석

김민호,박영록,계기성,Kim, Min-Ho,Park, Young-Rok,Kay, Kee-Sung 대한턱관절교합학회 2002 구강회복응용과학지 Vol.16 No.3

The purpose of this study was to compare the distributing pattern of stress on the finite element models with the different vertical bone level of implant fixture. The two kinds of finite element models were designed according to vertical bone level around fixture ($4.0mm{\times}11.5mm$). The cemented crowns for mandibular first and second molars were made. Three- dimensional finite element model was created with the components of the implant and surrounding bone. Vertical loads were applied with force of 200N distributed within 0.5mm radius circle from the center of central fossa and distance 2mm and 4 mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the supporting bone, fixtures, abutment screws, and crown. The results were as following : (1) In vertical loading at the center circle of central fossa on model 1 and 2, the difference from vertical bone in implant placement did not affect the stress pattern on all components of implant except for crown. (2) With offset distance incerasing and the bone level of implant decreasing, the concentration of stress occured in the buccal side of long crown, around the buccal crestal bone, and on the fixture- abutment interface. As a conclusion, the research showed a tendency to increase the stress on the supporting bone, fixture and screw under the offset loads when the vertical level of bone around fixture was different. Since the same vertical bone bed has more benefits than the different bone bed around fixtures, it is important to prepare a same vertical level of bone bed for the success of implants under occlusal loads.

산사태위험지도를 이용한 도로중심 복합재난 위험도 평가

김민호,장창덕,전계원,Kim, Min-Ho,Jang, Chang-Deok,Jun, Kye-Won 한국방재안전학회 2022 한국방재안전학회 논문집 Vol.15 No.3

국내 재해위험지도는 주로 격자단위 및 재해 유형별 단일 재해지도로 제작 및 연구되고 있어 도로관리 중심으로 접근할 경우 그 활용도가 떨어진다. 특히 주로 시설의 유지관리를 담당하는 실무자의 업무활용을 위해서는 보다 해당시설 (지방도로)에 맞는 재해위험지도의 평가방법을 제시할 필요가 있다. 본 연구에서는 산림청에서 제공하고 있는 산사태위험지도 및 토석류위험지도를 활용하여 지방도를 중심으로 위험도를 평가할 수 있는 평가방법을 제시하였다. 또한 강원도에 위치한 지방도를 대상으로 위험도를 평가하고 검증하였다. 평가결과 총연장 234.59 km의 평가구간에서 1,513개의 평가구간에 대한 1~5등급의 위험도를 평가할 수 있었다. Domestic disaster risk maps are mainly produced and studied as a single disaster map by grid unit and disaster type. In particular, it is necessary to present an evaluation method of the disaster risk map that is more suitable for the relevant facility (local road) in order to utilize the work of practitioners who are mainly in charge of facility maintenance. In this study, an evaluation method was presented to evaluate the risk with a focus on local roads by using the landslide risk map and debris flow risk map provided by the Korea Forest Service. In addition, the risk was evaluated and verified for the provinces located in Gangwon-do. As a result of the evaluation, it was possible to evaluate the risk of grades 1 to 5 for 1,513 evaluation sections in the evaluation section with a total length of 234.59 km.

후두외상 후 발생한 저음발성 여자환자에서의 라디오전파를 이용한 음도상승 유도 치료 1예

김민호,송기재,최홍식,Kim, Min-Ho,Song, Ki-Jae,Choi, Hong-Shik 대한후두음성언어의학회 2006 대한후두음성언어의학회지 Vol.17 No.1

The factors involved in controlling the vocal pitch are the tension, the mass, the length of the vocal cords and the subglottic pressure. Vocal pitch can be elevated surgically by increasing the stiffness or reducing the vibrating mass of the vocal cords. Recently, we experienced a case of 25 year-old female whose vocal pitch was elevated with radiofrequency surgery of right vocal cord on suspension laryngoscopy. Elevation of vocal pitch(134.11 to 144.73) was noted two months after operation. So we report this case with review of literature.

백내장 수술이 안구박동크기에 미치는 영향

김민호,양홍석,이마빈,안재홍.Min Ho Kim. MD. Hong Seok Yang. MD. PhD. Mar Vin Lee. MD. Jae Hong Ahn. PhD 대한안과학회 2012 대한안과학회지 Vol.53 No.12

Purpose: To investigate the change of intraocular pressure (IOP) and ocular pulse amplitude (OPA) measured by dynamic contour tonometry (DCT) after cataract surgery and to identify the influencing factors related with OPA change after cataract extraction. Methods: The present study included 32 patients who underwent unilateral cataract surgery and the non-operated fellow eyes were used as control. IOP was measured by Goldman applanation tonometry (GAT) and Pascal DCT preoperatively, and 3 months postoperatively. Additionally, OPA was measured by Pascal DCT preoperatively, and 3 months postoperatively. Axial length (AL), anterior chamber depth (ACD), and central corneal thickness (CCT) were measured preoperatively. Results: After cataract surgery, IOP by GAT, IOP by DCT, and OPA decreased significantly with a mean decrement of 1.3 mm Hg, 1.6 mm Hg, and 0.5 mm Hg, respectively (p < 0.05). OPA was significantly correlated with IOP by GAT (r = 0.497, p = 0.004) and IOP by DCT (r = 0.421, p = 0.016) preoperatively. OPA was correlated with GAT (r = 0.357, p = 0.045) but not with DCT (r = 0.224, p > 0.05) postoperatively. The most important factor influencing the decrement of IOP by GAT, IOP by DCT, and OPA after cataract surgery was the preoperative level of their measurements (r = 0.382, p < 0.05 in GAT, r = 0.807, p < 0.001 in DCT, r = 0.627, p < 0.001 in OPA). In addition, the OPA decrement after cataract surgery was significantly correlated with age (r = -0.370, p = 0.037), and was not correlated with AL, ACD, and CCT. Conclusions: Both IOP and OPA decreased after cataract surgery, which appears to influence the relationship between IOP and OPA. The correlation between OPA decrement and age may be related to increased ocular rigidity with aging.