• Archives of design research
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• v.16 no.4
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• pp.385-394
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• 2003

An investigation by KRNIC (Korea Network Information Center) on the real state of usage of internet has shown that 96.9％ of children investigated had experiences of using internet. Especially the firstly ranked item that had been answered by children as a necessity of internet was 'Studying to solve tasks' rated by 83.9％. As seen from the research result, the need as a homework sonics is actually so dominant that it cannot be ignored when considering the profitability at the area of education contents, but any profound research has not been accomplished yet. Internet has been positioned as a more effective and fruitful learning tool, and also all activities done by users for exploring informations and choosing learning items under the on-line circumstances are based on the successive mutual reactions between users and computers. Up to now much of the web based learning circumstances has been introducing the User Interface using metaphor, and the same is found dominantly from the sites for children. But in spite of the availability of metaphor mentioned above the current status is much lack of profound researches about metaphor interface; and what is more, in the case of the site for elementary school students the gap of the ability recognizing metaphor is very large between lower classes and higher classes according to the degree of mental growth but that is used to be simply ignored, then a common concept is adapted to interface for all grades of classes and moreover for infant and kindergarten without any objections. Based on foregoing problems this research has put the main focus on the groping and presenting desirable directions on the prospect design of interface for children-oriented sites by analyzing the status of practical usage of metaphor interface in the field of the sites for children-oriented learning sites with concentration upon homework supporting domains.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.83-91
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• 2011

Purpose: Microfracture has been used as a first-line treatment to repair articular cartilage defects. In this study, a new technique using an extracelluar matrix biomembrane to cover the cartilage lesions after microfracture was evaluated in terms of cartilage repairability and clinical outcome compared with conventional microfracture technique in a prospective randomized trial. Materials and Methods: A total of 53 patients (59 cases) without osteoarthritis who had focal full thickness articular cartilage lesions were randomly assigned in two group. Seventeen patients (17 cases) underwent conventional microfracture procedure (control group) and thirty-six patients (42 cases) received microfracture and placing biomembrane cover (ArtiFilm$^{TM}$) concomitantly (experimental group). Clinical assessment was done through 6 months postoperatively using the subjective International Knee Documentation Committee IKDC questionnaire, and visual analog scale (VAS) for pain and satisfaction. Magnetic resonance imaging (MRI) was performed at 6 months after the operation in all patients. Results: In clinical outcomes, the significant difference was observed between both groups in IKDC, but not in VAS for pain and for satisfaction (final outcomes of IKDC, p=0.001; VAS for pain, p=0.074; VAS for satisfaction, p=0.194). The MRI showed good to complete defect fill (67 to 100%) in 33 patients (78.6%) of experimental group and 4 patients (23.5%) of control group, respectively. In control group, 9 of 17 patients (52.9%) showed poor defect fill (less than 33%), whereas 5 (11.9%) in experimental group (p=0.001). Assessment of peripheral integration revealed no gap formation in 35 patients (83.3%) in experimental group and 6 patients (35.3%) in control group (p=0.001). No serious complications or adverse effects related to the biomembrane were found. Conclusion: Good short-term follow-up clinical results were obtained in the group whose cartilage defects in the knee joint were covered with biomembrane after the microfracture, with the MRI findings confirming the excellent regeneration of the defective cartilage area. This suggests that the surgery to cover the defective area with biomembrane (ArtiFilm$^{TM}$) after the microfracture procedure is a safe, more effective treatment to induce cartilage regeneration.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.63-72
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• 2012

Current analysis method drives an irrationality a road, signal operation and cause confusion of road such as weaving, bottleneck being not including main traffic flow in analysis subject. Therefore, this research develops analysis method of simple grade facilities to grasp target equipment relationship effect as virtue process to grasp effect of simple grade facilities in city and there is the purpose to apply optimum space of analysis intersection. In this paper, get at effect of simple grade facilities in urban area, as well as, develop new analysis method of simple grade facilities and adapt optimal interval of intersection point. New method of this paper reasonably estimated to optimal interval of the traffic flow(diverge area, merge area). As research result, analysis method to present in this research could clarify vague part of existing analysis method and presume reasonable result. Optimal interval of diverge and merge area with facilities was appeared more then 65m from the main line and more then 45m from the frontage road. Meaning of this paper as follow. First, the effect of simple grade facilities estimate. as consider optimal interval of simple grade facilities in urban can plan efficiently operation planning of road and signal in connection with nearby intersection. Second, new method then previous methods. planner of transportation easily access due to run parallel with existing method. Third, new method is contained through traffic volumes. the existing method did not reflect one. and this new method reduce error to the minimum. when analysis of intersection and link. Fourth, using the new method propose improvement plan with road operation and signal operation.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.37-60
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• 2007

