Effects of Oral Parafunction on the Stiffness and Elasticity in the Muscles of the Mastication and Facial Expression

김승기,김미은,김기석,Kim, Seung-Ki,Kim, Mee-Eun,Kim, Ki-Suk Korean Academy of Orofacial Pain and Oral Medicine 2008 Journal of Oral Medicine and Pain Vol.33 No.1

The purpose of this study was to evaluate the effects of oral habits on the muscles of mastication and facial expression by means of two parameters: muscle stiffness and elasticity. 10 healthy, fully-dentate male subjects in their twenties were selected for this study; all had normal Class I occlusal relationships. Muscle stiffness and elasticity were measured with a tactile sensor(Venustron, Axiom Co., JAPAN) while subjects were asked to relax and perform various parafunctional activities such unilateral clenching(biting the bite force recorder with a force of 50kg on each subject's preferred side), jaw thrusting and lip bracing. The following muscles were examined: temporalis anterior(Ta), masseter(Mm), frontalis(Fr), inferior orbicularis oculi(OOci), zygomaticus major(Zm), superior and inferior orbularis oris(OOrs and OOri) and mentalis(Mn). Paired t-test, Correlation Coefficients, ANOVA and Multiple Comparison t-tests were used for statistical analysis. Unilateral clenching was highly correlated with bilateral stiffness and elasticity of all the muscles tested. Mm was affected by all three oral habits; Ta was affected by unilateral clenching(p<0.05); Zm was affected by unilateral clenching and OOrs, OOri and Mn were most affected by lip bracing(p<0.05). This study indicates that not only the masticatory muscles but also the muscles of facial expression, mainly circumoral muscles, can be significantly influenced by parafunctional activities such as unilateral clenching and lip bracing.

댐 하류 하천에서 하상변동 모델을 이용한 어류 물리서식처 변화 모의

김승기,최성욱,Kim, Seung Ki,Choi, Sung-Uk 응용생태공학회 2015 Ecology and resilient infrastructure Vol.2 No.4

본 연구는 장기하상변동 모의를 이용하여 댐 하류 하천에서의 하상변동이 어류 물리서식처에 미치는 영향에 대하여 연구하였다. 이를 위하여 흐름모형은 준정류 모형을 이용하였으며, 서식처 모형은 서식처 적합도 지수 (HSI) 모형을 이용하였다. 장기하상변동 모의를 위하여 Exner 방정식을 이용하였으며 하상재료 입도분포의 변화를 고려하였다. 내성천 영주댐 하류에서 모의결과 침식과 장갑화가 진행되었으며 이에 따라 피라미의 물리서식처가 변하게 되었다. 지형과 하상재료의 변화가 어류 물리서식처에 영향을 끼치는 것을 확인할 수 있다. This study investigated the impact of the morphological change on a physical fish habitat in the downstream reach of a dam using long-term mobile bed simulation. The quasi-steady model was used for hydraulic simulation and the habitat suitability index model was applied for physical habitat simulation. For simulating long-term morphological change of the stream bed, The Exner equation was used. Sorting of bed material was also considered. The results of simulation showed that erosion and armoring process occurred in a reach downstream of the dam and change of physical habitat for Zacco platypus followed. These results indicate that channel morphology and substrate conditions effected the physical habitat for considering long-term investigation.

유리염소 측정을 위한 일회용 스트립 센서

김승기,강태영,차근식,남학현,신재호,Kim, Seung Ki,Kang, Tae Young,Cha, Geun Sig,Nam, Hakhyun,Shin, Jae Ho 한국전기화학회 2012 한국전기화학회지 Vol.15 No.4

