• 한국산림과학회지
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• 제106권1호
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• pp.1-9
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• 2017

산림 벌채 후 형성되는 가장자리 효과의 발생 여부과 회복 과정을 이해하는 것은 생태계 천이와 경관 및 서식지의 공간 영향을 분석하고 이해하는 필수 요소임에도 불구하고, 우리나라에서 관련 주제의 실증 연구는 찾아보기 어렵다. 본 연구는 강원 남부 지역의 소나무림 벌채 후 1, 3, 10, 16년이 경과한 장소에 형성된 벌채지 및 임내 가장자리에서 비생물 및 생물 요인의 변화 양상을 선 (20개) 및 방형구 (340개) 조사법을 병용하여 조사하였다. 벌채 후 초기(3년 이내)는 가장 자리에서 인접 숲 내부 방향으로, 15m 깊이까지 식생 피도, 풍부도, 수관 열림도, 그리고 대기 온도 및 습도가 급격하게 변화하였다. 가장자리 형성 이후, 비생물 요인 및 식물 풍부도의 안정화는 각각 10년 및 16년이 소요되었다. 교목종이 초본식물에 비하여 가장자리 환경에서 더 높은 증가 양상을 나타내었고, 교목종의 높은 증가는 하층식생의 동태에 영향을 주었다. 본 연구 결과를 통해 벌채에 의한 직 간접적인 서식지 변화는 최소 인접 산림의 15 m에서 20 m까지, 그리고 16년 수준까지 지속적으로 영향을 미치는 것으로 나타났다. 본 연구 결과는 경관 및 서식지 패치 평가에 필수적인 가장자리 효과의 깊이에 대한 첫 국내 첫 실증 연구자료로 친환경벌채 기준제시 등 활용성이 높다.

• Journal of Chest Surgery
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• 제2권2호
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• pp.167-167
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• 1969

Two groups of esophagus graft were done in canine esophagus in 34 adult mongrel dogs. For the first group segmental replacement graft was done with fresh autologous pericardium tube, and for the second, patch graft was done utilizing fresh autologous pericardium, fresh homologous pericardium,and dacron piece. All eight dogs in the first segmental replacement graft group died 2 to 5 days after operation with severe empyema caused by anastomosis disruption. Among 26 patch graft dogs 2 died during operation and 7 died 13 to 18 days after operation. For the 17 long-term patch grafted survivors esophagography and postoperative weight check were done. Postoperative stool was collected and examined for dacron patch excretion. One, two, three, and four months postoperative long-term survivors were sacrificed to obtain specimens in each group respectively and the following observations were made.I. Survival; Autologous pericardium patch group showed no mortality but in homologous pericardium and dacron patch group only two thirds were long-term survivors. II. Postoperative swallowing; There was no case which demonstrated postoperative dysphagia. About half of the cases showed postoperative weight increase and in only 3 cases weight decrease followed operation. III. Dacron patch was excreted in the stool 8 to 23 days after operation. Animals which excreted dacron patch up to 9 days after operation all died of empyema due to anastomosis disruption.IV. Postoperative esophagogram; All esophagograms in each group showed no leakage of barium, no passage disturbances and no remarkable stenotic signs.V. Morphological findings; [A] Macroscopical findings; In one month group specimens of each group dense adhesion with surrounding structures was noted and luminal surface was smooth with contraction of the patched area. In two month groups anastomosis sutures were still exposed but patched area showed lesser abnormality. In three to four months groups sutures were covered completely and patched area showed only very slight signs of contraction. [B] Microscopic findings; In one month group luminal surface of the replaced tissue [transplanted tissue] showed almost complete epithelial covering that is composed of several layers of squamous cells with no evidence of keratinization. Basement membrane was also well distinct throughout. Slight to minimal inflammatory cells comprising of large mononuclears, lymphocytes and plasma cells were observed in the subepithelial fibrous stroma consisted entirely of loose fibrous tissue containing many newly formed capillaries and fibroblastic proliferation. Scattered suture granulomas were found, few of which became acutely inflamed. In two months group repairing process progressed with lesser degree of inflammatory cell infiltration and young capillary proliferation. Fibrous tissue was more matured showing even focal collagenization.Suture granuloma persisted but with lesser reactive changes. Epithelial covering was that of a mature non-keratinizing stratified squamous epithelium. In three and four months groups the replaced area showed essentially similar histological findings. However, subepithelial stroma still consisted entirely of connective tissue without evidence of smooth muscle regeneration. In this group, inflammatory cell infiltration was minimal or negligible. Among these patch materials autologous pericardium group showed the most satisfactory repairing process.The above mentioned results may signify the feasibility of autogenous pericardium patch graft in clinical esophageal surgery.