This study has been historically reviewed the clothing and textiles education through references. The clothing and textiles education had been informally offered as a part of household skill, skill of daily life and home skill before the law of school education was established. Therefore, we have reviewed the changes in the clothing and textiles education by separating the prior period between the end of the old Korea and the liberation in 1945, from the later period from the liberation up to now. And also contents of clothing and textiles education between before and after the revision of the 7th curriculum were compared and analyzed. The clothing and textiles education had put emphasis on sewing, handicraft and household during the prior period from the end of the old Korea to the liberation, but after liberation, it became involved in Home Economics Education. The number of classes and the contents of clothing and textiles education had been increased and deepened from the 1st term to the 5th term of curriculum. In particular, the 4th and 5th term of curriculum became a turning point where home life section was intensified. Even though the number of classes was reduced during the 6th term of curriculum, with increase in target school grades for this education, and Home Economics in the middle school remained an independent subject matter. However, during the 7th term of curriculum, Technology-Home Economics Education in the middle school courses led to losing independent subject name and shrinking its contents. Through the revision in the 7th curriculum, the clothing and textiles education achieved great improvement and progress by gaining balance in distribution of contents among school grades and balance between theory and practice. However it still remains as an issue to be more studied and resolved how well the contents are matched with the interests and attention of students. We need to consider and reflect request of students under learner-centered curriculum. Considering enormous changes in the environment surrounding the clothing and textiles education, it is crystal clear that the gap between existing contents of education and teaching methods and our real life will be widened. Because students' perceptions of value have been diversified, it is our task to develop better contents and learning system in order to help students have interests, attention and desire in clothing and textiles life in line with social needs for desirable clothing and textiles education.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.2
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• pp.360-377
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• 2016

Since after the 1986 economic reform policy(Doi Moi), the central highland in Vietnam has transformed into one of the largest coffee producing areas. The transformation had been supported by mass migration of ethnic Kinhs from the coastal lowland. It did not take long for the Kinh migrants to be the ethnic majority in the region. Meanwhile the growth of coffee industry entailed in socio-economic disparity, specially between Kinh migrants and native ethnic minorities. The disparity has becomed obvious not only between coffee farming Kinhs and non-coffee farming ethnic minorities but also between coffee farming Kinhs and ehtnic minorities. The previous literatures highlight the lack of human and social capital and the lagging modernization in ethnic minority societies. However, they fall short in showing the explicit processes why ethnic minority coffee farmers earn less than ethnic majority counterparts. With a case study of Dak Lak province, this research attempts to show the reason why there is income gap between Kinh and ethnic minority Ede coffee farmers by comparing their ways of producing coffee and selling their products. The results show that Ede's land productivity is significantly lower than Kinh's. It is because Ede farmers use less fertilizer due to the shortage of the capital. Also they often get into debt for coffee production and should pay it back right after the harvest. It deprives them of chance to raise earning by selling the coffee beans at a higher price.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.199-218
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• 2005

