立地土壤의 特性

柳順昊,宋寬哲 濟州大學校 亞熱帶農業硏究所 1984 亞熱帶農業硏究 Vol.1 No.-

1975년에 完了된 濟州道 精密土壤調査 結果에 依하면 濟州道 土壤은 5 個 目, 10 個 亞目, 12개 大群, 30 個 亞群, 47 個 屬및 64 個 統으로 分類되며, 이는 便宜上 暗褐色土(17.01%), 濃暗褐色土(41.4%), 黑色土(21.6%), 및 褐色森林土(13.9%)의 4個 土壤群으로 大別된다. 濃暗褐色土, 黑色土 및 褐色森土는 代表的인 火山灰土이나 暗褐色土는 火山灰土的 特性을 弱하게 지니고 있다. 濟州道 火山灰土는 非晶質 珪酸鹽 粘土鑛物인 Allophane을 主粘土鑛物로 하고 있는데, 土壤 pH의 變化에 따라 Allophane에서 Al이 遊離되어 活性化되는 性質이 매우 强하며, 이러한 Allophane의 强한 礬土性에 基因되어 濟州道 土壤의 自然肥沃度가 낮다. 즉 難分解性의 有機物이 多量으로 集積되고, 그에 따라 假密度가 極히 낮으며 强風에 依해 土壤浸蝕이 쉽게 일어난다. 陽이온置換容量은 높으나 土壤의 鹽基吸着力이 弱하고 透水性이 過多하여 鹽基가 遊離, 溶脫되기 쉽다. 또한 燐酸을 吸着, 固定시키는 能力이 대단히 커서 有效燐酸이 缺乏되기 쉬운 問題 等이 있는데, 이러한 濟州道 火山灰土의 改良은 매우 어려운 것으로 알려져 있다. 特히 濟州道 土壤은 燐酸 固定 能力이 대단히 커서 有效燐酸이 缺乏되기 쉽기 때문에 作物 栽培에 있어서 燐酸肥料의 效果가 좋다는 것이 農民들에게 널리 알려져 Ca과 Mg 含量이 높은 熔成燐肥가 每年 多量으로 施用되어져 왔다. 따라서 濟州道에서의 肥料 施用 樣相을 調査한 結果 單位面積當 施肥量이 全國 平均에 比하여 濟州道에서 더 많을 뿐만 아니라 窒素肥料에 對한 燐酸과 加里肥料의 施用 比率도 濟州道에서 더 높은데, 이러한 傾向은 柑橘園이 많은 南濟州郡에서 더욱 현저하다. 1960年代 初부터 濟州道의 農耕地가 中山間地方으로 急激하게 增大되어가고 있으나 大部分의 農耕地는 海岸地方에 分布되어 있다. 따라서 山間地方 및 中山間地方의 土壤은 火山灰土의 一般的인 問題點을 갖고 있으나 耕作年代가 오래된 海岸地方 土壤일수록 pH, 鹽基飽和度, 有效燐酸, 置換性 Ca, Mg 및 K 含量이 높으며, 有機物 含量 및 陽이온置換容量은 낮아지는 傾向이다. 이러한 傾向은 集約的인 營農方法에 依해 經營되고 있는 柑橘園 土壤에서 더욱 현저하다. 柑橘園의 耕作年代가 오래될수록 土壤의 有效燐酸 含量 뿐만 아니라 置換性 Ca, Mg 및 K 含量이 增加하고 있으며, 陽이온置換容量은 柑橘園의 耕作年代에 따른 變化가 거의 없는데 反하여 置換性 鹽基 含量이 增加하므로 鹽基飽和度가 높아지고 따라서 pH가 높아지고 있다. 石灰나 燐酸 施用에 依해 含量 減少가 거의 없는 것으로 알려진 置換性 Al 및 活性 Al 含量은 柑橘園의 耕作年代가 오래될수록 현저하게 減少되고 있다. 置換性 Al 含量 減少는 主로 pH 增加에 基因되나 活性 Al 含量 減少는 主로 燐酸肥料의 多量 施用에 基因된다. 따라서 有效燐酸 含量이 極히 낮은 深土에서는 活性 Al이 有機物 含量 및 pH(NaF)와 高度로 有意한 상관관계가 있으나 表土에서는 상관이 낮다. Cheju Do is a volcanic Island. The valcanic eruptions began in the tertiary and the last eruptions were in 1002 and 1007 A.D. Volcanic ash is wide spread as soil parent material throughout the Island. Soils in the Island thus reveal typical characteristics of volcanic ash soil. The soils in Cheju Island are classified into 5 orders, 10 suborders, 12 great groups, 30 subgroups, 47 families and 64 series. For convenience, however, these soils are categorized mainly into 4 groups : dark brown soils(17.0%), very dark brown soils(41.4%), black soils(21.6%) and brown forest soils(13.9%), The last two groups have typical characteristics of volcanic ash soils, while the first is atypical. It is well known to farmers that soils in the Island have very high phosphate fixing capacity. Heavy application of phosphate and potassium fertilizer is a common practice. Therfore the amount of chemical fertilizers consumed per unit area of cultivated land and the ratios of ?? and K₂O to N in Chemical fertilizers applied are much higher in the Cheju Island than those of the Korean mainland. These trends are particularly prominant in Southern Cheju where 70% of the Cheju citrus orchards are located. The coastal area has long been used for intensive farming and some of the midmountain region were recently reclaimed for agricultural crop production. The cation exchange capacity and the organic matter in the soils increase in the order of coastal area mid-mountain belt upper mountain area, while pH, base saturation, available phosphorus and exchangeable bases decrease with the elevation. These trends are especially prominant in citrus orchard soils. As the result of heavy application of phosphate fertilizers, the available phosphorus of citrus orchard soils increase with increasing number of years of cultivation. Base saturation and pH increase with the increase in number of years of cultivation, inasmuch as exchangeable bases such as Ca, Mg and K increase prominantly, but the cation exchange capacity do not vary in the citrus orchard soils. The exchangeable Al of the citrus orchard soils decrease with increasing number of years of cultivation. This has resulted from an increase in pH. The content of the extractable Al of the citrus orchard soils also decrease with the increase in number of years of cultivation. This is related to the fact that application of phosphate fertilizers led to a reduction in Al activity. The extractable Al content strongly correlated with the organic matter and pH(NaF) in the sub-soil where the available phosphorus is extremely low, but the correlation is less significant in the top soil. This suggests the large amounts of the extractable Al are released from the hydrous oxides of Al and that the organically complexed form in the sub-soil, and non-extractable due to the reactions with phosphates applied to the top soil.