• Journal of Chest Surgery
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• 제2권2호
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• pp.168-186
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• 1969

Two groups of esophagus graft were done in canine esophagus in 34 adult mongrel dogs. For the first group segmental replacement graft was done with fresh autologous pericardium tube, and for the second, patch graft was done utilizing fresh autologous pericardium, fresh homologous pericardium,and dacron piece. All eight dogs in the first segmental replacement graft group died 2 to 5 days after operation with severe empyema caused by anastomosis disruption. Among 26 patch graft dogs 2 died during operation and 7 died 13 to 18 days after operation. For the 17 long-term patch grafted survivors esophagography and postoperative weight check were done. Postoperative stool was collected and examined for dacron patch excretion. One, two, three, and four months postoperative long-term survivors were sacrificed to obtain specimens in each group respectively and the following observations were made. I. Survival; Autologous pericardium patch group showed no mortality but in homologous pericardium and dacron patch group only two thirds were long-term survivors. II. Postoperative swallowing; There was no case which demonstrated postoperative dysphagia. About half of the cases showed postoperative weight increase and in only 3 cases weight decrease followed operation. III. Dacron patch was excreted in the stool 8 to 23 days after operation. Animals which excreted dacron patch up to 9 days after operation all died of empyema due to anastomosis disruption. IV. Postoperative esophagogram; All esophagograms in each group showed no leakage of barium, no passage disturbances and no remarkable stenotic signs. V. Morphological findings; [A] Macroscopical findings; In one month group specimens of each group dense adhesion with surrounding structures was noted and luminal surface was smooth with contraction of the patched area. In two month groups anastomosis sutures were still exposed but patched area showed lesser abnormality. In three to four months groups sutures were covered completely and patched area showed only very slight signs of contraction. [B] Microscopic findings; In one month group luminal surface of the replaced tissue [transplanted tissue] showed almost complete epithelial covering that is composed of several layers of squamous cells with no evidence of keratinization. Basement membrane was also well distinct throughout. Slight to minimal inflammatory cells comprising of large mononuclears, lymphocytes and plasma cells were observed in the subepithelial fibrous stroma consisted entirely of loose fibrous tissue containing many newly formed capillaries and fibroblastic proliferation. Scattered suture granulomas were found, few of which became acutely inflamed. In two months group repairing process progressed with lesser degree of inflammatory cell infiltration and young capillary proliferation. Fibrous tissue was more matured showing even focal collagenization. Suture granuloma persisted but with lesser reactive changes. Epithelial covering was that of a mature non-keratinizing stratified squamous epithelium. In three and four months groups the replaced area showed essentially similar histological findings. However, subepithelial stroma still consisted entirely of connective tissue without evidence of smooth muscle regeneration. In this group, inflammatory cell infiltration was minimal or negligible. Among these patch materials autologous pericardium group showed the most satisfactory repairing process. The above mentioned results may signify the feasibility of autogenous pericardium patch graft in clinical esophageal surgery.

• Animal Bioscience
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• 제34권2호
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• pp.243-255
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• 2021

Objective: Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins that frequently contaminate maize and grain cereals, imposing risks to the health of both humans and animals and leading to economic losses. The gut microbiome has been shown to help combat the effects of such toxins, with certain microorganisms reported to contribute significantly to the detoxification process. Methods: We examined the cecum contents of three different dietary groups of pigs (control, as well as diets contaminated with 8 mg DON/kg feed or 0.8 mg ZEN/kg feed). Bacterial 16S rRNA gene amplicons were acquired from the cecum contents and evaluated by next-generation sequencing. Results: A total of 2,539,288 sequences were generated with ~500 nucleotide read lengths. Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla, occupying more than 96% of all three groups. Lactobacillus, Bacteroides, Megasphaera, and Campylobacter showed potential as biomarkers for each group. Particularly, Lactobacillus and Bacteroides were more abundant in the DON and ZEN groups than in the control. Additionally, 52,414 operational taxonomic units were detected in the three groups; those of Bacteroides, Lactobacillus, Campylobacter, and Prevotella were most dominant and significantly varied between groups. Hence, contamination of feed by DON and ZEN affected the cecum microbiota, while Lactobacillus and Bacteroides were highly abundant and positively influenced the host physiology. Conclusion: Lactobacillus and Bacteroides play key roles in the process of detoxification and improving the immune response. We, therefore, believe that these results may be useful for determining whether disturbances in the intestinal microflora, such as the toxic effects of DON and ZEN, can be treated by modulating the intestinal bacterial flora.

