• Title/Summary/Keyword: Long-term stability

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Dry reforming of Propane to Syngas over Ni-CeO2/γ-Al2O3 Catalysts in a Packed-bed Plasma Reactor (충전층 플라즈마 반응기에서 Ni-CeO2/γ-Al2O3 촉매를 이용한 프로페인-합성 가스 건식 개질)

  • Sultana, Lamia;Rahman, Md. Shahinur;Sudhakaran, M.S.P.;Hossain, Md. Mokter;Mok, Young Sun
    • Clean Technology
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    • v.25 no.1
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    • pp.81-90
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    • 2019
  • A dielectric barrier discharge (DBD) plasma reactor packed with $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was used for the dry ($CO_2$) reforming of propane (DRP) to improve the production of syngas (a mixture of $H_2$ and CO) and the catalyst stability. The plasma-catalytic DRP was carried out with either thermally or plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst at a $C_3H_8/CO_2$ ratio of 1/3 and a total feed gas flow rate of $300mL\;min^{-1}$. The catalytic activities associated with the DRP were evaluated in the range of $500{\sim}600^{\circ}C$. Following the calcination in ambient air, the ${\gamma}-Al_2O_3$ impregnated with the precursor solution ($Ni(NO_3)_2$ and $Ce(NO_3)_2$) was subjected to reduction in an $H_2/Ar$ atmosphere to prepare $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst. The characteristics of the catalysts were examined using X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDS), temperature programmed reduction ($H_2-TPR$), temperature programmed desorption ($H_2-TPD$, $CO_2-TPD$), temperature programmed oxidation (TPO), and Raman spectroscopy. The investigation revealed that the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst exhibited superior catalytic activity for the production of syngas, compared to the thermally reduced catalyst. Besides, the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was found to show long-term catalytic stability with respect to coke resistance that is main concern regarding the DRP process.

The Government Organization Act and the Desirable Government Structure in the 21st Century (21세기 바람직한 정부조직과 정부조직법)

  • Sung, Nak-In
    • Journal of Legislation Research
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    • no.44
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    • pp.241-281
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    • 2013
  • First and foremost, a discussion concerning government structure has to be done in connection with the state form and the governmental form. For practical reasons, there is a need to balance the principle of legality and its exceptions under the Government Organization Act. To ensure the flexibility of government structure with respect to the principle of legality, the National Assembly should accept the government structure requested by the newly elected government. This mitigates the rigidity of the principle of the legality within the government organizations. However, excessive changes by each government could violate the principle of legality asked by Constitution. In this sense, arbitrary modification with respect to the government structure by the newly elected government is not desirable. The long term stability of the government organization is required in any case. Secondly, general administrative agencies, other than Executive Ministries, should not be established under the direct order of the President without the control of the Prime Minister. A hierarchy of the executive branch (President->Prime Minister-> Executive Ministries) is stipulated in the Constitution. Establishing a hierarchy of President -> executive institution should be considered unconstitutional. Therefore, only the Presidential Secretariat and institutions with special functions can be established in the Presidential Office. Establishing general administrative agencies in the Presidential Office for convenience purposes is against the spirit of the current Constitution. Consequently, only the office of staffs and special agencies can be placed in the presidential office. It is against the spirit of the current Constitution to found administrative agencies under the presidential office for convenience. Thirdly, the office of the Prime Minister should be the backbone of internal affairs. In that sense, the President, as the head of state, should focus on the big picture such as the direction of the State, while the Cabinet headed by the Prime Minister should be responsible for the daily affairs of the State. The cabinet surrounding the Prime Minister must control all the ordinary affairs of the State, while the President, as the head of the State, should focus on the big picture of blueprinting the aim of the State. Lastly, the Office of the Prime Minister and Executive Ministries are the two main bodies of the executive branch. It is important to reduce the confusion caused by repeated changes in the names of Executive Ministries, to restore the traditional names and authorities of these institutions, and to rehabilitate the legitimacy of the State. For the Korean democracy to take its roots, a systematic way of stabilizing a law-governed democratic country is needed. There is also the need not only to reform security and economic agencies, but also to rationally solve the integration of technique and policy, according to the changes of time.

