학교소음이 학업성취에 미치는 영향

정경훈,박상일,강영주,위환,염동익 조선대학교 환경공해연구소 2006 環境公害硏究 Vol.19 No.1

The reason for the school noise problem located in the city is due to the fact that this noise is aroused by the development of industrial facilities that give too much importance to certain provinces and the cityward tendency of the population and so on. which is scattered nearby school, In addition, the indoor noise caused by the students themselves is loud. It damages the environment as would a loudspeaker, and the noise from the school itself compounded with the noise from outside raises a serious problem. Measure and analysis of the actual condition of this school noise shows its influence and effect on scholastic achievement. Noise can be felt through a man's sense, and it can be felt differently according to an individual's habit, and the time and place. That's why the physical amount, which is measured by a measuring instrument, can't display the grades of noise. The results of a survey show that students' attitudes toward noise and the students' psychological reactions are more apparent in those who take part in classes located in the south building, which is exposed to a large amount of noise from highway traffic. One important factor in the different degrees of school noise is that it becomes louder as one travels higher within the building. We can determine the different effects by comparing the scores of students from various classes. For instance, the scores of students who are exposed to this noise will be compared with those who are not. To survey how much the students themselves are effected by the noise in their studying atmospheres, we selected the north building, which the noise does not penetrate as readily as it would another building and where the measure of the noise amount(Leq, 10 min.). As a result, the classes' records will show the data between the areas where the amount of noise is high and those where the amount of noise is low. It is economically and actually difficult to make a countermeasure for the schools that are influenced by noise, but we should make plans to allocate flexible arrangements of classes and time tables, and to create a good environment for teachers to utilize their professionalism in their own subjects, a variety of teaching skills and the teaching techniques necessary to work with the various levels of the students.

알루미늄의 전기분해를 이용한 인 제거

정경훈,최형일,정오진,최칠남,정재경 한국환경과학회 2000 한국환경과학회지 Vol.9 No.1

Laboratory experiments were performed to investigate the effects of various factors on the phosphorus removal by electrolysis with aluminium electrodes. The efficiency of phosphorus removal increased with increasing of voltage applied, surface area of electrodes and electrolyte concentration, and decreasing of electrode distance. The phosphorus removal was not affected by the connection number of an electric circuit. The amount of aluminium ion eluted from electrodes according to Faraday's law was 4.47 ㎎ and the Al/P mole ratio was 2.14 at the electric current value of 20 ㎃.

페탄광 주변 하천의 수질조사

정경훈,최형일,정오진,정재경,강성환,조영찬 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

The Water quality for river surrounding closed coal mine in Hwasun area Chunnam was investigated. The investigated factors were pH, turbidity, conductivity, Fe, SO_(4)^(-2), Ca, and Mg concentration, and the crystallization form and components of suspended solids were also investigated by scanning electron microscope and energy dispersion system Extremely high value of turbidity and conductivity were represented in Honam Kwangup (N-7) and Honam Tanza (N-3)area, respectively. Fe concentration was lower in all sampling sites, and the concentration of SO_(4)^(-2) ion was higher than 200mg/L in all sampling sites excepting Dongyang Tanggwang area (N-2) and Hwail wetland (N-11). The SEM micrograph and EDS analysis showed that the crystallization form of the suspended solids was formless, These particles have size of less than 10??and the main components was O, Al, Fe and S. The corelation values between conductivity and Mg, SO_(4)^(-2), and Ca were 0.967, 0.959, 0.931, respectively, and the results indicate good corelation.

폐탄광 주변 하천의 수질조사

정경훈,최형일,정오진,정재경,강성환,조영찬 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

The Water quality for river surrounding closed coal mine in Hwasun area Chunnam was investigated. The investigated factors were pH, turbidity, conductivity, Fe, SO_^-2, Ca, and Mg concentration, and the crystallization form and components of suspended solids were also investigated by scanning electron microscope and energy dispersion system. Extremely high value of turbidity and conductivity were represented in Honam Kwangup (N-7) and Honam Tanza (N-3)area, respectively. Fe concentration was lower in all sampling sites, and the concentration of SO_4^-2 ion was higher than 200㎎/L in all sampling sites excepting Dongyang Tanggwang area (N-2) and Hwail wetland (N-11). The SEM micrograph and EDS analysis showed that the crystallization form of the suspended solids was formless, These particles have size of less than 10㎛ and the main components was O, Al, Fe and S. The corelation values between conductivity and Mg, SO_4^-2, and Ca were 0.967, 0.959, 0.931, respectively, and the results indicate good corelation.