• 한국해양학회지:바다
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• 제29권2호
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• pp.116-138
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• 2024

본 연구는 '해양교란유해종'이 해양 환경과 사회경제적 측면에 미치는 영향을 평가하기 위한 새로운 도구와 프로토콜을 제시한다. 한국의 해양생태계 보전 및 관리법에서 발견된 한계점을 보완하기 위해, 본 연구는 해양 환경과 사회경제 그룹(영역)으로 나누어진 영향 평가 프레임워크를 도입하였다. 각 그룹은 6개의 영향 평가 카테고리(범주)로 구성되어 있으며, 준정량적인 5단계 척도를 사용하여 생태계의 교란에서 건강과 재산에 대한 영향에 이르는 폭넓은 이슈들을 다루는 유연한 방식을 제공한다. 이 영향평가 도구의 실행은 델파이 방법을 기반으로 한 체계적인 5단계 프로세스를 통해 진행된다. 이 접근법은 다양한 전문가와 이해관계자 간의 협력을 촉진하며, 다양한 관점을 통합하는 포괄적인 평가를 가능하게 한다. 또한 이 연구는 불확실성을 효과적으로 관리하고 결과의 일관성을 향상시키는 전략도 모색되었다. 본 평가 프로토콜의 적용은 '해양교란유해종'에 의한 생태학적 피해의 정도를 계량화하고 관리 대상 및 예방 조치의 우선순위를 정립하는 데 결정적인 역할을 할 것으로 기대된다. 평가 과정의 궁극적인 목표는 의사결정자가 해양생태계 보전과 사회경제적 영향을 완화하기 위한 전략을 수립하도록 지원하는 것이다.

• 환경생물
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• 제41권4호
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• pp.400-412
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• 2023

본 연구에서는 과정기반 생지화학모형 중 하나인 BGC-MAN (Biogeochemistry Management) 모형을 남북한에 적용하여 산림생태계의 생산성을 나타내는 지표인 순일차생산성(Net Primary Productivity, NPP)을 평가하였다. 기상자료의 경우에는 우리나라 기상청 기후정보포털의 실측 및 동아시아 시나리오 자료를 병행하여 활용하였다. 식생정보로는 소나무(Pinus densiflora) 및 참나무(Quercus spp.) 임분을 대상으로 우리나라의 광릉 및 설마천 유역과 북한 내 양묘장이 있는 것으로 알려져 있는 사리원, 서흥, 해주, 정주, 원산을 대상지로 선정하였다. 생물리적 정보 중경위도, 고도, 사면 방향 등의 지형정보는 SRTM (Shuttle Radar Topography Mission)의 수치표고모델을 활용하였으며, 토양정보 등의 경우에는 HWSD (Harmonized World Soil Database)의 정보를 활용하였다. 관리 요인의 경우에는 1950년의 한국전쟁으로 인한 남북한 산림파괴와 이후 산림의 재조림 과정을 고려하였다. 1991년부터 2100년까지 모의된 NPP의 전체 평균 값은 5.17 Mg C ha^-1이었으며, 범위는 3.30~8.19Mg C ha^-1로 도출되었다. 또한 기후 시나리오의 변동성이 커짐에 따라서 산림 생산성의 교란이 커졌으며, 소나무 임분의 생장 둔화가 두드러지게 나타났다. 기후변화에 따라 생태계 과정기반 모형의 중요성이 커지는 시점에서 BGC-MAN 모형의 한반도 적용성이 검토되었다. 본 연구의 제한된 자료를 통해서 기후변화에 대한 교란이 산림생태계에 미치는 여러 요인들이 분석된 만큼, 향후 모델링 방법의 보완을 통해 보다 한반도 전역의 정밀한 생태계 변화를 과정기반 모형을 통해 모의할 수 있도록 해야 할 것이다.