Stability and Damage Evaluation of the Buddha Triad and 16 Rock-Carved Arhat Statues at Seongbulsa Temple in Cheonan, Korea (천안 성불사 마애석가삼존과 16나한상의 손상도 및 안정성 평가)

  • Yang, Hyeri;Lee, Chan Hee;Jo, Young Hoon
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.78-99
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    • 2020
  • The Buddha triad and 16 Arhat statues carved on the rock surface at Seongbulsa temple is the only domestic remaining example of all 16 Arhats, so its academic value is very high. However, it is severely damaged and so required a stability evaluation through study of digital documentation and precise diagnosis for the purpose of comprehensive conservation. This process established that the Buddha statues were of similar scale, while the Arhats showed a wide variety of sizes, and the two kith and kin in the volume were larger than the Arhats. It was estimated that the statues of food for Buddha are similar to the Arhat statues, and most of the statues are well-formed. The rock used to carve the Buddha statues is banded gneiss with distinct foliation, alternating between white bands of quartz and feldspar and black bands composed of biotite. The Buddha statues have been damaged by physical weathering, discoloration, and biological contamination. In damage evaluations, joint (3.6 crack index), peeling (5.2%), exfoliation (1.7%), and falling off (0.1%) were observed on the rock surface of the Buddha statues. In particular, due to severe biological weathering, stage 9 and 10 biological coverage of the rock surface accounted for 57.5% of the total area, and stages 5 to 8 also accounted for a high share at 22.3%. The discoloration factors were shown to be dark brown and white with Fe, Ca, and S, and a large amount of C detected in the blackened contaminants, and the damage weight high in all areas. Discontinuities in different directions were identified in the rock surface. Analysis of potential rock failure types indicated that there is a possibility of plane and toppling failure, but wedge failure is unlikely to occur. The mean ultrasonic velocity of the main rock surface was 2,463m/sec, the lower part of the left side with a large number of joints was relatively low, and the highly weathered (HW) type to the completely weathered (CW) type concentrated distribution, showing weak properties. For the Buddha statues, conservation treatment is required for about 14.9% of micro cracks and 58.9% of exfoliation cracks. In addition, in order to improve the conservation environment of the Buddha statues, maintenance of drainage and ground preparations for the rock surface gradient and plants are necessary, and protection facilities should be reviewed for long-term conservation and management purposes.

The Effects of Evaluation Attributes of Cultural Tourism Festivals on Satisfaction and Behavioral Intention (문화관광축제 방문객의 평가속성 만족과 행동의도에 관한 연구 - 2006 광주김치대축제를 중심으로 -)