Purpose of Study: Peripheral nerve regeneration depends on neurotrophism of distal nerve stump, recovery potential of neuron, supporting cell like Schwann cell and neurotrophic factors such as BDNF. Peripheral nerve regeneration can be enhanced by the conduit which connects the both sides of transected nerve. The conduit maintains the effects of neurotrophism and BDNF produced by Schwann cells which can be made by gene therapy. In this study, we tried to enhance the peripheral nerve regeneration by using calcium phosphate coated porous conduit and BDNF-Adenovirus infected Schwann cells in sciatic nerve of rats. Materials and Methods: Microporous filter which permits the tissue fluid essential for nerve regeneration and does not permit infiltration of fibroblasts, was made into 2mm diameter and 17mm length conduit. Then it was coated with calcium phosphate to improve the Schwann cell adhesion and survival. The coated filter was evaluated by SEM examination and MTT assay. For effective allogenic Schwann cell culture, dorsal root ganglia of 1-day old rat were extracted and treated with enzyme and antimitotic Ara-C. Human BDNF cDNA was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into adenovirus shuttle vector pAACCMVpARS in which E1 was deleted. We infected the BDNF-Ad into 293 human mammary kidney cell-line and obtained the virus plaque 2 days later. RT-PCR was performed to evaluate the secretion of BDNF in infected Schwann cells. To determine the most optimal m.o.i of BDNF-Ad, we infected the Schwann cells with LacZ adenovirus in 1, 20, 50, 75, 100, 250 m.o.i for 2 hours and stained with ${\beta}$-galactosidase. Rats(n=24) weighing around 300g were used. Total 14mm sciatic nerve defect was made and connected with calcium phosphate coated conduits. Schwann cells$(1{\times}10^6)$ or BDNF-Ad infected Schwann cells$(1{\times}10^6)$ were injected in conduit and only media(MEM) was injected in control group. Twelve weeks after surgery, degree of nerve regeneration was evaluated with gait analysis, electrophysiologic measurements and histomorphometric analysis. Results: 1. Microporous Millipore filter was effective conduit which permitted the adhesion of Schwann cells and inhibited the adhesion of fibroblast. We could enhance the Schwann cell adhesion and survival by coating Millipore filter with calcium phosphate. 2. Schwann cell culture technique using repeated treatment of Ara-C and GDNF was established. The mean number of Schwann cells obtained 1 and 2 weeks after the culture were $1.54{\pm}4.0{\times}10^6$ and $9.66{\pm}9.6{\times}10^6$. 3. The mRNA of BDNF in BDNF-Ad infected Schwann cells was detected using RT-PCR. In Schwann cell $0.69\;{\mu}g/{\mu}l$ of DNA was detected and in BDNF-Adenovirus transfected Schwann cell $0.795\;{\mu}g/{\mu}l$ of DNA was detected. The most effective infection concentration was determined by LacZ Adenovirus and 75 m.o.i was found the most optimal. Conclusion: BDNF-Ad transfected Schwann cells successfully regenerated the 14mm nerve gap which was connected with calcium phosphate coated Millipore filter. The BDNF-Ad group showed better results compared with Schwann cells only group and control group in aspect to sciatic function index, electrophysiologic measurements and histomorphometric analysis.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.440-456
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• 2019

The controversy of the risk perception related to particulate matters becomes significant. Therefore, in order to understand the nature of the particulate matters, we gathered articles and comments in on-line community related to bicycling which is affected by exposure of the particulate matters. As a result, firstly, the government - led particulate matter policy was strengthened and segmented every period, butthe risk perception related to particulate matters in the bicycle community has become active and serious. Second, as a result of analyzing the perception change of outdoor activities related to particulate matters, bicycle users in community showed a tendency of outdoor activity depending on the degree of particulate matters ratherthan the weather. In addition, the level of the risk perception related to particulate matters has been moved from fears of serious threat in daily life and health, combined with the disregard of domestic particulate matter levels or mask performance. Ultimately, these risk perception related to particulate matters have led some of the bicycling that were mainly enjoyed outdoors to the indoor space. However, in comparison with outdoor bicycling enjoyed by various factors such as scenery, people, and weather, the monotonous indoor bicycling was converted into another type of indoor exercise such as fitness and yoga. In summary, it was derived from mistrust of excessive information or policy provided by the government or local governments. It is considered that environmental policy should be implemented after discussion of risk communication that can reduce the gap between public anxiety and concern so as to cope with the risk perception related to particulate matters. Therefore,this study should be provided as an academic basis for the effective communication direction when decision makers establish the policy related to particulate matters.

• Journal of National Security and Military Science
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• s.13
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• pp.687-738
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• 2016