• 한국동물학회지
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• 제1권2호
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• pp.17-24
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• 1958

Since Kesser first described in 1934 the functional change of the autonomic nervous system caused by certain visible rays many researchers have unanimously approved that animals flashed with a red visible ray develop parasympathicotony while those flashed with a blue visible ray develop sympathicotony. On the other hand through studies made by our colleagues it is now well known that the inner-movement of the retinal pigments of frogs is stimulated in sympathicotony and is in reverse inhibited in parasimpathicotony. It is almost evident that the mechanism by which the inner-movement of the retinal pigments is due to sympathicotony derived from the excessive secretion of adrenalin. In addition , through may recent experiments on the pharmacological action of various medicines on the retinal pigments reaction of tadpoles , ranging from the excessive secretion of adrenalin. In addition , through my recent experiments on the pharmacologtical action of various medicines on the retinal pigments reaction of tadploes, raging from every developmental stage , Ifound that the movement of the retinal pigments by adrenalin is predominant in the earlier developmental stages of taopoles around 11 mm of body length, whereas other medicines fail to give any responce to the retinal pigments in such an earlier stage. When tadpoles grown to body length of 15-16m the retinal pigments move to the complete light position while kept in adrenalin solution. Based on these facts it might be well to consider that if tadpoles were grown under the visible rays for a given period, they might show a functional change of the autonomic nervous system and thereby cause of certain change in the physciological phases of the retinal reaction. Experiments were undertaken to find this matter and also to discover the simultaneous effects of the visible radiations on the developmental process of tadpoles. The results summarized as follows ; 1. The longest wave of visible rav has an effective reaction on the growth of body length of taopoles, while the shortest wave of visible ray causes the same for the metamorphoric differentiation of tadpoles. 2. When keeping two groups of tadpoles the first group of 15 mm body length grown for the period of one week and the latter group of 20 mm body length grown for two weeks under the various visible rays. swimming in adrenalin solution, the inner-movement of the retinal pigment occurs in both groups. The movement of pigments of the first group is accelerated in a sequence of blue ray \ulcorner green ray > brown ray> red ray, and that of the latter group is also accelerated in a sequence of blue ray>green ray > brown ray and red ray. 3. When keeping tow groups of tadpoles, the first group of 20 mm body length grown for the period of two weeks, the latter group of 25 m body length grown for three wheeks, under the various visible rays in sunlight, the inner-movement of the retinal pigments occurs in both groups. The movement of pigments of the first group is accelerated in a sequence of blue ray> green ray>brown ray and red ray, and that of the latter group is also accelerated in a sequence of blue ray > brow ray>red ray. 4. In order words, there facts manifest that tadpoles grown under the various visible rays reveal functional disturbances of the autonomic nervous system, at the time of 15 mm body length by adrenalin solution, which is a unique indicator illustrating the status of sympathicotony, and at the time of 20 mm body length by sunlight. This means that the longest visible ray cause sympathicotony, while the shortest visible ray causes parasympathicotony.

• 대한환경공학회지
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• 제22권10호
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• pp.1905-1919
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• 2000

활성슬러지 공정에 기반을 둔 연속식반응기는 시스템이 가진 고유한 비선형성뿐만 아니라 계절, 기후 등의 환경변화에 따른 유입수의 유량 및 특성 등의 외부적인 조건의 변화를 고려하여 제어하여야 한다. 수학적 모델링 과정에서 고려하지 못했거나 무시되었던 부분을 포함한 시스템에 관련된 특징과 한정된 공간에서 기본적인 제어방법에 의한 현재의 운전방법을 고려하여 불 때 활성슬러지 공정은 개선할 수 있는 여지가 많다. 또한 숙련된 운전자의 지식을 구현할 수 있는 지능제어기법을 적용하여 전체적인 공정의 효율 향상을 도모할 수 있다. 제어방법의 적용에 앞서 제어대상공정인 활성슬러지 공정을 분석하여 이를 $Matlab^{(R)}5.3/Simulink^{(R)}3.0$을 이용하여 연속식반응기 모델을 구현하였다. IWA(International Water Association)와 COST(European Cooperation in the field of Scientific and Technical Research)에서 제시한 정상상태의 유입수 특성을 이용하여 모델의 정확성을 검증하였다. 본 논문에서는 이미 현장에서 사용중인 제어기법의 구현 및 성능 평가뿐만 아니라 다양한 고급제어기법들을 적용하여 새롭게 제안한 제어기법들이 실제 폐수처리장에 적용가능한지 여부를 검증하였다. 제어방법으로는 현장에서 일반적으로 사용되고 있는 비례-적분-미분제어기(Proportional-Integral-Derivative Controller; PID controller)와 PID제어기가 가진 장점과 퍼지 논리 제어기법이 가진 장점을 결합함과 동시에 제어기의 성능 향상 및 경제성을 높일 수 있는 퍼지 PID이득 조절기(fuzzy PID gain tuner)와 퍼지 셋포인트 변환기(fuzzy setpoint changer)를 적용하여 봄으로써 외란에 대해 강인한 제어기 설계의 가능성을 검증하였다.