문제 중심 학습법 수행을 위한 컴퓨터 프로그램 개발

유선미,이진형 단국대학교 1998 論文集 Vol.33 No.-

Medicine in the twenty-first century will be different from the medicine of today. Recent changes in medical environment, such as changes in disease and mortality pattern and rapid increase in medical knowledge, require change and adaptation of medical education. The task of medical education is to help people entering medicnie to prepare to meet their professional obligations in this new context. So we tried to join Problem-base learning(PBL), which challenges students to be more actively involved in defining what they learn and how they learn, and Computer-assisted learning(CAL), which uses multimedia and medical informatics as learning tools. Finally we developed Problem-oriented medical education program using the Internet. First, using simulated patient cases, we built clinical database with patients’ history, physical examinations, and various laboratory findings. To provide PBL program through the Internet, we constructed client-server system using IIS(Internet Information Server) on Windows-NT settings, and made user-friendly dynamic interface with HTML, JAVA, JAVE Script and so on. PBL on the WEB will make students learn effectively and actively, and offer vivid multimedia environment for medical education. We expect this PBL program to be used as an effective learning tool for residents or doctors as well as for medical students in the near future.

인터넷-PSTN 연동 게이트웨이 신호 프로토콜 검증

유상신,이순흠 순천향대학교 부설 산업기술연구소 1999 순천향 산업기술연구소논문집 Vol.5 No.1

In this paper, we study on the interoperability between the traditional telephone, connected to the circuit-switched networks, and the internet phone, connected to the Internet, respectively. Especially, we focus on the necessity and possibility of interoperability, and furthermore derives the necessary requirements of interoperability. For this purpose, we analyze both ISDN and Internet signalling system, that are closely related with the interworking. We also investigate the basic call processing parts of each system using the state transition diagrams and the signalling procedures. Then, we model the signalling protocol for gateway systems using the Petri-Net model. Through reachability trees of the Petri-Net model, we confirm that interoperability is possible, and that characteristics of deadlock, liveness, and boundness are satisfied. Finally, we describe the design of interworking function that converts the differences of two signalling systems.