To prepare for the complicated international relationship regarding Korean Peninsula after reunification, this thesis started off with the awareness that Unified Korea should build its international posture and national security at an early stage by determining its appropriate military strength for independent defense and military strategies that Unified Korea should aim. The main theme of this thesis is 'The research on appropriate military strength of the Unified Korean military'. To derive appropriate military strength of Unified Korea, this research focuses on conflict scenario and relative balance strategy based on potential threats posed by neighboring countries, and this is the part that differentiates this research from other researches. First of all, the main objective of the research is to decide appropriate military strength for Unified Korea to secure defense sufficiency. For this, this research will decide efficient military strategy that Unified Korea should aim. Than by presuming the most possible military conflict scenario, this research will judge the most appropriate military strength for Unified Korea to overcome the dispute. Second, after deciding appropriate military strength, this research will suggest how to operate presumed military strength in each armed force. The result of this thesis is as in the following. First, Unified Korea should aim 'relative balance strategy'. 'Relative balance strategy' is a military strategy which Unified Korea can independently secure defense sufficiency by maintaining relative balance when conflicts occur between neighboring countries. This strategy deters conflicts in advance by relative balance of power in certain time and place. Even if conflict occurs inevitably, this strategy secures initiative. Second, when analyzing neighboring countries interest and strategic environment after unification, the possibility of all-out war will be low in the Korean Peninsula because no other nation wants the Korean Peninsula to be subordinated to one single country. Therefore appropriate military strength of the Unified Korean military would be enough when Unified Korea can achieve relative balance in regional war or limited war. Third, Northeast Asia is a region where economic power and military strength is concentrated. Despite increasing mutual cooperation in the region, conflicts and competition to expand each countries influence is inherent. Japan is constantly enhancing their military strength as they aim for normal statehood. China is modernizing their military strength as they aspire to become global central nation. Russia is also enhancing their military strength in order to hold on to their past glory of Soviet Union as a world power. As a result, both in quality and quantity, the gap between military strength of Unified Korea and each neighboring countries is enlarged at an alarming rate. Especially in the field of air-sea power, arms race is occurring between each nation. Therefore Unified Korea should be equipped with appropriate military strength in order to achieve relative balance with each threats posed by neighboring countries. Fourth, the most possible conflicts between Unified Korea and neighboring countries could be summarized into four, which are Dokdo territorial dispute with Japan, Leodo jurisdictional dispute with China, territorial dispute concerning northern part of the Korea Peninsula with China and disputes regarding marine resources and sea routes with Russia. Based on those conflict scenarios, appropriate military strength for Unified Korea is as in the following. When conflict occurs with Japan regarding Dokdo, Japan is expected to put JMSDF Escort Flotilla 3, one out of four of its Japan Maritime Self-Defense Force Escort Fleet, which is based in Maizuru and JMSDF Maizuru District. To counterbalance this military strength, Unified Korea needs one task fleet, comprised with three task flotilla. In case of jurisdictional conflict with China concerning Leodo, China is expected to dispatch its North Sea fleet, one out of three of its naval fleet, which is in charge of the Yellow Sea. To response to this military action, Unified Korea needs one task fleet, comprised with three task flotilla. In case of territorial dispute concerning northern part of the Korean Peninsula with China, it is estimated that out of seven Military Region troops, China will dispatch two Military Region troops, including three Army Groups from Shenyang Military Region, where it faces boarder with the Korean Peninsula. To handle with this military strength, Unified Korea needs six corps size ground force strength, including three corps of ground forces, two operational reserve corps(maneuver corps), and one strategic reserve corps(maneuver corps). When conflict occurs with Russia regarding marine resources and sea routes, Russia is expected to send a warfare group of a size that includes two destroyers, which is part of the Pacific Fleet. In order to balance this strength, Unified Korea naval power requires one warfare group including two destroyers. Fifth, management direction for the Unified Korean military is as in the following. Regarding the ground force management, it would be most efficient to deploy troops in the border area with china for regional and counter-amphibious defense. For the defense except the border line with china, the most efficient form of force management would be maintaining strategic reserve corps. The naval force should achieve relative balance with neighboring countries when there is maritime dispute and build 'task fleet' which can independently handle long-range maritime mission. Of the three 'task fleet', one task fleet should be deployed at Jeju base to prepare for Dokdo territorial dispute and Leodo jurisdictional dispute. Also in case of regional conflict with china, one task fleet should be positioned at Yellow Sea and for regional conflict with Japan and Russia, one task fleet should be deployed at East Sea. Realistically, Unified Korea cannot possess an air force equal to neither Japan nor China in quantity. Therefore, although Unified Korea's air force might be inferior in quantity, they should possess the systematic level which Japan or China has. For this Unified Korea should build air base in island areas like Jeju Island or Ullenong Island to increase combat radius. Also to block off infiltration of enemy attack plane, air force needs to build and manage air bases near coastal areas. For landing operation forces, Marine Corps should be managed in the size of two divisions. For island defense force, which is in charge of Jeju Island, Ulleung Island, Dokdo Island and five northwestern boarder island defenses, it should be in the size of one brigade. Also for standing international peace keeping operation, it requires one brigade. Therefore Marine Corps should be organized into three divisions. The result of the research yields a few policy implications when building appropriate military strength for Unified Korea. First, Unified Korea requires lower number of ground troops compared to that of current ROK(Republic of Korea) force. Second, air-sea forces should be drastically reinforced. Third, appropriate military strength of the Unified Korean military should be based on current ROK military system. Forth, building appropriate military strength for Unified Korea should start from today, not after reunification. Because of this, South Korea should build a military power that can simultaneously prepare for current North Korea's provocations and future threats from neighboring countries after reunification. The core of this research is to decide appropriate military strength for Unified Korea to realize relative balance that will ensure defense sufficiency from neighboring countries threats. In other words, this research should precisely be aware of threats posed by neighboring countries and decide minimum level of military strength that could realize relative balance in conflict situation. Moreover this research will show the path for building appropriate military strength in each armed force.

