http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
비정형구조물의 초기대안 설계를 위한 L-system 모델 적용 방안
The structural and design parts should be considered because the free-formed structures have the unformal and irregular shapes. Especially, the initial design for the free-formed structures should be performed through the various structural shape creation. To this end, this study creates the structural shape of free-formed structures using the biological algorithm for L-system model of morphogenesis technique. L-system model can generate the various shapes by the substitution of word and meaning and has the advantage of simple rule and easy programming. Also, the free-formed structural shapes are classified as the internal and external patterns with the connection method, and the various structural shape are created by applying the parameters through the assumption of joint coordinates for the final string arrays.
Purpose: Bisphosphonates(BPs) suppress osteoclast-mediated bone remodeling & bone turnover. Bone marrow stem cells(BMSCs) can differentiate into multiple cell types (e.g. pre-osteoblast, osteoblast). Because BMSCs express RANKL on their cell surface, they also indirectly modulate osteoblast-osteoclast balance. It is the purpose of this study to examine the effects of BPs (Alendronate, Pamidronate) on expression of macrophage colony-stimulating factor(M-CSF) and osteoprogesterin(OPG) during the process of osteogenic differentiation in normal human mesenchymal stem cell into osteoblast. Materials & Methods: 1) Cell culture & cellular proliferation: the cells were cultured in osteogenic induction medium together with 0(control group) and 10-8 M Alendronate, Pamidronate for up 2 & 3 weeks (for real-time PCR) and 3 & 4 weeks (for ELISA). 2) Real-time PCR : The PCR assyas were performed on a Mini opticon (BIO RAD, USA). The PCR protocol for M-CSF, OPG and glyceraldehyde 3-phosphate dehydrogenase(GAPDH) consist of 40 cycles (FINNZYMES, Finland). 3) Enzyme-linked immunosorbent assay (ELISA) : The amounts of M-CSF and OPG in the culture medium were determined using commercially available ELISA kits for M-CSF(R&D system, USA) and OPG (Apotech, Switzerland), according to the manufacturer’s instructions Results: 1) Real-time PCR: The gene expression level for M-CSF after 2 and 3 weeks of culture were suppressed by alendronate & pamidronate, but these rates continue to increase as time passed (2week→3weeks). An increasing rate of alendronate group is higher than pamidronate group. The gene expression level for OPG on 2 weeks of culture were suppressed, but 3 weeks of culture were accelerated by alendronate & pamidronate, but these rates continue to increase as time passed(2week→3weeks). An increasing rate of alendronate group is higher than pamidronate group. 2) Enzyme-linked immunosorbent assay(ELISA): The mean of optical density(OD) of all groups continue to increase as time passed(3weeks →4weeks).The protein expression level for M-CSF after 3 weeks & 4 weeks of culture were suppressed by alendronate & pamidronate. In comparison among all groups, each of groups is mutually statistically significant(p<0.05), but there was no significant difference between alendronate and pamidronate group are within 3 weeks group. The mean of optical density(OD) of all groups continue to increase as time passed (3weeks →4weeks).The protein expression level for OPG after 3 weeks of culture were suppressed by alendronate & pamidronate, but level of 4 weeks of culture were accelerated by alendronate & pamidronate. In comparison among all groups, each of groups is mutually statistically significant(p<0.05). 4. Conclusion: 1. Both alendronate and pamidronate suppress gene & protein expression of M-CSF. 2. Both alendronate and pamidronate accelerate gene & protein expression of OPG. 3. In aspects of the effect of bisphosphonate on M-CSF, pamidronate have much specific effect than alendronate. 4. In aspects of the effect of bisphosphonates on OPG, alendronate have much specofoc effect than pamidronate. Therefore, we need further evalution about effects of bisphosphonates on osteoblast and osteoclast-osteoblast interaction. Key words: Bisphosphonates(BPs), BMSC, M-CSF, OPG
