• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.17-17
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• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• 한국지역지리학회지
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• 제6권2호
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• pp.1-19
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• 2000

본 연구는 중부지역의 중심지로 발전하고 있는 대전광역시를 대상으로 노령화 지구의 공간적 분포 패턴을 분석하고자 하였다. 그 결과 노령화 지구는 대전광역시 CBD지역과 CBD인접지역, 그리고 주변지역간에 뚜렷한 차이를 나타내고 있으며, 그 분포에 있어서도 양극화 현상이 뚜렷함을 확인하였다. 그리고 인구감소지구는 노령화지구와 대체로 중복되어 있고, 비노령인구의 전출에 의하여 노령인구비율이 높아지고 있으며, 인구증가지구는 노령화 지구와 전혀 중복되어 나타나지 않고, 비노령인구의 전입에 의해 노령인구비율이 낮아지고 있다. 인구이동에 의한 노령인구의 증가여부를 확인하기 위하여 각 그룹별로 연령 코호트 분석방법을 이용하여 노령화 지구의 출현요인을 분석한 결과, 인구노령화의 진행 은 인구의 사회적 증감률 변화와 매우 밀접하게 관련되어 있고, 특히 비노령인구의 전출에 의해 노령인구비율이 높아지고 있음을 확인할 수 있었다. CBD지역과 CBD인접지역을 포함한 중심시가지에서는 결혼, 새로운 주택취득에 의한 세대분리 등의 전출, 즉, 비노령인구의 전출이 인구노령화를 촉진하는 주요인이 되고 있고, 반면 주변지역에서는 비노령인구의 지구의로의 전출뿐 아니라 새롭게 노령인구로 편입되어져 가는 연령층 인구와 사망률의 저하에 따른 평균수명의 연장으로 인한 노령인구의 절대적 증대가 인구노령화를 촉진하는 요인으로 작용하고 있다.

• 마케팅과학연구
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• 제19권1호
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• pp.23-35
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• 2009

A hypermarket as the one of the most globally standardized retailing format is also the type of store among various types of stores that the most active in expanding into other foreign markets. Recently, as several Korean retailing companies start to penetrate into Chinese market they differentiate themselves with modern facilities and customers service oriented high-end concept. China and Korea as Far East Asian countries share many common values, however precise and careful analysis should be carried out since there may also be critical differences in socio-economic aspects as well as in consumption patterns due to the level of development stages of retail industry among two countries. Even though precise and careful study is crucial on Chinese retailing market and consumers, none of researches and studies on 'how the quality of service dimensional structure is different between Korea and China', and 'what will be the most important and influential service dimensional factors for Chinese consuers compared to the hypermarkets customers in Korea' in order to improve the level of Chinese consumers satisfaction' have been fulfilled At this point of view, this study uses KD-SQS (Rho Eun Jung & Sir Yong Gu, 2008) which is a measure of Korean hypermarkets service quality to set up a hypothesis on Korean and Chinese consumers, and an empirical analysis is conducted. We try to get the answers about how the comparative importance of Service quality dimensions which decides the level of customer satisfaction is different depending on the cultural dimensions and socio-economic factors among two countries, Korea and China. Based upon the results, we try to give a valuable suggestion of what service dimensional factors should be reinforced to improve the level of CS in Chinese retailing market. Hypotheses for this study are as follows : H1. Each dimension of Service Quality significantly affects the level of CS H2. The effect of 'Basic Benefit' in service quality dimensions on the level of CS is greater in China than in Korea H3. The effect of 'Promotion' in service quality dimensions on the level of CS is greater in China than in Korea H4. The effect of 'Physical Aspects'in service quality dimensions on the level of CS is greater in Korea than in China. H5. The effect of 'Personal Interaction' in service quality dimensions on the level of CS is greater in China than in Korea H6. The effect of 'Policy' in service quality dimensions on the level of CS will be greater in Korean than in China H7. The effect of additional convenience in service quality dimensions on the level of CS will be greater in Korean than in China. More than 1,100 data were collected directly from the surveys of Chinese and Korean consumers in order to verify the hypotheses above. In Korea, stores which have floor space of over $9,000m^2$and opened later than year 2000 were selected for the samples, and thus Gayang, Wolgye, Sangbong, Eunpyeong, Suh-Suwon, Gojan stores and their customers were surveyed. In China, notable differences in the income levels and consumer behaviors between cities and regions were considered, and thus the research area was limited to the stores only in Shanghai. 6 stores which have the size of over $6,000m^2$ and opened later than 2000, such as Ruihong, Intu, Mudanjang, Sanrin, Raosimon, and Ranchao stores were selected for the survey. SPSS 12.0 and AMOS 7.0 were used as statistical tools, and exploratory factor analysis, confirmatory factor analysis, and multi-group analysis were conducted. In order to carry out a multi group analysis that decides whether the structure variables which shows the different effects of 6 service dimensions in Korean and Chinese groups is statistically valid, configural invariance, metric invariance, and structural invariance are tested in order. At the results of the tests, 3 out of 7 hypotheses were supported and other 4 hypotheses were denied. According to the study, 4 dimensions (Basic Benefit, Physical Environment, Policy, and additional convenience) were positively correlated with CS in Korea, and 3 dimensions (i.e. basic benefit, policy, additional convenience) were significant in China. However, the significance of the service-dimensions was turned out to be partially different in Korea and China. The Basic Benefit is more influential in deciding the level of CS in china than Korea, however Physical Aspect is more important factor in Korea. 'Policy dimension' did not make significant difference between two countries. In the 'additional convenience dimension', the differences in 'socio-economic factors' than in'cultural background' were considered as more important in Chinese consumers than Korean. Overall, the improvement of Service quality will be crucial factors to increase the level of CS in Chinese market same as Korean market. In addition, more emphases need to be placed on the service qualities of 'Basic Benefit' and 'additional convenience' dimensions in China. In particular, 'low price' and 'product diversity' that constitute 'Basic Benefit' are proved to be comparatively disadvantageous and weak points of Korean companies compared to global players, and thus the prompt strengthening those dimensions would be urgent for Korean retailers. Moreover, additional conveniences such as various tenants and complex service and entertaining area will be more important in China than in Korea. Besides, Applying advanced Korean Hypermaret`s customer policy to Chinese consumers will help to get higher reliability and to differentiate themselves to other competitors. However, as personal interaction, physical aspect, promotions were proved as not significant for the level of CS in China, Korean companies need to reconsider the priority order of resource allocations when they tap into Chinese market.