쓰레기 종량제 개선에 대한 평가 연구

정경훈,최형일,김정애,박상일 조선대학교 환경공해연구소 2007 環境公害硏究 Vol.20 No.1

It is ten years since the volume based waste free system carried out. This aimed to analysis and estimate about the achievement of the volume based waste free system of the Ministry of Environment and Damyang-Gun. According to the analysis of its result, it is still unsatisfied to use the plastic bags of the volume based waste free system and to separate and throw away the wastes. The Public Opinion says that the Government needs to further step up publicity activities on the volume based waste free system by making good use of TV, newspaper, and magazine, and should offer the incentives to people who observe the volume based waste free system, In addition, it says that people in Damyang-Gun incinerate illegally(60.5%). Therefore. the study and supply of waste disposal method is necessary to people in Damyang-Gun, manufacturers themselves should collect wastes, and Damyang-Gun should expend the systematical device of collecting wastes. If these things go on, the volume based waste free system will be fixed.

하악전돌증 환자의 악교정 수술후 경조직과 연조직 변화에 관한 두부방사선 계측학적 연구

최유경,서정훈 대한치과교정학회 1993 대한치과교정학회지 Vol.23 No.4

The purpose of the study is to estimate hard and soft tissue after orthognathic surgery for the correction of the mandibular prognathism and to describe interrelationship and ratios of soft and hard tissue changes. The presurgical and postsurgical lateral cephalograms of 31 treated patients(17 males and 14 females) was used ; these patients had received combined orthodontic-surgical treatment by means of a bilateral sagittal split ramus osteotomy. Their ages ranged from 16 to 31 years and mean age was 21.4 years. A computerized cephalometric appraisal was developed and used to analyse linear and angular changes of skeletal and soft tissue profile. The statistical elaboration of the data was made by means of SPSS/PC^+ The results of the study were as follows : 1. The correlations of soft and hard tissue horizontal changes were significantly high and the ratios were 97% at LI, 107% at ILS, and 93% at Pog'. 2. The correlations of vertical changes at Stm, LI and horizontal changes at Pog were high(26%) and at the other areas were not statistically high. 3. The correlations of soft ad hard tissue vertical changes were not significantly high in all areas except Gn' (30%) and Me'(56%). 4. The soft tissue thickness was significantly decreased in upper lip and increased in lower lip, and the amount of changes after surgery was reversely correlated with initial thickness. 5. The facial convexity was increased and relative protrusion of upper lip was increased and that of lower lip was decreased. 6. The upper to lower facial height(G1-Sn/Sn-Me') was increased and upper to lower jaw height(Sn-Stms/Stmi-Me') was increased.