Baseline Modulation Scheme for ECG Detection Performance Improvement in Wireless Body Area Network
Electrocardiogram (ECG) representing the electrical activity of the heart is the important bio signal for aiding the clinical staff in heart disease diagnosis. However, the elements of ECG are distorted and the probability of ECG detection declines due to a variety of noise and interference. Therefore, in this paper, we proposed and analyzed the ECG detection algorithm based on Pan-Tompkins algorithm by employing the ECG monitoring system in wireless body area network. Firstly before ECG features are detected, baseline modulation accurately removed baseline drift, and the median bandpass filter efficiently preprocessed the ECG signal to reduce noise and interference. After pre-processing, this algorithm carries out to reliably detect QRS complex using slope, amplitude, and width information. Finally, the ECG features are extracted and marked. We simulated the proposed algorithm using the recordings of the ECG signal are provided by MIT-BIH Arrhythmia Database in ‘Matlab 7.10.’ The proposed algorithm offers sensitivity of 99.79 %, positive prediction of 99.67 % and detection error of 0.0054. 본 논문은 wireless body area 네트워크 기반 ECG monitoring system에서 ECG 검출 알고리즘에 대해 연구하였다. ECG는 심장질환의 조기진단을 위해 사용되는 심장의 전기적 활동을 나타낸 중요한 생체신호이다. 그러나 임상 환경에서의 다양한 노이즈로 인한 ECG 신호의 왜곡되고, 이러한 ECG 신호는 정확하게 검출하지 못하는 문제점이 있다. 따라서, 본 논문에서는 wireless body area네트워크 기반 ECG monitoring system에서 이러한 문제점을 해결하고 ECG 신호의 정확한 검출을 위해 Pan-Tompkins 알고리즘을 기반으로 ECG 검출 알고리즘을 제안하였다. 본 논문의 실험 결과를 통하여 ECG신호가 효율적으로 검출됨과 높은 검출 성능을 보였으며, 본 논문에서 제안한 알고리즘을 통하여, ECG신호를 왜곡하는 다양한 노이즈를 효율적으로 제거할 수 있는 방법을 제시하였다. 또한, 본 논문의 연구를 통하여 앞으로의 wireless body area network 기반 ECG monitoring system에서 ECG 신호를 효율적으로 검출할 수 있는 방안에 대한 연구를 수행하는데 있어 응용 가능하다.
Effects of acupuncture on stress response in a rat model of post-traumatic stress disorder
Post-traumatic stress disorder (PTSD) is a psychiatric disease followed by an exposure to traumatic events. PTSD symptoms cause significant problems in social or work situations and in relationships. But, there is no obvious drug treatment for PTSD, although antidepressant and psychological approaches show partial alleviation. Acupuncture is one of the traditional Korean medicine therapeutic modalities that is known to be effective for treating mental disorders. Acupuncture has shown beneficial effects in PTSD patients, however, the underlying mechanisms therein remain uncertain. Therefore, we investigated whether acupuncture has beneficial effects on the PTSD model and its underlying mechanism. First, we explored the antidepressant and anxiolytic effects of acupuncture at acupoint HT8 using forced swimming test, open field test, and elevated plus maze test in single prolonged stress (SPS) model of PTSD. To elucidate the associated mechanism with effects of acupuncture, the involvement of mTOR signaling pathway, which contributes to protein synthesis required for synaptic plasticity in the hippocampus, was observed using western blot analysis. The mediation of mTOR pathway in the acupuncture effects was tested using the challenge of mTOR inhibitor rapamycin. In the result, acupuncture at HT8 significantly alleviated both depression- and anxiety- like behaviors induced by SPS in the forced swimming, elevated plus maze, and open field tests. Effects of acupuncture are similar to those of antidepressant drug, fluoxetine. Moreover, acupuncture