• 한국전통조경학회지
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• 제31권2호
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• pp.43-57
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• 2013

본 연구는 소쇄원 48영의 잠재적 의미경관 구성에 있어서 인간의 본성과 우주적 보편적 질서를 연결하는 사유체계라 할 수 있는 음양오행론(陰陽五行論)적 의미를 추출하는데 목적이 있다. 지금까지의 논의를 정리하면 다음과 같다. 1. 소쇄원 48영에 대한 음양(陰陽)적 경관구성 중 자연과 행위의 관계를 형상화 한 시문은 작중 화자가 산수를 유유자적하게 완상하거나 답사하는 동적인 모습을 그렸다. 주로 양(陽)의 배속을 통해 동 남쪽에서 창작된 경우가 많았다. 반면 정적인 음(陰)의 경관구성이라 할 수 있는 자연과 경물을 형상화 한 시문은 북 서쪽 부근에서 창작된 경우가 많았다. 자연과 인공 경물을 작품으로 형상화 한 시문은 김인후 자신이 경물을 두고 의미경관을 표출하고자 한 경우와 있는 그대로의 사실적 정원의 이미지를 묘사한 경우로 구분 지을 수 있다. 시문은 행위의 표현보다는 경물을 형상화하는데 치중했음을 보여준다. 또한 제1영과 마지막 작품인 '장원제영'의 시문이 모두 같은 구역 안에 있다는 것은 음과 양, 자연의 순환원리가 내재된 종시(終始)적 공간으로 파악했다는 것을 알 수 있었다. 2. 소쇄원 48영에 대한 오행론(五行論)적 경관해석 중 발산(發散)에 의해 결합된 세계로서 목(木), 화(火)기(氣)를 들 수 있다. 먼저 목의 성정을 나타내는 시문은 경물을 형상화 한 시문이 많았으며, 정내의 전체구도에서 동향인 오곡문 구역에 배치되어 있었다. 시문의 내용은 유연하고 소박함 속에서 발생과 곡직(曲直)을 나타내고 있다. 화의 성정을 나타내는 시문은 행위를 형상화 한 시문이 많았으며, 정내에서는 낮에 해가 위치하는 남향인 애양단 구역에서 창작되었다. 모두 양의 속성인 발산과 상승을 특징으로 하는 변(變)의 운동에 오른 상태라 할 수 있다. 3. 소쇄원 48영에 대한 오행론적 경관해석 중 수렴(收斂)에 의해 결합된 세계로서 금(金), 수(水)기를 들 수 있다. 먼저 금의 성정을 나타내는 시문들은 모두 경물을 형상화 한 시문이었고, 정내의 전체구도에서는 서향인 대나무 숲 구역에 배치되어 있음을 알 수 있었다. 사계절 중 가을의 경치를 나타내며, 선비의 단호함과 의로움의 정결을 나타내고 있다. 수의 성정을 표현한 시문은 정원의 가장 상단이라 할 수 있는 북향의 제월당 부근에서 창작되었으며, 시간적으로 저녁 늦은 밤 달맞이를 하는 행위를 형상화 한 시문과 설경의 자연경물을 형상화 한 시문이었다. 모두 수렴에 의한 음으로 화(化)하는 기운을 표현한 시문이라 할 수 있다. 4. 소쇄원 48영에 대한 오행론적 경관해석 중 수렴과 발산의 복합체라 할 수 있는 토(土)의 성정을 나타내는 시문은 내원의 경관 중 중앙에 위치한 광풍각 계류주변이며, 자연현상과 인공경물을 통해 작가의 행위를 매개하고 있다.