  • Kim, Jung-Hoon
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.2
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    • pp.55-73
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    • 2007
  • Festivals are an indispensable feature of cultural tourism(Formica & Uysal, 1998). Cultural tourism festivals are increasingly being used as instruments promoting tourism and boosting the regional economy. So much research related to festivals is undertaken from a variety of perspectives. Plans to revisit a particular festival have been viewed as an important research topic both in academia and the tourism industry. Therefore festivals have frequently been leveled as cultural events. Cultural tourism festivals have become a crucial component in constituting the attractiveness of tourism destinations(Prentice, 2001). As a result, a considerable number of tourist studies have been carried out in diverse cultural tourism festivals(Backman et al., 1995; Crompton & Mckay, 1997; Park, 1998; Clawson & Knetch, 1996). Much of previous literature empirically shows the close linkage between tourist satisfaction and behavioral intention in festivals. The main objective of this study is to investigate the effects of evaluation attributes of cultural tourism festivals on satisfaction and behavioral intention. accomplish the research objective, to find out evaluation items of cultural tourism festivals through the literature study an empirical study. Using a varimax rotation with Kaiser normalization, the research obtained four factors in the 18 evaluation attributes of cultural tourism festivals. Some empirical studies have examined the relationship between behavioral intention and actual behavior. To understand between tourist satisfaction and behavioral intention, this study suggests five hypotheses and hypothesized model. In this study, the analysis is based on primary data collected from visitors who participated in '2006 Gwangju Kimchi Festival'. In total, 700 self-administered questionnaires were distributed and 561 usable questionnaires were obtained. Respondents were presented with the 18 satisfactions item on a scale from 1(strongly disagree) to 7(strongly agree). Dimensionality and stability of the scale were evaluated by a factor analysis with varimax rotation. Four factors emerged with eigenvalues greater than 1, which explained 66.40% of the total variance and Cronbach' alpha raging from 0.876 to 0.774. And four factors named: advertisement and guides, programs, food and souvenirs, and convenient facilities. To test and estimate the hypothesized model, a two-step approach with an initial measurement model and a subsequent structural model for Structural Equation Modeling was used. The AMOS 4.0 analysis package was used to conduct the analysis. In estimating the model, the maximum likelihood procedure was used.In this study Chi-square test is used, which is the most common model goodness-of-fit test. In addition, considering the literature about the Structural Equation Modeling, this study used, besides Chi-square test, more model fit indexes to determine the tangibility of the suggested model: goodness-of-fit index(GFI) and root mean square error of approximation(RMSEA) as absolute fit indexes; normed-fit index(NFI) and non-normed-fit index(NNFI) as incremental fit indexes. The results of T-test and ANOVAs revealed significant differences(0.05 level), therefore H1(Tourist Satisfaction level should be different from Demographic traits) are supported. According to the multiple Regressions analysis and AMOS, H2(Tourist Satisfaction positively influences on revisit intention), H3(Tourist Satisfaction positively influences on word of mouth), H4(Evaluation Attributes of cultural tourism festivals influences on Tourist Satisfaction), and H5(Tourist Satisfaction positively influences on Behavioral Intention) are also supported. As the conclusion of this study are as following: First, there were differences in satisfaction levels in accordance with the demographic information of visitors. Not all visitors had the same degree of satisfaction with their cultural tourism festival experience. Therefore it is necessary to understand the satisfaction of tourists if the experiences that are provided are to meet their expectations. So, in making festival plans, the organizer should consider the demographic variables in explaining and segmenting visitors to cultural tourism festival. Second, satisfaction with attributes of evaluation cultural tourism festivals had a significant direct impact on visitors' intention to revisit such festivals and the word of mouth publicity they shared. The results indicated that visitor satisfaction is a significant antecedent of their intention to revisit such festivals. Festival organizers should strive to forge long-term relationships with the visitors. In addition, it is also necessary to understand how the intention to revisit a festival changes over time and identify the critical satisfaction factors. Third, it is confirmed that behavioral intention was enhanced by satisfaction. The strong link between satisfaction and behavioral intentions of visitors areensured by high quality advertisement and guides, programs, food and souvenirs, and convenient facilities. Thus, examining revisit intention from a time viewpoint may be of a great significance for both practical and theoretical reasons. Additionally, festival organizers should give special attention to visitor satisfaction, as satisfied visitors are more likely to return sooner. The findings of this research have several practical implications for the festivals managers. The promotion of cultural festivals should be based on the understanding of tourist satisfaction for the long- term success of tourism. And this study can help managers carry out this task in a more informed and strategic manner by examining the effects of demographic traits on the level of tourist satisfaction and the behavioral intention. In other words, differentiated marketing strategies should be stressed and executed by relevant parties. The limitations of this study are as follows; the results of this study cannot be generalized to other cultural tourism festivals because we have not explored the many different kinds of festivals. A future study should be a comparative analysis of other festivals of different visitor segments. Also, further efforts should be directed toward developing more comprehensive temporal models that can explain behavioral intentions of tourists.

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The Research on the Life-safety Implementation using the Natural Light LED Lamp in the Disaster Prevention and Safety Management (방재안전 자연광 LED 조명을 이용한 생활안전 개선에 관한 연구)

  • Lee, Taeshik;Seok, Gumcheul;So, Yooseb;Choi, Byungshik;Kim, Jaekwon;Cho, Woncheol
    • Journal of Korean Society of Disaster and Security
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    • v.9 no.2
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    • pp.53-62
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    • 2016
  • This paper is shown the new method using LED Light, which the light environment is upgraded the natural LED light in the area of Disaster Prevention and Safety Management (PDSD), which the events of deaths is reduced on the Suicide, the Infectious diseases, the safety accidents, the Traffic Accident, the crime, the fire, the Nature Disaster, and which the health and the environment and the safety is implemented using the value of the color LED Light. Research findings include,during 3 weeks in the November 2016, in the ten residents (average living 28.7 years, age 67.5 years) with depressive symptoms in the northern part of Seoul, according to the request of the user, the PDSD natural light LED lighting was installed in the home bedroom or the living room, expectations for the ability to restore physical and mental stability were high (88%), in the same way, after 1 week and 3 weeks, the physical and mental changes were compared and the results,84% in the first week and 90% in the third week and thereafter, the effect of relieving depression was high. We conclude that patients with depression have a good sleep, an uneasy feeling, a sense of security, a good night's sleep, and a good feeling. The PDSD LED Light is expected to contribute in the various areas, which reduced the suicides, which give increased immunity from infectious diseases, which give a crash to reduce accidents caused by negligence, which improve the safe operation of heavy vehicles in which a traffics accident incidence installed on the highest point, which improve the safety function on the 'safety way home' for the safety of the community, which due to fire gives alleviate the emotional anxiety of firefighters, which improve the environment for long-term control room working during decision making caused by natural disasters.