regulated the levels of protein translation in mTOR signaling pathway and enhanced the activation of postsynaptic protein, PSD95 in the hippocampus. Additionally, rapamycin blocked the effects of acupuncture, indicating the involvement of mTOR signaling pathway. In conclusion, based on these results, acupuncture at HT8 has antidepressant and anxiolytic effects on the PTSD-related symptoms by increasing synaptic plasticity via activating mTOR signaling pathway in the hippocampus. Therefore, we suggest that acupuncture may be helpful for PTSD patients and play a potential role as an alternative PTSD treatment intervention in relation to the mTOR signaling pathway. 외상 후 스트레스 장애는 심각한 사건을 경험한 후 그 사건에 공포감을 느끼고 사건 후에도 계속적인 재경험을 통해 고통을 느끼며 거기서 벗어나기 위해 에너지를 소비하게 되는 질환으로, 불안증과 우울증을 동시에 겪게 된다. 현재 외상 후 스트레스 장애의 치료는 심리치료와 약물치료로 이루어지고 있지만, 많은 부작용과 한계가 있어 다른 치료법이 필요하다. 침 치료는 다양한 질환을 치료하기 위한 효과적인 치료법으로 사용되고 있으며, 부작용이 없는 대표적인 치료법이나 현재까지 외상 후 스트레스 장애와 침 치료에 관한 연구는 없었다. 본 연구는 외상 후 스트레스 장애에서 침 치료를 할 때 어떤 혈자리가 가장 효과가 있는지 조사하고, 행동실험을 통해 그 혈자리가 불안증세와 우울증세를 개선시켜주는지, 어떤 인자들이 연관성이 있는지 밝히고자 하였다. 먼저, SD 랫에 일회성의 지속적인 스트레스로 외상 후 스트레스 장애를 유발한 후, 신문과 소부 혈자리에 자침하여 행동변화를 관찰한 결과 소부혈이 외상 후 스트레스 장애 동물 모델에 적합한 혈자리인 것으로 보였다. 두 번째로, 외상 후 스트레스 장애를 유발하여 소부혈과 비경혈에 자침한 것과, 항우울제인 플루옥세틴과 비교하였다. 소부혈 침 치료는 플루옥세틴과 비슷한 수준의 효과를 보였다. 그리고 침 치료 후 변화하는 인자를 규명하기 위하여, 포유류라파마이신표적(mTOR)의 기전과 관련된 단백질의 변화를 뇌의 해마에서 관찰하였다. 그 결과, 침 치료 후에 mTOR기전의 상위 단백질과 하위 단백질 그리고 신경성장인자가 모두 유의한 변화를 보였으며 시냅스 가소성이 발생하였다. 또한, mTOR의 억제제인 라파마이신을 비강주입 하였을 때 침 효과가 차단되는 것을 확인하였다. 결과를 종합하면, 일회성의 지속적인 스트레스로 외상 후 스트레스 장애를 유발한 동물 모델에서 소부혈에 자침으로 인하여 불안증세와 우울증세가 개선된다는 것을 알 수 있으며, 또한 mTOR 기전의 발현과 시냅스가소성에도 관계된다는 것을 알 수 있었다.
Background: Parkinson’s disease (PD) is a multi-layered progressive disease with characteristic motor dysfunction and a variety of other symptoms such as cognitive impairment. Although acupuncture has been used to treat various ameliorating neurodegenerative disorders, including PD and dementia, its underlying mechanism, especially in relation to the simultaneous control of multiple symptoms, is unclear. It has been previously revealed that melanin-concentrating hormone (MCH, encoded by pMCH) is responsible for the acupuncture effect on PD. However, it is unclear how MCH neurons, specifically localized in the lateral hypothalamus (LH), are involved in the acupuncture mechanism. Therefore, we investigated whether acupuncture improves motor dysfunction and cognitive deficits via an MCH-mediated neural circuit in the LH. Methods: We utilized DREADD to chemogenetically activate or inhibit the activity of pMCHLH neurons in a PD mouse model. C57BL/6 mice were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to induce PD, and acupuncture was applied at GB34 acupoint. Rotarod, cylinder and open field tests were performed to measure the motor deficit of PD mice, and Y maze and novel object recognition test were performed to measure cognitive function. Results: Activation of pMCHLH neurons mimicked the therapeutic effects of acupuncture in terms of the motor and cognitive impairments. Conversely, inhibition of pMCHLH neurons blocked the therapeutic effects of acupuncture for motor and cognitive impairment. Among them, pMCHLH neurons projected to the substantia nigra pars compacta (SNpc) and hippocampus (Hipp) specifically regulated motor and cognitive symptoms, respectively, for the acupuncture effect. Conclusions: These results provided evidence that discrete but interconnected pMCHLH neural circuits are the key mechanism for the differential alleviation of motor and cognitive symptoms by acupuncture in a PD mouse model. This study demonstrates a novel circuit-level mechanism through MCHLH neurons to the SNpc and Hipp, suggesting that acupuncture treatment can stimulate these MCH neurons and be a therapeutic strategy for PD.