• Journal of Global Scholars of Marketing Science
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• v.18 no.2
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• pp.147-187
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• 2008

Online game researchers focus on the flow and factors influencing flow. Flow is conceptualized as an optimal experience state and useful explaining game experience in online. Many game studies focused on the customer loyalty and flow in playing online game, In showing specific game experience, however, it doesn't examine multidimensional experience process. Flow is not construct which show absorbing process, but construct which show absorbing result. Hence, Flow is not adequate to examine multidimensional experience of games. Online game is included in hedonic consumption. Hedonic consumption is a relatively new field of study in consumer research and it explores the consumption experience as a experiential view(Hirschman and Holbrook 1982). Hedonic consumption explores the consumption experience not as an information processing event but from a phenomenological of experiential view, which is a primarily subjective state. It includes various playful leisure activities, sensory pleasures, daydreams, esthetic enjoyment, and emotional responses. In online game experience, therefore, it is right to access through a experiential view of hedonic consumption. The objective of this paper was to make up for lacks in our understanding of online game experience by developing a framework for better insight into the hedonic experience of online game. We developed this framework by integrating and extending existing research in marketing, online game and hedonic responses. We then discussed several expectations for this framework. We concluded by discussing the results of this study, providing general recommendation and directions for future research. In hedonic response research, Lacher's research(1994)and Jongho lee and Yunhee Jung' research (2005;2006) has served as a fundamental starting point of our research. A common element in this extended research is the repeated identification of the four hedonic responses: sensory response, imaginal response, emotional response, analytic response. The validity of these four constructs finds in research of music(Lacher 1994) and movie(Jongho lee and Yunhee Jung' research 2005;2006). But, previous research on hedonic response didn't show that constructs of hedonic response have cause-effect relation. Also, although hedonic response enable to different by stimulus properties. effects of stimulus properties is not showed. To fill this gap, while largely based on Lacher(1994)' research and Jongho Lee and Yunhee Jung(2005, 2006)' research, we made several important adaptation with the primary goal of bringing the model into online game and compensating lacks of previous research. We maintained the same construct proposed by Lacher et al.(1994), with four constructs of hedonic response:sensory response, imaginal response, emotional response, analytical response. In this study, the sensory response is typified by some physical movement(Yingling 1962), the imaginal response is typified by images, memories, or situations that game evokes(Myers 1914), and the emotional response represents the feelings one experiences when playing game, such as pleasure, arousal, dominance, finally, the analytical response is that game player engaged in cognition seeking while playing game(Myers 1912). However, this paper has several important differences. We attempted to suggest multi-dimensional experience process in online game and cause-effect relation among hedonic responses. Also, We investigated moderate effects of perceived complexity. Previous studies about hedonic responses didn't show influences of stimulus properties. According to Berlyne's theory(1960, 1974) of aesthetic response, perceived complexity is a important construct because it effects pleasure. Pleasure in response to an object will increase with increased complexity, to an optimal level. After that, with increased complexity, pleasure begins with a linearly increasing line for complexity. Therefore, We expected this perceived complexity will influence hedonic response in game experience. We discussed the rationale for these suggested changes, the assumptions of the resulting framework, and developed some expectations based on its application in Online game context. In the first stage of methodology, questions were developed to measure the constructs. We constructed a survey measuring our theoretical constructs based on a combination of sources, including Yingling(1962), Hargreaves(1962), Lacher (1994), Jongho Lee and Yunhee Jung(2005, 2006), Mehrabian and Russell(1974), Pucely et al(1987). Based on comments received in the pretest, we made several revisions to arrive at our final survey. We investigated the proposed framework through a convenience sample, where participation in a self-report survey was solicited from various respondents having different knowledges. All respondents participated to different degrees, in these habitually practiced activities and received no compensation for their participation. Questionnaires were distributed to graduates and we used 381 completed questionnaires to analysis. The sample consisted of more men(n=225) than women(n=156). In measure, the study used multi-item scales based previous study. We analyze the data using structural equation modeling(LISREL-VIII; Joreskog and Sorbom 1993). First, we used the entire sample(n=381) to refine the measures and test their convergent and discriminant validity. The evidence from both the factor analysis and the analysis of reliability provides support that the scales exhibit internal consistency and construct validity. Second, we test the hypothesized structural model. And, we divided the sample into two different complexity group and analyze the hypothesized structural model of each group. The analysis suggest that hedonic response plays different roles from hypothesized in our study. The results indicate that hedonic response-sensory response, imaginal response, emotional response, analytical response- are related positively to respondents' level of game satisfaction. And game satisfaction is related to higher levels of game loyalty. Additionally, we found that perceived complexity is important to online game experience. Our results suggest that importance of each hedonic response different by perceived game complexity. Understanding the role of perceived complexity in hedonic response enables to have a better understanding of underlying mechanisms at game experience. If game has high complexity, analytical response become important response. So game producers or marketers have to consider more cognitive stimulus. Controversy, if game has low complexity, sensorial response respectively become important. Finally, we discussed several limitations of our study and suggested directions for future research. we concluded with a discussion of managerial implications. Our study provides managers with a basis for game strategies.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.736-745
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• 1998