• Asia pacific journal of information systems
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• 제18권4호
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• pp.27-55
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• 2008

Due to the increasing and intensifying competition in the Internet shopping market, it has been recognized as very important to develop an effective policy and strategy for acquiring loyal customers. For this reason, web site designers need to know if a new Internet shopping mall(ISM) will be accepted. Researchers have been working on identifying factors for explaining and predicting user acceptance of an ISM. Some studies, however, revealed inconsistent findings on the antecedents of user acceptance of a website. Lack of consideration for individual differences in user ability is believed to be one of the key reasons for the mixed findings. The elaboration likelihood model (ELM) and several studies have suggested that individual differences in ability plays an moderating role on the relationship between the antecedents and user acceptance. Despite the critical role of user ability, little research has examined the role of user ability in the Internet shopping mall context. The purpose of this study is to develop a user acceptance model that consider the moderating role of user ability in the context of Internet shopping. This study was initiated to see the ability of the technology acceptance model(TAM) to explain the acceptance of a specific ISM. According to TAM. which is one of the most influential models for explaining user acceptance of IT, an intention to use IT is determined by usefulness and ease of use. Given that interaction between user and website takes place through web interface, the decisions to accept and continue using an ISM depend on these beliefs. However, TAM neglects to consider the fact that many users would not stick to an ISM until they trust it although they may think it useful and easy to use. The importance of trust for user acceptance of ISM has been raised by the relational views. The relational view emphasizes the trust-building process between the user and ISM, and user's trust on the website is a major determinant of user acceptance. The proposed model extends and integrates the TAM and relational views on user acceptance of ISM by incorporating usefulness, ease of use, and trust. User acceptance is defined as a user's intention to reuse a specific ISM. And user ability is introduced into the model as moderating variable. Here, the user ability is defined as a degree of experiences, knowledge and skills regarding Internet shopping sites. The research model proposes that the ease of use, usefulness and trust of ISM are key determinants of user acceptance. In addition, this paper hypothesizes that the effects of the antecedents(i.e., ease of use, usefulness, and trust) on user acceptance may differ among users. In particular, this paper proposes a moderating effect of a user's ability on the relationship between antecedents with user's intention to reuse. The research model with eleven hypotheses was derived and tested through a survey that involved 470 university students. For each research variable, this paper used measurement items recognized for reliability and widely used in previous research. We slightly modified some items proper to the research context. The reliability and validity of the research variables were tested using the Crobnach's alpha and internal consistency reliability (ICR) values, standard factor loadings of the confirmative factor analysis, and average variance extracted (AVE) values. A LISREL method was used to test the suitability of the research model and its relating six hypotheses. Key findings of the results are summarized in the following. First, TAM's two constructs, ease of use and usefulness directly affect user acceptance. In addition, ease of use indirectly influences user acceptance by affecting trust. This implies that users tend to trust a shopping site and visit repeatedly when they perceive a specific ISM easy to use. Accordingly, designing a shopping site that allows users to navigate with heuristic and minimal clicks for finding information and products within the site is important for improving the site's trust and acceptance. Usefulness, however, was not found to influence trust. Second, among the three belief constructs(ease of use, usefulness, and trust), trust was empirically supported as the most important determinants of user acceptance. This implies that users require trustworthiness from an Internet shopping site to be repeat visitors of an ISM. Providing a sense of safety and eliminating the anxiety of online shoppers in relation to privacy, security, delivery, and product returns are critically important conditions for acquiring repeat visitors. Hence, in addition to usefulness and ease of use as in TAM, trust should be a fundamental determinants of user acceptance in the context of internet shopping. Third, the user's ability on using an Internet shopping site played a moderating role. For users with low ability, ease of use was found to be a more important factors in deciding to reuse the shopping mall, whereas usefulness and trust had more effects on users with high ability. Applying the EML theory to these findings, we can suggest that experienced and knowledgeable ISM users tend to elaborate on such usefulness aspects as efficient and effective shopping performance and trust factors as ability, benevolence, integrity, and predictability of a shopping site before they become repeat visitors of the site. In contrast, novice users tend to rely on the low elaborating features, such as the perceived ease of use. The existence of moderating effects suggests the fact that different individuals evaluate an ISM from different perspectives. The expert users are more interested in the outcome of the visit(usefulness) and trustworthiness(trust) than those novice visitors. The latter evaluate the ISM in a more superficial manner focusing on the novelty of the site and on other instrumental beliefs(ease of use). This is consistent with the insights proposed by the Heuristic-Systematic model. According to the Heuristic-Systematic model. a users act on the principle of minimum effort. Thus, the user considers an ISM heuristically, focusing on those aspects that are easy to process and evaluate(ease of use). When the user has sufficient experience and skills, the user will change to systematic processing, where they will evaluate more complex aspects of the site(its usefulness and trustworthiness). This implies that an ISM has to provide a minimum level of ease of use to make it possible for a user to evaluate its usefulness and trustworthiness. Ease of use is a necessary but not sufficient condition for the acceptance and use of an ISM. Overall, the empirical results generally support the proposed model and identify the moderating effect of the effects of user ability. More detailed interpretations and implications of the findings are discussed. The limitations of this study are also discussed to provide directions for future research.