국문초록 세례예전의 사중복음적 이해 서울신학대학교 신학전문대학원 실천신학전공 오 주 영 2007년을 기점으로 기독교대한성결교회는 100년의 역사를 품은 교단이 되었다. 한반도에서 개신교 선교는 약 120년 전에 시작되었기 때문에, 한국적 정서에서 기독교 교단이 지속적으로 발전하고 교단의 교회들이 확장되는 것은 매우 중요한 의미를 지닌다. 지난 100년 동안 기독교대한성결교회는 사회-정치적 논쟁뿐만 아니라 신학-교리적 논쟁 또한 직면해왔다. 그러나 기독교대한성결교회는 교회 내외적인 모든 어려움을 극복하고 존 웨슬리의 신학과 19세기 미국성결운동에 따른 교단 신학적 관점을 만들어왔다. 그에 따라 기독교대한성결교회는 한국 기독교 세 개의 중요한 개신교 교단 중 하나로 인정받게 되었다. 특별히, 최근 교단 100주년을 기점으로 성결교회신학연구위원회에서는 교단신학의 정체성을 밝히기 위해 노력하고, 다른 현대 신학 그룹들과 사회-문화적 변화와의 대화를 형성하고 있다. 본 연구는 기독교대한성결교회의 이러한 신학적 동향과 세례예전의 안에 있는 기독교대한성결교회의 사중복음적 요소에 주목함으로 고무시키는 것이다. 본 논문에서, 이러한 연구는 세례예전 안에 있는 중생, 성결, 신유, 재림이라는 기독교대한성결교회 사중복음의 교리적 해석에 일조한다. 따라서 본 연구는 세례예전의 바탕 위에서 사중복음 신학과 정통 기독교의 일반적 전통 사이의 대화에 집중한다. 그러나 이 연구는 부활절 성인 세례예전 기초한 제한된 범주로 제한한다. 세례예전의 전통적, 정통적 관점을 조사하기 위하여, 본 연구는 성서시대, 사도시대, 초대교회, 종교개혁시대, 존 웨슬리, 19세기 마국 복음주의 운동, 만국성결연합, 동양선교회의 신학에 초첨을 맞추었다. 그리고나서 기독교대한성결교회 세례예전의 구체적인 이해를 위해, 기독교대한성결교회와 사중복음의 교단 신학을 수립하고 개발하는데 선도적인 역할을 했던 이명직 목사의 개신교 복음주의 신학을 조사하였다. 이 연구는 조사를 위한 주요 방법론으로서 김중기의 구조적인 분석을 강조한다. 이러한 구조적인 분석은 사중복음 신학의 네 가지 요소(중생, 성결, 신유 그리고 재림)의 교리적 이해와 사중복음 신학의 체계적인 역사적 형성과정의 설명을 돕는다. 이러한 구조적 분석에 의해서 해석된 사중복음 신학의 예비된 이해를 통하여, 사중복음 신학이 개신교 복음주의 신학 이해를 위해 적확하게 준비되었다는 것을 동의할 수 있을 것이다. 더 나아가 나의 신학적 방법론은 기독교대한성결교회 신학자들의 최근 연구에 의해서 떠오르고 있는 사중복음 신학의 전통적인 이해를 위한 새로운 해석을 보여주고, 정통 기독교의 보편적 중요성과 개신교 복음주의 신학이라는 것을 밝혀준다. 세례예전과 관련해서, 적절한 사중복음의 구조적 분석은 세례교육과정, 수세, 견신례, 첫 성만찬과 같은 모든 세례예전의 요소들의 신학적 이해와 세례예전 요소들의 이해와 역사적 형성과정을 설명한다. 더 나아가 구조론적 분석은 이 네 가지 단계(세례교육과정, 수세, 견신례, 그리고 첫 성만찬)의 온전한 거행을 통하여 세례예전에 대한 통합적인 사고가 완성될 수 있다는 것을 보여준다. 특별히 사중복음 신학에서 네 개의 신학적 표어(중생, 성결, 신유, 그리고 재림)와 조우할 수 있고 세례예전의 이러한 네 개의 단계들이 신학적으로 의미 있게 만날 수 있으며 지평의 융합으로 발전할 수 있다. 본 연구는 그 형성과정에 따라 세례예전은 성서시대부터 기독교대한성결교회에 이르기까지 전체 과정을 살펴보았다. 특별히 성서와 초대교회 세례예전의 통합적 이해를 표본으로 삼고, 이후 중세와 종교개혁 그리고 오늘날에 이르기까지 통합적인 세례예전에 대한 이해의 부족으로 기독교 역사상 세례예전이 거행되지 않은 적은 없지만, 종교개혁자들에 의해 지나치게 그 표징행동이 삭제되고 단순화되어 이제는 세례예전을 통해서 전해지던 비가시적인 삼위 하나님의 은혜가 가시적으로 전달되는 과정이 파행되고 있다는 것을 밝혔다. 또한 사중복음은 그 형성과정에 따라 존 웨슬리, 만국성결연합, 동양선교회, 그리고 초기 성결교회를 거치면서 형성된 교의적 신학이 오늘날 기독교대한성결교회 안에서 어떻게 보편 가치로 확대 재해석되고 있는지를 밝혔다. 본 연구에 따르면 하나님의 은혜는 비가시적인 것이다. 이것을 가시적으로 드러내는 하나님의 은혜의 수단(means of God)은 두 가지로 나타난다. 하나는 사중복음으로서 ‘표징말씀’(sign-words)이고 다른 하나는 세례예전으로서 ‘표징행동’(sign-acts)이다. 이 두 가지 은혜의 수단은 모두 삼위 하나님의 역사하심에 근거하며 삼위 하나님의 은혜를 가리키고 있다. 성서와 초대교회 안에서는 이 두 가지가 상보적인 관계로 세례예전에 참여하는 사람들의 믿음과 은혜를 극대화시킨다. 그러나 앞서 언급했던 것처럼, 이러한 귀중한 예전적 전통들이 중세를 거치면서 오늘날까지 왜곡의 길을 걷고 있는 것이다. 특별히 개신교 안에서는 그 동안 세례 ABSTRACT Understanding of the Fourfold Gospel Theology Implied in the Baptismal Sacrament Oh, Ju Young Doctor of Theology in Practical Theology Graduate School of Theology Seoul Theological University Bucheon, South Korea Supervised by Professor Cho, Ki Yeon (Ph.D.) In 2007, the Korean Evangelical Holiness Church (KEHC) celebrated its 100th anniversary. In the Korean context, there is a very important meaning for a Christian denomination to continually develop and expand its denominational churches because the protestant mission at Korean peninsula started roughly 120 years ago. In the past 100 years the KEHC has confronted not only socio-political controversies but also theological-doctrinal disputes. However, the KEHC has overcome all difficulties inside and outside the Church and produced KEHC's own theological perspective based on the theology of John Wesley and the 19th century American holiness movement and been finally recognized as one of three important protestant denominations in Korean Christianity. Specifically, the committee of the theological study in the KEHC has been attempting to investigate the theological identity of the KEHC and forming a dialogue with other modern theological groups and socio-cultural changes. This dissertation is encouraged by this theological movement within the KEHC and particularly pays attention to the perspective of the KEHC's the Fourfold Gospel theology implied in the baptismal sacrament. This study strives to