The Effect of Contamination of Ion Source on Ionic Current of Quadrupole Mass Spectrometer (사중극 질량 분석기의 이온소스 오염이 이온전류에 미치는 영향)

  • Lee, K.C.;Park, C.J.;Kim, J.T.;Oh, E.S.;Hong, K.S.;Hong, S.S.;Lim, I.T.;Yun, J.Y.;Kang, S.W.;Shin, Y.H.
    • Journal of the Korean Vacuum Society
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    • v.18 no.3
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    • pp.197-202
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    • 2009
  • The long term stability of ion current of QMS has been one of key parameters for monitoring gas process in vacuum. The time dependence of ionic current was monitored while the pressure of nitrogen gas was kept at a fixed pressure by introducing the gas into vacuum chamber. The chamber was evacuated to ${\sim}3{\times}10^{-9}\;Torr$ to reduce background signals before the measurement. Two ion sources were tested; one had brownish or black color due to gas contamination and the other one was new, i.e. cleaner. At a nitrogen pressure of $1{\times}10^{-5}\;Torr$, the ionic currents measured by the contaminated ion source decreased faster with time. The decrease rate was respectively ${\sim}46%$ for cleaner one and ${\sim}84%$ for contaminated one after ${\sim}5.5%$ hours. In order to test the effect of filament material on the ion current decrease, we fabricated a tungsten(W) filament which consisted of two parts; one half was made of W and the other was coated with yttria. The similar decrease of ionic currents were shown for the two types of filaments, indicating that slight change of temperature of filament due to material difference i.e. baking effect could not improve the origin of ionic current decrease. Overall the decreasing rate of ionic current is more closely associated with contaminated ion source of QMS rather than its filament materials.

The Early Results of Tricuspid Valvuloplasty with Using the Edwards MC3 Annuloplasty System (Edwards MC3 Annuloplasty System을 이용한 삼첨판 성형술의 조기 성적)

  • Oh, Tak-hyuck;Cho, Joon-Yong;Lee, Jong-Tae;Kim, Gun-Jik;Kim, Dae-Hyun
    • Journal of Chest Surgery
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    • v.42 no.1
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    • pp.28-33
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    • 2009
  • Background: Functional tricuspid regurgitation (TR) greater than or equal to a mild grade requires tricuspid valvuloplasty, and tricuspid valvuloplasty with ring annuloplasty has shown good outcomes. We report here on our early experience with the Edwards $MC^3$ annuloplasty system (Edwards LifeSciences, Irvine, CA). Material and Method: From November 2004 to July 2006, 72 patients with tricuspid annular dilatation and TR underwent tricuspid valvuloplasty with using the Edwards $MC^3$ annuloplasty ring. Sixty-eight patients were operated on via median sternotomy and four patients were operated on using robotic assisted minimal invasive thoracotomy. The patient population included 21 males and 51 females and their mean age was $53.9{\pm}12.3$. The mean grade of TR, as assessed by the preoperative echocardiography, was $2.2{\pm}1.0$. The mean NYHA functional class was $3.1{\pm}0.8$. The mean left ventricular ejection fraction was $57.0{\pm}9.9$%. Result: The TR and NYHA functional class, as assessed by postoperative echocardiography, was significantly reduced (mean=$0.4{\pm}0.6$ and $2.0{\pm}0.7$, respectively p<0.001). There was one case of hospital mortality. One patient required permanent pacemaker insertion for third degree atrioventricular block. Conclusion: Our study shows that the Edwards $MC^3$ remodeling ring is easy to implant and it effectively corrects functional TR with excellent clinical and echocardiographic outcomes. Further follow-up and a larger clinical series are required to establish the long-term stability of this repair technique.

Stable Transmission and Continuous Expression of Human Interleukin-10 Transgene in the Offspring of Transgenic Mice (형질전환 생쥐의 후대에서 인간 Interleukin-10 유전자의 안정적 전이와 지속적인 발현)