• 한국작물학회지
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• 제36권2호
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• pp.185-196
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• 1991

도작은 동아 습윤지 농작물의 가장 대표적인 것으로서 고금을 통하여 국가의 재정과 식량원을 조달하는 주역의 위치를 차지해 왔었다. 또한 이러한 위상은, 물론 동남아 제국을 포함하여, 중국대륙과 한반도 및 일반열도로 이어지는 지역을 중심으로 기술교류와 이해관계를 맺어오면서 형성되어 왔음에 틀림이 없다. 특히 우리나라는 지리적 위치로 인하여 더욱 두드러진 교양적 역할을 담당할 수밖에 없었고, 더우기 문화적 교체는 물론 외침과 내환을 수없이 겪는 동안 농업조건은 개간과 황폐 및 회복을 거듭하였고, 이 위에서 도작과 도작기술의 수용발전은 칠전팔기하여 왔음도 분명하다. 그럼에도 불구하고 우리나라 역사는 왕조실록을 중심으로한 조정의 기록은 풍부한 반면에 지방과 농촌의 기록은 지극히 비약한 것을 특징으로 하기 때문에 도작과 도작기술의 변천상을 알 수 있는 길 또한 지극히 제한되어 있었으며, 결국은 조선시대 초기부터 편찬되기 시작했던 농서들을 시대별로 구분하여 검토하고, 다시 종합적으로 비교고찰하면서 맥락을 더듬는 도리밖에 없다. 본 연구는 우리나라 도작기술이 여말까지 직수입 되었던 고대중국의 한전식 기술로 부터 어떻게 우리의 실정에 맞추어 성립될 수 있었고, 또한 이들로부터 독창성을 찾아 재정립된 기간은 무엇이며, 이들이 조선시대의 파란많은 내외란을 통하는 동안 어떻게 존속되고 변천해 왔으며, 이들 결과가 선말에 이르러 존속 발전하면서 치루어낸 역할이 시사하는 바가 무엇이었는지를 고찰하고자 하였다.

• 전기학회논문지
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• 제67권11호
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• pp.1423-1433
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• 2018

Recently, a permanent magnet synchronous motor of middle and small-capacity has high torque, high precision control and acceleration / deceleration characteristics. But existing control has several problems that include unpredictable disturbances and parameter changes in the high accuracy and rigidity control industry or nonlinear dynamic characteristics not considered in the driving part. In addition, in the drive method for the control of low-vibration and high-precision, the process of connecting the permanent magnet synchronous motor and the load may cause the response characteristic of the system to become very unstable, to cause vibration, and to overload the system. In order to solve these problems, various studies such as adaptive control, optimal control, robust control and artificial neural network have been actively conducted. In this paper, an incremental encoder of the permanent magnet synchronous motor is used to detect the position of the rotor. And the position of the detected rotor is used for low vibration and high precision position control. As the controller, we propose augmented state feedback control with a speed observer and first order deadbeat disturbance observer. The augmented state feedback controller performs control that the position of the rotor reaches the reference position quickly and precisely. The addition of the speed observer to this augmented state feedback controller compensates for the drop in speed response characteristics by using the previously calculated speed value for the control. The first order deadbeat disturbance observer performs control to reduce the vibration of the motor by compensating for the vibrating component or disturbance that the mechanism has. Since the deadbeat disturbance observer has a characteristic of being vulnerable to noise, it is supplemented by moving average filter method to reduce the influence of the noise. Thus, the new controller with the first order deadbeat disturbance observer can perform more robustness and precise the position control for the influence of large inertial load and natural frequency. The simulation stability and efficiency has been obtained through C language and Matlab Simulink. In addition, the experiment of actual 2.5[kW] permanent magnet synchronous motor was verified.