interpret the doctrine of the perspective of the Fourfold Gospel Theology: regeneration, sanctification, divine healing, and the second coming in KEHC in terms of the baptismal sacrament. In other words, this study focuses on the baptismal sacrament dialogue between the particular perspective of the Fourfold Gospel Theology and the general tradition of Christian Orthodoxy. However, this study has a limitation to narrow down a theme within the adult baptismal sacrament based on the Easter. In order to investigate the traditional and orthodox perspective of the baptismal sacrament, this study, to begin with, pays attention to the biblical era, the apostolic age, the early church, the reformation period, the theology of John Wesley, the 19th century American evangelical movement, the International Holiness Union, and the Oriental Missionary Society(currently, One Mission Society). Then, for the specific understanding of the baptismal sacrament in the KEHC, I would examine the protestant evangelical theology of Rev. Myeong Jik Lee who had played a leading role of establishing and developing the KEHC and its theology, the Fourfold Gospel Theology. This study employs the structural analysis of Kim Jung-Ki as the main methodology. This structural analysis helps to understand the doctrinal meaning of four elements in the Fourfold Gospel Theology (regeneration, sanctification, divine healing, and the second coming) and to explain the historical process of formulating this Fourfold Gospel Theology. Through this preliminary understanding of the Fourfold Gospel Theology interpreted by the structural analysis, it can be agreed that the Fourfold Gospel Theology prepares to fully understand the Protestant evangelical theology. Moreover, my theological methodology reveals that a new hermeneutics for the traditional understanding of the Fourfold Gospel Theology, raised by a recent group study of the KEHC's theologians and uncovers the universal significance of the Christian orthodoxy and the protestant evangelical theology. Hence, the theological particularity of the Fourfold Gospel Theology has a close doctrinal connection with the universality of the Protestant evangelical tradition. In relation to the baptismal sacrament, the structural analysis of the Fourfold Gospel Theology properly explains the theological understanding of every baptismal sacramental element such as catechumenate, water baptism, confirmation, the first Eucharist, and the historical process of constituting the baptismal sacramental elements. Moreover, the structural analysis structurally shows that the ideal synthesis of the baptismal sacrament can be completed, through fully practicing these four steps (catechumenate, water baptism, confirmation, and the first Eucharist). Specifically, the encounter of the four theological catchwords (regeneration, sanctification, divine healing, and the second coming) in the Fourfold Gospel Theology and these four steps in the baptismal sacrament can be a theologically meaningful event and can be developed into a convergence of horizon. This study reviews the whole developmental process of the baptismal sacrament from the biblical era to the KEHC. Based on the synthesizing view of the integral baptismal sacrament in the early church era, this dissertation reports that although the baptism sacrament and never disappeared in the history of Christian liturgy and since the reformation era, the significance of the baptism sacrament had been simplified and limited and finally in contemporary era, the invisible grace of the trinitarian God mediated by the baptismal sacrament is totally distorted and disregarded. This study also sheds a light on the universal significance of the Fourfold Gospel Theology. With regard to the theological origin, the Fourfold Gospel Theology has been doctrinally constructed on the basis of the theology of John