• 지능정보연구
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• 제19권4호
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• pp.123-132
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• 2013

최근 스마트 폰에 다양한 센서를 내장할 수 있게 되었고 스마트폰에 내장된 센서를 이용항 동작 인지에 관한 연구가 활발히 진행되고 있다. 스마트폰을 이용한 동작 인지는 노인 복지 지원이나 운동량 측정. 생활 패턴 분석, 운동 패턴 분석 등 다양한 분야에 활용될 수 있다. 하지만 스마트 폰에 내장된 센서를 이용하여 동작 인지를 하는 방법은 사용되는 센서의 수에 따라 단일 센서를 이용한 동작인지와 다중 센서를 이용한 동작인지로 나눌 수 있다. 단일 센서를 이용하는 경우 대부분 가속도 센서를 이용하기 때문에 배터리 부담은 줄지만 다양한 동작을 인지할 때에 특징(feature) 추출의 어려움과 동작 인지 정확도가 낮다는 문제점이 있다. 그리고 다중 센서를 이용하는 경우 대부분 가속도 센서와 중력센서를 사용하고 필요에 따라 다른 센서를 추가하여 동작인지를 수행하며 다양한 동작을 보다 높은 정확도로 인지할 수 있지만 다수의 센서를 사용하기 때문에 배터리 부담이 증가한다는 문제점이 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해 스마트 폰에 내장된 가속도 센서를 이용하여 다양한 동작을 높은 정확도로 인지하는 방법을 제안한다. 서로 다른 10가지의 동작을 높을 정확도로 인지하기 위해 원시 데이터로부터 17가지 특징을 추출하고 각 동작을 분류하기 위해 Ensemble of Nested Dichotomies 분류기를 사용하였다. Ensemble of Nested Dichotomies 분류기는 다중 클래스 문제를 다수의 이진 분류 문제로 변형하여 다중 클래스 문제를 해결하는 방법으로 서로 다른 Nested Dichotomy 분류기의 분류 결과를 통해 다중 클래스 문제를 해결하는 기법이다. Nested Dichotomy 분류기 학습에는 Random Forest 분류기를 사용하였다. 성능 평가를 위해 Decision Tree, k-Nearest Neighbors, Support Vector Machine과 비교 실험을 한 결과 Ensemble of Nested Dichotomies 분류기를 사용하여 동작 인지를 수행하는 것이 가장 높은 정확도를 보였다.