대구치 직립 스프링 적용시 반작용에 관한 삼차원 유한요소법적 연구

최유경,김태우,서정훈 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.1

하악 제1대구치가 상실되고 하악 2대구치가 근심으로 경사된 겨우 이를 직립시키기 위하여 직립 스프링을 사용하였을때 초기에 나타나는 응력 분포와 치아의 변위 양상을 살펴보고 여러 조건하에서의 변화를 비교, 분석하여 바람직하지 못한 치아 이동을 감소시키기 위한 방안을 모색하고자 본 연구를 시행하였다. 3차원 유한요소법을 이용하여 하악치아, 치근막과 치조골의 형태와 물리적 특성을 컴퓨터로 재현시키고 브라켓을 모형화하여 치아에 부작한 후 helical spring, root spring, T-loop, box loop등 5가지 형태의 스프링을 beam요소로 모형화하여 적용시켜 유한요소 모델을 제작하였다. 스프링의 형태, cinch-back여부, activation 양, tip-back bend의 크기에 따른 차이를 보기 위하여 여러 조건하에서 탄선 적용시 나타나는 힘과 모멘트, 치아이동 변위를 개개치아의 FA point에서 계측하여 비교, 분석한 결과 다음과 같은 결론을 얻었다. 1. Helical spring과 root spring적용시 하악 견치와 제1소구치의 압하가 일어났고, 하악 제2대구치의 원심이동과 정출, 원심회전이 일어났다. 2. T-loop, modified T-loop, box loop 적용시 하악 제2소구치의 압하와 원심이동이 일어났고, 하악 제2대구치의 직립에 필요한 원심이동과 원심회전은 T-loop에서 가장 크게 나타나고, box loop에서 가장 작게 나타났다. 3. T-loop에서 cinch-back을 한 경우 하악 제2대구치 치관의 원심이동과 원심회전은 약간 감소하였으나, 치아의 정출도 동시에 감소하였다. 4. T-loop에서 activation양을 증가시킴에 따라 하악 제2대소구치의 근심이동이 점차 증가하여 공간폐쇄 경향을 보였고, 치관의 원심회전 역시 점차 증가하였으나, 하악 제2소구치의 원심 이동도 약간 증가하였다. 5. T-loop에서 tip-back bend의 양을 증가시킴에 따라 하악 제2대구치의 직립에 필요한 원심이동과 원심회전이 점차 증가하였으나, 치아의 정출은 더욱 급격히 증가하였다. The purpose of this study was to investigate the stress distribution and tooth displacement at the initial phase produced by 5 type of molar uprighting springs using finite element method. The three dimensional finite element model of lower dentition, bone and springs was composed of 5803 elements and 2071 nodes. The results were as follows: 1. In case of helical spring and root spring, intrusion of lower canine and first premolar were observed and distal tipping, translation and extrusion of lower second molar were observed. 2. In case of T-loop, modified T-loop and box loop, intrusion and distal translation of lower second premolar were observed, and the largest crown distal tipping and translation of lower second molar were observed in T-loop and the smallest were observed in box loop. 3. In case of T-loop with cinch-back, crown distal tipping and translation of lower second molar were decreased, but extrusion was also decreased. 4. With increase of activation in T-loop, mesial translation and crown distal tipping of lower second molar were increased and edentulous space was closing, but distal translation of second premolar was also increased. 5. With increase of tip-back bend in T-loop, distal tipping and translation of lower second molar were increased, but extrusion was also increased more largely.

건설공사로 인한 소음·진동 민원대책에 관한 연구

최형일,정경훈 조선대학교 환경연구소 2001 環境硏究 Vol.17 No.2

Urban construction work has been caused much annoyance recentry. But construction noise standard of our country is inefficient. Especially, diesel pilling method has caused much problem of highly impactive sound and vibration. Construction works, in order to solve these problem, using oil pressure method of low noise and low vibration equipment. Practical solution for the construction equipment noise, however, are very difficult because of the lack of basic data and insufficiency of the existing research. In this point, this study attempts to surveys the characteristics of attenuation and propagation of construction noise in pillings work using oil pressure method. And this study intends to get the basic data for establishment of a standard about construction equipment noise.

광주시 도로방음벽 실태 조사에 관한 연구

최형일,정경훈,정숙희 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

Our country has been advanced in the organization of society with rapid industralization for more over 30 years. Gravitation of the population and traffic increase made change in life style and brought about a lot of noise pollution which is not able to be confirmed in sight. The damage of traffic noise will be a serious problem, so the effective and economical counter-measuring of noise will be proceeded when we build up a large building or housing complex and it also needs enlightment activity in order to reduce sound by improvement of how to drive. So, It is possible to be suggested as follows 1) Enforcing the every-ten-day limit on auto usage continuously. 2) Expended execution of noise restriction area. 3) Improvement of procedure in parceling-out. 4) Establishment of walfare facilities on the road side. 5) Application of matrial excluded the outside sounds in the construction on road side. If we consider environmental city condition at the construction and city planning, it is possible to minimize the noise pollution, to make a pleasant environment and to contribute the national health improvement.

광주시 도로방음벽 실태 조사에 관한 연구

최형일,정경훈,정숙희 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

Our has been advanced in the organization of society with rapid industralization for more over 30 years. Gravitation of the population and traffic increase made change in life style and brought about a lot of noise pollution which is not able to be confirmed in sight. The damage of traffic noise will be a serious problem, so the effective and economical countermeasuring of noise will be proceeded when we build up a large building or housing complex and it also needs enlightment activity in order to reduce sound by improvement of how drive. So, It is possible to be suggested as follows 1) Enforcing the every-ten-day limit on auto usage continuously. 2) Expended execution of noise restriction area. 3) Improvement of procedure in parceling-out. 4) Establishment of walfare facilities on the road side. 5) Application of matrial excluded the outside sounds in the construction on road side. If we consider environmental city condition at the construction and city planning, it is possible to minimize the noise pollution, to make a pleasant environment and to contribute the national health improvement.