수질 분석에서 염소 소독제 잔류량 측정은 세균학적 안전성 확보와 염소의 과다 주입을 억제하기 위한 수단으로 매우 중요한 의미를 갖는다. 이러한 휴대용 잔류염소 측정기 개발을 위한 일회용 유리염소 스트립 센서를 스크린 프린팅 기술을 이용한 탄소 전극으로 제작하였다. 탄소 전극은 금과 백금 전극에 비해 결합염소(특히 $NH_2Cl$) 방해종에 대한 영향이 적었으며, -0.3 V(vs. Ag/AgCl) 인가전위에서 유리염소에 대해 안정한 감응성을 나타냈다. 이렇게 제작된 탄소 전극에 모세관현상으로 일정량의 시료를 재현성 있게 도입할 수 있는 유로구조를 갖는 일회용 스트립센서로 제작하였고, 잔류 유리염소의 분석에 적용하였다. The measurement of residual chlorine as a disinfectant is very important to ensure the safety against the pathogenic microbes and to suppress injection. The portable free chlorine sensor was fabricated with a disposable strip format by a screen printing method. The strip sensors prepared with a carbon-Ag/AgCl(cathode-anode) combination exhibited less interfering responses towards combined chlorine species(especially $NHCl_2$) and oxygen than the sensors prepared with other metals(i.e., gold and platinum). Free chlorine was determined chronoamperometrically with carbon-based electrodes at an applied potential of -0.3 V(vs. Ag/AgCl). A channel was built on the strip-type electrode for easy sampling, and the resulting strip sensors were employed to determine the concentrations of residual free chlorine.

Q10 더미를 이용한 어린이용 안전장치 동적 성능 평가

김승기,오형준,Kim, Seungki,Oh, Hyungjoon 한국자동차안전학회 2015 자동차안전학회지 Vol.7 No.1

Recently, Child safety has become one of the issue with Q10 dummy representing large child. The objective of this paper was to evaluate performance of three child restraints system (backless booster, high-back booster and without booster) by changing D-ring location in the rear seat. Sled tests were carried out with a Q 10 in 64km/h frontal impact. Before the dynamic sled tests, we assessed dummy positioning with difference in CRS types and height adjustment positions. Dynamic sled test results indicated that there is different performance of CRS types and belt routing. These test results will use as base line data for development CRS safety performance for Q 10.

기증자 이야기

김승기,노희령,남삼현,류대열,임지연,신봉식,Kim, Seung-Gi,No, Hui-Ryeong,Nam, Sam-Hyeon,Ryu, Dae-Yeol,Im, Ji-Yeon,Sin, Bong-Sik 한국조혈모세포은행협회 2002 나누는사람들 Vol.21 No.-

환경생태유량 취약성 평가 및 자연유황 회복을 위한 환경생태유량 산정 기술

김승기,강형식,전동진,Kim, Seung-Gi,Gang, Hyeong-Sik,Jeon, Dong-Jin 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.9

댐 건설에 따른 하류 하도 어류 서식처 변화 분석

김승기,최성욱,Kim, Seung Ki,Choi, Sung-Uk 응용생태공학회 2014 Ecology and resilient infrastructure Vol.1 No.2

Dam construction changes flow regime and stream morphology in the downstream reach. These affect the ecosystem of downstream reach. This study provides the assessment of the impact of dam construction on the downstream fish habitat. For this, physical habitat simulations are carried out. The quasi-steady model is used for hydraulic simulation, The hydraulic model used in the present study is capable of simulating the morphological change due to sediment transport. The change of the fish habitat condition is investigated using the flow scenarios before and after the dam construction. Simulation results indicate that the habitat suitability decreases frequently due to hydropeaking after dam construction. In addition, erosion is expected to occur in a reach downstream of dam. This is a long term effect due to the shut-down of sediment supply from the upstream reach. 댐의 건설은 유황의 변동과 유사의 흐름을 차단하기 때문에 하천의 수리학적 환경에 큰 영향을 미치게 된다. 본 연구의 목적은 댐의 건설이 댐 하류의 어류의 서식처에 미치는 영향을 분석하는 것이다. 이를 위해 준정류 모형이 흐름모의에 사용되었으며, 물리 서식처 분석을 위해 HSI 모형을 사용하였다. 본 연구에서 사용된 수리모형은 유사이송에 의한 이동상 모의가 가능하다. 유량 시나리오를 통해 댐 건설 전과 후의 피라미에 대한 어류 서식처 조건을 분석하였으며, 모의 결과 댐 건설 후 발전방류로 인하여 피라미의 서식처가 악화되는 빈도가 늘어났다. 또한 댐 하류로부터의 침식이 예측되었다. 이는 상류의 유사량 공급의 차단으로 인하여 나타나는 장기적인 변화이다.