• Tuberculosis and Respiratory Diseases
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• 제45권5호
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• pp.962-974
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• 1998

연구배경: 최근 폐암은 전세계적으로 증가 추세에 놓여 있을 뿐 아니라 서구에서는 여성 폐암 환자의 비율이 크게 늘고 있으며 이미 폐암은 유럽과 미주에서 사망원인 1위의 암종으로 이미 우리 나라를 비롯하여 다른 여러 국가에서도 비슷한 경향을 보이고 있다. 원발성 폐암의 80%가 비소세포폐암으로 진행이 국소적인 폐암인 경우 수술적 제거가 주된 치료이나 이러한 양호한 경우에도 환자의 약 50% 만이 5년이상 생존할 수 있다. 확실히 비슷한 병기에도 불구하고 환자의 생존률은 현격한 차이를 보이고 있기 때문에 폐암의 분자학적, 생물학적 특정 등에 대한 연구가 진행되어 생존률을 보다 정확하게 예측하고 각각의 환자에 대한 보다 알맞는 치료 방법을 적용하기 위한 새로운 예후적 인자를 알려는 노력이 진행되고 있다. 앙은 세포의 증식과 함께 apoptotic 세포 소실의 감소에 의해 성장할 수 있다. 일반적으로 고형 종양은 성장과 세포의 손실은 종양의 전이, 분화, 죽음 등의 다양한 생물학적인 기전에 의하여 야기된다. 이중에 세포의 죽음은 면역학적 반응, 불가항력적인 미세환경의 상태 (세포의 괴사), 또는 apoptosis와 같은 유전자적인 조절에 의하여 생기게 된다. 암은 세포 주기의 증가로 인한 방법(종양 유전자의 활성도의 종가)과 세포 주기 진행억제의 감소(암억제 유전자의 소실), bcl-2의 과발현과 같은 antiapoptosis signal의 감소 및 bax의 감소 또는 p53의 돌연변이와 같은 proapoptosis signal의 감소 등을 야기하게 되는 유전자의 돌연변이에 의해 발생된다고 할 수 있다. 세포소실에 대한 변수에 대해 체계적인 연구가 거의 없지만 몇몇 단일 변수에 대한 연구가 진행되었다. 이에 저자들은 비소세포폐암에서 예후적 인자로서의 p53과 bcl-2의 발현이 환자의 예후에 어떠한 영향을 보이는지 알기 위해 본 연구를 시행하였다. 방 법: 1980년부터 1994 년 한양대학교 부속병원에서 비소세포폐암으로 진단된 후 술전 병기가 초기(병기 I-IIIa) 라고 판단되어 치료 목적으로 광법위 폐절제술을 시행받은 환자중 수술후 1 달이내에 수술의 합병증으로 사망한 예를 제외한 환자와 이들의 폐절제 조직 총 84예를 대상으로 하였는데 환자는 원발 폐암과 림프절에 대해 광범위 절제술(엽절제술 또는 전폐절제술)을 시행하였으며 환자는 술전에 아무런 치료 (방사선 또는 항암약제 치료)도 받지 않았고 술후에는 각각의 조직학적 병기에 따라 보조 치료를 받았다. 폐절제로 얻은 조직의 조직학적 특징은 WHO 표준 기준에 맞추었고 또한 환자의 조직병리학적 병기 판정은 TNM 병기 판정 기준에 맞추었다. 이와 같이 얻어진 이용하여 p53과 bcl-2 각각의 단클론 항체로 면역조직화학적 염색을 시행하였고 이의 발현과 환자의 생존률과의 연관성을 알아보았다. 결 과: p53과 bcl-2의 발현은 총 84예에서 시행하여 각각 47예 56.0%, 15예 17.9%의 발현율을 보였다. bcl-2의 발현군은 생존기간이 $64.23{\pm}10.73$달이었으나 음성군은 생존기간이 $35.28{\pm}4.39$달 (p=0.03)로 전체 환자의 생존과 bcl-2의 발현은 밀접한 연관을 보였고 cyclin D1은 양성 발현군의 생존 기간이 $22.76{\pm}3.50$개월, 음성 발현군의 생존기간이 $45.38{\pm}5.64$개월 (p=0.0515)로 생존율과의 상당한 통계적인 연관성의 가능성을 나타내었지만 p53 의 경우는 통계적 의의를 찾을 수 없었다(양성군의 생존기간 $34.71{\pm}6.12$ 달, 발현 음성군의 생존기간 $45.35{\pm}6.30$ 달, p=0.21). 결 론: 결론적으로 본 연구에서는 비소세포폐암에서 bcl-2의 발현은 양호한 예후 인자로 작용하였으며 p53의 발현은 비소세포폐암의 예후적인 인자로의 통계학적 의미를 찾을 수가 없었다. 또한 bcl-2의 발현과 p53 발현 사이에 역관계가 있다는 보고가 있어서 이의 연관성을 알아보았으나 생존율에 대한 bcl-2와 p53의 발현에서 일어날 수 있는 네가지 조합 ; bcl-2(+)/p53(+), bcl-2 (+)/p53(-), bcl-2(-)/p53 (+) 및 bcl(-)/p53(-) 사이에서 통계학적 의의를 발견하지 못하였다. 결론적으로 폐암의 발암과정은 어느 한 유전자 또는 인자에 의해 야기되는 단순한 과정이 아니고 여러 조절인자들의 복합적인 복잡, 다양한 상호간의 작용에 의해서 서로 영향을 주므로써 폐암의 발암과정의 중요한 기전이 된다고 생각되므로 보다 광범위한 연구가 필요하다고 사료된다.