  • Zheng Z. Y.;Koo D. B.;Han Y. M.;Lee K. K.
    • Reproductive and Developmental Biology
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    • v.28 no.3
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    • pp.203-207
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    • 2004
  • The transgenic mice carrying human Interleukin-10 (hIL-10) gene in conjunction with bovine (3 -casein promoter express hIL-10 in milk during lactation. In this study, stability of germ line transmission and expression of hIL-10 transgene integrated into host chromosome were monitored up to generation F8 of transgenic mice. When male mouse of generation F8 was crossbred with normal females, approximately half of offspring (50.9±5.8%) were identified as transgenic mice. Generation F9 to F15 mice also showed similar transmission rates (66.0±20.1%, 61.5±16.7%, 41.1±8.4%, 40.7±20.3%, 61.3±10.8%, 49.2±18.8% and 43.8±25.9%, respectively), implying that hIL-10 transgene can be transmitted stably up to long term generation in the transgenic mice. Expression levels of human IL-10 from milk of generation F9 to F14 mice were 3.6± 1.2 mg/ml, 4.2±0.9 mg/ml, 5.7±1.5 mg/ml, 6.3±3.5 mg/ml, 6.8±4.5 mg/ml and 6.8±3.1 mg/ml, respectively, which was showed high-level expression compared with that of generation F1 (1.6 mg/ml) mice. In conclusion, our results suggest that transgenic mice can be continuously passed their transgenes to the progeny through the breeding program with the same productivity of human IL-10 protein in their milk.

정지궤도 통신해양기상위성의 기상분야 요구사항에 관하여

  • Ahn, Myung-Hwan;Kim, Kum-Lan
    • Atmosphere
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    • v.12 no.4
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    • pp.20-42
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    • 2002
  • Based on the "Mid to Long Term Plan for Space Development", a project to launch COMeS (Communication, Oceanography, and Meteorological Satellite) into the geostationary orbit is undergoing. Accordingly, KMA (Korea Meteorological Administration) has defined the meteorological missions and prepared the user requirements to fulfill the missions. To make a realistic user requirements, we prepared a first draft based on the ideal meteorological products derivable from a geostationary platform and sent the RFI (request for information) to the sensor manufacturers. Based on the responses to the RFI and other considerations, we revised the user requirement to be a realistic plan for the 2008 launch of the satellite. This manuscript introduces the revised user requirements briefly. The major mission defined in the revised user requirement is the augmentation of the detection and prediction ability of the severe weather phenomena, especially around the Korean Peninsula. The required payload is an enhanced Imager, which includes the major observation channels of the current geostationary sounder. To derive the required meteorological products from the Imager, at least 12 channels are required with the optimum of 16 channels. The minimum 12 channels are 6 wavelength bands used for current geostationary satellite, and additional channels in two visible bands, a near infrared band, two water vapor bands and one ozone absorption band. From these enhanced channel observation, we are going to derive and utilize the information of water vapor, stability index, wind field, and analysis of special weather phenomena such as the yellow sand event in addition to the standard derived products from the current geostationary Imager data. For a better temporal coverage, the Imager is required to acquire the full disk data within 15 minutes and to have the rapid scan mode for the limited area coverage. The required thresholds of spatial resolutions are 1 km and 2 km for visible and infrared channels, respectively, while the target resolutions are 0.5 km and 1 km.

A STUDY ON SKELETAL RELAPSE PATTERNS FOLLOWING ORTHOGNATHIC SURGERY OF CLASS III PATIENTS : COMPARISON BETWEEN SSRO AND IVRO (제 III급 부정교합자의 악교정 수술후 골격적 재발 양상에 관한 연구 : 구내 시상 분할 골절단술과 구내 상행지 수직 골절단술의 비교)

  • Lee, Jang-Yeol;Yu, Hyung-Seog;Ryu, Young-Kyu
    • The korean journal of orthodontics
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    • v.28 no.3 s.68
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    • pp.461-477
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    • 1998
  • To evaluate the relapse pattern and long-term stabilities depanding on surgical methods following orthognathic surgery of Cl III patients, the author selected 24 subjects(10 male, 14 female) operated by SSRO and 26 subjects(10 male,16 female) operated by IVRO. Each subject took four lateral cephalograms : just before surgery(T1), within 48hrs after surgery(T2), 4-8 wks after surgery(T3), 6 month or more after surgery(T4), and the landmarks were digitized. The differences of relapse patterns in each interval between two groups were compared and the significance of correlation among the variables of each group was tested. The obtained results are as follows ; 1. Horizontal early relapse was forward movement of mandible in SSRO group, as compared to the backward movement in IVRO group, and there was a statistical significance between the two groups. 2. Vertical early and late relapses were decreases in anterior facial height in both groups and there was no statistical significance between the two groups. 3. There was a statistical significance in negative correlation between mandibular horizontal late relapse and surgical change of articular angle in SSRO group. 4. There was a statistical significance in negative correlation between amount of mandibular set-back and mandibular horizontal early relapse in both groups.

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