Wesley, the International Holiness Union, the Oriental Missionary Society, and the early Holiness Church. The Korean Evangelical Holiness Church strives to reinterpret the theological particularity of the Fourfold Gospel Theology as connecting it with the universality of the Christian evangelical orthodoxy. This study claims that the grace of God is essentially invisible. The means of God's grace in which the grace of God becomes visible, however, appears as two types: one is the sign-words as the Fourfold Gospel and the other is the sign-acts as baptismal sacrament. Both types about mean
오주영 고려대학교 교육대학원 2008 국내석사
The purpose of this study is to investigate the appropriateness of textbooks and methodologies in elementary English private education and to make suggestions in its development. In this study, three popular and distinctive franchise institutions were chosen and analyzed; two institutions(A, B) with its own textbooks(A', B'), and the other(C) with its imported textbooks(C'). Setting the analysis criteria on the basis of Skierso' and Tucker's textbook checklists, this study focuses largely on four areas; organization system, content(i.e. subject matter, language function & activities, and communicative function), language materials(i.e. vocabulary, pronunciation, and grammar), and teaching method. To lend objective support to the analysis, analysis survey was conducted with 32 specialists in English education field. The results of the analysis are made as follows: 1. Level-specific curriculum and utilization of multimedia are distinct merits of A. B individualizes learning but should consider significance of interaction. Appropriate distribution of class time should be considered especially with young learners. 2. Generally, introduction of the culture is lacking. A' and B' include subject matters that are more familiar and appropriate to our culture than C'. 3. Language function should be balanced, providing enough input first. A' and B' need to provide more authentic speaking opportunities rather than writing practices. 4. Practical communicative functions such as checking comprehension, asking expressions, expressing negative feelings, etc. should be included. Not only conversation between two people, but also real-life communicative situations should be reflected. 5. Vocabularies in A' and B' are highly repetitive, whereas C' presents a variety of vocabularies. Adequate balancing of the repetitiveness and variousness and also presenting it within the context is important. Readability should be adjusted according to each level. 6. With phonics, enough information should be given for EFL students but in a simple, understandable way. Aural presentation and picture images are recommendable as to facilitate children's first learning. 7. With grammar books, B' presents grammatical information in a structural way whereas A' focuses more on the analysis and explanations on forms. C' lacks in providing enough information but has various, authentic activities. 8. A and B's teaching methods took EFL learners into consideration. A's thought unit can help greater understanding of sentences by meaningful phrases. However, it is limited in that it prevents from thinking in target language and it is not applicable for certain patterned expressions. B is based on systematic approach focusing on the difference between Korean and English. It effectively presents basic principles in sentence constructions using charts to show the structure. C's communicative approach and its integrated attempts could be effective when it considers EFL teaching circumstances in a realistic sense. The study suggests that characteristics and situations of EFL elementary learners should be greatly considered in developing the textbook and methodology. Furthermore, continual monitoring of the private English education and evaluating its effectiveness is needed.