전적출후 재발한 소아 두개인두종의 재발인자에 대한 분석

김승기,왕규창,정영섭,심기범,조병규,Kim, Seung-Ki,Wang, Kyu-Chang,Chung, Young Seob,Sim, Ki-Bum,Cho, Byung-Kyu 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.1

Objectives : A substantial number of craniopharyngiomas recur despite gross total excision. The purpose of our study was to investigate pattern of recurrence and to verify prognostic factors for recurrence after gross total excision of craniopharyngiomas in children. Methods : A series of 36 patients with craniopharyngiomas were reviewed. All patients had undergone gross total excision and none of them received radiotherapy after initial surgery. Fifteen were girls and twenty-one were boys, with a mean age of 7.3 years(range, one to 15 years). The mean follow-up period was 52 months(range, one to 149 months). Recurrence was noted in 14 patients within 83 months(mean 31.4 months). Results : The overall three-year recurrence free survival rate was 65%, and the five-year recurrence-free survival rate was 55%. Regular neuroimaging follow-up at six to 12-month intervals detected tumor recurrence of a smaller size before symptoms developed(p<0.05). At the first surgical procedure, the optic nerve/chiasm(n=23) was the most common adhesion site. The most frequent sites of recurrence were the optic nerve/chiasm(n=6) and the pitiutary fossa(n=6). Tumor location was the single significant clinical predictor of recurrence. The five-year recurrence-free survival rate was 39% for those who had an intrasellar tumor component and 81% for those who did not (p<0.05). Conclusion : Craniopharyngiomas with intrasellar components should be followed cautiously and regular followup of patients should be emphasized, even when the tumors are totally resected.

깔짚 두께가 한우사 바닥환경과 생산성에 미치는 영향

김승기,박병기,안준상,박명호,라창식,신종서,Kim, Seung-Gi,Park, Byung-Ki,An, Jun-Sang,Park, Myung-Ho,Ra, Chang-Six,Shin, Jong-Suh 한국축산환경학회 2012 축산시설환경학회지 Vol.18 No.suppl.

본 연구는 깔짚 두께가 한우의 사료섭취량, 혈액성상 및 바닥 환경에 미치는 영향을 검토하기 위해 수행되었다. 사료 섭취량은 깔짚의 두께가 얇은 것보다 두꺼울 때 증가되는 경향을 보였다. 깔짚 두께의 증가는 혈중 total protein, HDL-cholesterol, LDL-cholesterol 및 GGT 농도에 긍정적인 영향을 미쳤다. 깔짚의 수분 함량 및 대장균수는 깔짚의 두께 10 cm 보다 15 및 20 cm에서 뚜렷하게 낮은 결과를 보였다. 따라서 한우의 건강과 생산성 향상을 위해서는 깔짚의 두께는 20 cm 정도가 이상적이며, 최소한 깔짚의 두께는 15 cm 이상을 유지하는 것이 바람직한 것으로 판단된다. This study was conducted to investigate the effects of bedding thickness of sawdust on feed intake, blood metabolites concentration and environmental condition of cowshed floor for Hanwoo. Feed intake was increased at thicker bedding groups (15 or 20cm), compared with thinner bedding group (10cm). The thicker bedding had a positive effect on concentration of serum total protein, high density lipoprotein (HDL)-cholesterol, low density lipoprotein (LDL)-cholesterol and ${\gamma}$-glutamyltransferase (GGT). Moisture content and the number of E. Coli in the bedding material were remarkably lower in 15 and 20 cm groups, compared with 10 cm group. Based on the data obtained in this study, approximately 20 cm bedding thickness or at least over 15 cm would be maintained to improve the health condition of Hanwoo and hence to enhance the productivity.

정강성을 고려한 5축 복합가공기의 리브 구조 최적설계

김승기(Seung-Gi Kim),김지훈(Ji-Hoon Kim),김세호(Se-Ho Kim),윤재웅(Jae-Woong Youn) 한국생산제조학회 2016 한국생산제조학회지 Vol.25 No.5