Background: Respiratory muscle interaction is further profoundly affected by a number of pathologic conditions. Hyperinflation may be particularly severe in chronic obstructive pulmonary disease(COPD) patients, in whom the functional residual capacity(FRC) often exceeds predicted total lung capacity(TLC). Hyperinflation reduces the diaphragmatic effectiveness as a pressure generator and reduces diaphragmatic contribution to chest wall motion. Ultrasonography has recently been shown to be a sensitive and reproducible method of assessing diaphragmatic excursion. This study was performed to evaluate how differences of diaphragmatic excursion measured by ultrasonography associate with normal subjects and COPD patients. Methods: We measured diaphragmatic excursions with ultrasonography on 28 healthy subjects(l6 medical students, 12 age-matched control) and 17 COPD patients. Ultrasonographic measurements were performed during tidal breathing and maximal respiratory efforts approximating vital capacity breathing using Aloka KEC-620 with 3.5 MHz transducer. Measurements were taken in the supine posture. The ultrasonographic probe was positioned transversely in the midclavicular line below the right subcostal margin. After detecting the right hemidiaphragm in the B-mode the ultrasound beam was then positioned so that it was approximately parallel to the movement of middle or posterior third of right diaphragm. Recordings in the M-mode at this position were made throughout the test. Measurements of diaphragmatic excursion on M-mode tracing were calculated by the average gap in 3 times-respiration cycle. Pulmonary function test(SensorMedics 2800), maximal inspiratory(PImax) and expiratory mouth pressure(PEmax, Vitalopower KH-101, Chest) were measured in the seated posture. Results: During the tidal breathing, diaphragmatic excursions were recorded $1.5{\pm}0.5cm$, $1.7{\pm}0.5cm$ and $1.5{\pm}0.6cm$ in medical students, age-matched control group and COPD patients, respectively. Diaphragm excursions during maximal respiratory efforts were significantly decreased in COPD patients ($3.7{\pm}1.3cm$) when compared with medical students, age-matched control group($6.7{\pm}1.3cm$, $5.8{\pm}1.2cm$, p< 0.05}. During maximal respiratory efforts in control subjects, diaphragm excursions were correlated with $FEV_1$, FEVl/FVC, PEF, PIF, and height. In COPD patients, diaphragm excursions during maximal respiratory efforts were correlated with PEmax(maximal expiratory pressure), age, and %FVC. In multiple regression analysis, the combination of PEmax and age was an independent marker of diaphragm excursions during maximal respiratory efforts with COPD patients. Conclusion: COPD subjects had smaller diaphragmatic excursions during maximal respiratory efforts than control subjects. During maximal respiratory efforts in COPD patients, diaphragm excursions were well correlated with PEmax. These results suggest that diaphragm excursions during maximal respiratory efforts with COPD patients may be valuable at predicting the pulmonary function.