로더는 버켓을 이용하여 건설 현장에서 토사를 상차하거나 운반 작업을 주목적으로 수행하는 건설 기계이며, 바퀴로 구동되는 휠로더가 보편적으로 사용되고 있다. 휠로더용 자동변속기는 건설 작업의 특성 상, 열악한 환경에서 장비가 운용되므로 변속 성능은 주요 연구 대상이 아니었다. 그러나 제어 기술의 발달과 운전자의 편의성 증대에 대한 요구로 인해 자동변속기의 변속 성능 개선에 관한 연구가 중요한 사안으로 대두되고 있다. 본 연구에서는 자동변속기를 장착한 휠로더 동력전달계의 해석 모델을 구성하여 자동변속기의 변속 성능을 해석하였다. 특히, 동력전달계는 엔진, 토크컨버터, 자동변속기, 차축 및 주행 부하로 구분하여 모델을 구성하였으며, 해석 대상인 자동변속기는 기어열, 클러치팩, 유압 시스템 및 변속제어 시스템으로 구분하여 상세한 모델을 구축하였다. 또한, 휠로더 자동변속기의 유압 시스템은 클러치 피스톤의 작동 압력을 직접적으로 제어하는 직접 제어 방식을 적용하였다. 동력전달계 해석 모델의 시뮬레이션 결과를 실차 실험 결과와 비교하여 해석 모델의 타당성을 검증하였으며, 검증된 모델을 이용하여 자동변속기의 변속 특성을 분석하였다. 변속 성능은 클러치 내부의 압력에 종속적이므로, 변속기 클러치 압력 조작용 비례 압력 제어 밸브의 전류 프로파일의 궤적을 변경시켜 가며 시뮬레이션을 수행하였다. 시뮬레이션에서 전류 프로파일은 급속 충전 영역, 테이크 오버 및 클러치 슬립 영역, 클러치 슬립 시간으로 구분하여 변속 성능을 분석하였다. 또한, 클러치 전달 토크 용량을 일정하게 유지한 상태에서 변속 성능에 영향을 미치는 설계 파라미터를 클러치 플레이트 마찰계수, 클러치 플레이트 지름 및 클러치 플레이트 개수로 선정하여 파라미터 변화에 대한 영향을 시뮬레이션을 통해 분석하였다. 특히, 변속 성능을 정형화하여 판단하기 위해서 저크의 상대적인 크기를 이용하였으며, 선정된 설계 변수가 변속 성능에 미치는 영향을 분석하였다. 마지막으로 변속 성능을 개선하기 위하여 저크가 작은 터빈 속도를 선정하여, 그 속도를 추종하도록 전류 프로파일을 제어하는 피드백 알고리즘을 적용하여 변속 성능이 개선됨을 확인하였다. A loader is a construction machine to upload soil and sand into trucks or to transport those materials. As a kind of loaders, a wheel-loader, which is driven by wheels, has been widely used. Since a wheel-loader with an automatic transmission operates in the adverse environments such as constructions sites, the shift quality has not been addressed as a main research topic. However, the necessary for researches to improve the shift quality of automatic transmission raised to develop control technology and to enhance operator’s convenience. In this study, a wheel-loader’s power train with an automatic transmission was analytically modeled and then the shift quality was analyzed based on power train modeling. For modeling, the sub-components of a wheel-loader’s power train were modeled, which were an engine, an automatic transmission, torque converter, axles and vehicle loads. Particularly, detailed modeling of the automatic transmission was carried out according to its subdivided parts such as the gear train, clutch-pack, hydraulic system and transmission control unit. In addition, a direct control method was applied to the hydraulic system of the wheel-loader’s automatic transmission in order to control pressure in clutch piston directly. An analytical model of wheel-loader’s power train is verified by comparing experimental and simulated results under the same operational conditions. Then shift characteristics were analyzed based on the verified model. Since the shift performance is affected by the pressure in clutch piston, current profile of a proportional pressure control valve to control the automatic transmission was varied for the simulation verification. In the simulations, it was analyzed in terms of shift performance in each stage of fast filling, take-over and clutch slippage, and clutch slippage time. Some parameters affecting the shift performance were also chosen such as friction coefficient, diameter and number of clutch plate while remaining the clutch torque capacity consistently. Especially, relative amplitude of jerk is used in order to decide the regular shift performance. The shift performance on the selected parameters was also analyzed. Finally, to improve the shift quality, the turbine speed with low amplitude of jerk was chosen in the model where a feedback algorithms to control current profiles in applied. Then, the improved shift performance was presented in the simulation verification.