最適 組織構造의 說計를 위한 進路의 探索 : 官僚制의 向方과 관련하여 With Reference to the Future Prospect of Bureaucracies

柳錫永,曺善一 건국대학교 1985 論文集 Vol.21 No.1

The statement that organization structures facilitate the achievement of organizational goals assumes that managers know how to match organizational structures and goals and that they desire to do so. A number of characteristies of organizational structure not only describe the organization, but also lave implications for the behavior of individuals and groups as well as the organization itself. When the organization is the focus of attention we are concerned with its adaptiveness, flexibility, growth, and development. What is appropriate organization design which enable it to meet and respond to economic, political, and social pressures for change and development? Bureaucracy, orginated from the work of German sociologist Max Weber, is both the dominant organizational forts: in society and it has achieved it's distinction because it works best with the type of technologies and enviroments that most organizations have. But M. Weber's bureaucracy is attacked for incuring it's dysfunctional consequences and operating in stable enviroment where contingencies can be predicted. Against these machine bureaucracy views, there is a second type that is more effective with highly skilled employees. This structure, which relies on extensive decentralization, is called a professional bureaucracy. It typically appears in organizations that confront enviroments that are both complex and stable. Meanwhile, there are counterarguments for the coming death of bureaucracy. Warren G. Bennis argued that the bureaucratic structure is too mechanical to meeting for needs of modern enviromental situations. Therefore he forecast that in the most 25 to 50 years we would participate in the end of bureaucracy as we know at and in the rise of new social systems better suited to the 20th century demands of industrialization. There is, however, strong opposite view for it. R. Miewald, for example, has argued that bureaucracy can adapt to changing dynamic enviroments. These positions which reflect two perspectives on bureaucracy, probably seems to be depend on contingency conditions or situational logics. Recent several studies have shown that the form of an organi2ation does make a difference in organizational effectiveness. Some forms of organization, for example, are more effective under certain conditions, but other forms of organizations work better under different conditions. This is key expression of contingency approaches to organization. This approaches is concerned the organization as a unit in interaction with its enviroment. In this approach, the organization is considered as a complex set of interdependent parts interacting with one another and dependent in whole on some larger enviroment. In this above view, ad-hocracy which has been described a rapidly changing, adaptive, temporary system organized around diverse professional skills, would be characterized as having moderate to low complexity, low formalization, and decentralized decision-making. The most popular applications of ad-hocracy is the matrix structure and three further examples of ad-hocracies are the task force, the committee structure, and the collegial structure. These types of designs should be considered with diverse, changing, or high-risk strategies or where the technology is nonroutine and the enviroment is both dynamic and complex. We should be also noticed that there is the possibility of using both types of structure in the same organization because terms "bureaucratic" and "nonbureaucratic" are only crude extremes. An example of the search for this possibility is Charles Perrow's the Mixed Model. In sum, the logic of determination for the optimal organizational structure is that it can be begin selectively to apply the multitude of insights offered by organization analysis and depend on the design parameters and contingency factors such as task, age, size, and enviroment etc.

甫吉島의 孤山遺蹟과 漁父四時詞의 背景試論

柳玗善 全南大學校 湖南文化硏究所 1977 호남학 Vol.9 No.-

버퍼 수준 제어를 통한 동기화 회의 시스템

유상신,이순흠 순천향대학교 부설 산업기술연구소 1999 순천향 산업기술연구소논문집 Vol.5 No.1

In this paper, we study on a synchronized conferencing system which provides both intra-media and inter-media synchronization function using the synchronization controller. The synchronization controller provides lip-synchronization between audio and video signals using the buffering-level adaptation.

원격 영상 정보 시스템의 개발

김선호,유선국,김용구,박성욱,김성림,김남현 대한의료정보학회 1996 Healthcare Informatics Research Vol.2 No.1

중이기형을 동반한 안이척수이형성 증후군에서 시행한 난원창 개창술 1예

조양선,정유석,이종찬,추광철 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.12

고등학교 일반수학 교과서의 오류분석

유윤재,이순이 慶北大學校 師範大學 1992 敎育硏究誌 Vol.34 No.-

The purpose of the paper is to analyze the various fallacies of the current textbooks of high school mathematics. The scopes of the research consist of terminologies, editorial problems, and logical errors. By comparing with textbooks, it was found that mathematical teminologies are used differently. The reason why this problem happens is that the Ministry of Education has not unified the terminogies more concretely. Some textbooks do not explain some definitions clearly and the authors proposed some remedies to overcome these problems.

특이섭동 시스템의 적응제어 및 시뮬레이션

유선국,허명준 순천향대학교 1991 논문집 Vol.14 No.3

The pseudo-plant contains a model whose order is determined by the controller order. The given plant is identified by a higher order identifier, and then reduced to the controller order by means of the singular perturbation concept. The plant, the chosen model, and a filter constitute the pseudo-plant. For the implementation of the adaptive controller, a design guideline of the filter is proposed. As the plant model is chosen by a reliable procedure, choosing the filter to have the same frequency characteristics of the chosen model might be a good policy. Simulation results show the effectiveness fo proposed method.