• 한국산림과학회지
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• 제54권1호
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• pp.1-24
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• 1981

강원도(江原道)는 관광자원(觀光資源)이 풍부(豊富)하며 태백산맥(太白山脈)을 중심(中心)으로한 산악관광권(山岳觀光圈), 동해안(東海岸)의 해안관광권(海岸觀光圈), 내륙(內陸)의 호수관광권(湖水觀光圈)으로 구분(區分)하고 있다. 동해(東海)의 절경(絶景)을 배경(背景)으로 설악산(雪岳山)과 오태산(五台山)의 국립공원(國立公園)이 있다. 그리고 치악산(雉岳山)의 도립공원(道立公園)이 있다. 북한강상류수계(北漢江上流水系)에는 발전용(發電用)댐건설(建設)로 만수(滿水)된 인공호수(人工湖水)가 연좌(連坐)하고 있어 호수관광권(湖水觀光圈)으로 각광(脚光)을 받고 있다. 본(本) 논문(論文)에서도 강원도행정수도(江原道行政首都)이며 호반(湖畔)의 도시(都市)인 춘천(春川)을 중심(中心)으로 북한강상류수계(北漢江上流水系)에 연좌(連坐)하고 있는 호수단지주변(湖水團地周邊)의 관광자원(觀光資源)을 배경(背景)으로 하여 삼림(森林)의 풍경적시업방안(風景的施業方案)을 모색하고 있다. 본(本) 호수단지(湖水團地)는 하류(下流)로부터 상류(上流)로 향(向)하여 의암호(衣岩湖), 소양호(昭陽湖), 춘천호(春川湖), 파려호(破慮湖)가 자리잡고 있으며 이들 4개(個) 호수(湖水)의 면적(面積)은 $140.4km^2$ 총저수량(總貯水量)은 4,155백만(百萬)$m^3$이다. 그리고 발전량(發電量)은 41만(萬)KW의 시설(施設)을 갖추고 있다. 이들 호수(湖水)를 위적(囲績)하고 있는 삼림면적(森林面積)은 $1,208km^2$에 달(達)한다. 삼림(森林)은 행정적(行政的)으로 시업림(施業林)$745km^2$와 시업제한림(施業制限林) $463km^2$로 구분(區分)하고 있으며 시업제한림(施業制限林)은 개발제한구역(開發制限區域)과 자연환경보전지구내(自然環境保全地區內)에 있는 삼림(森林)과 보안림(保安林)으로 되어 있다. 개발제한구역내(開發制限區域內)에 있는 삼림(森林)은 춘천(春川)을 중심(中心)으로 반경(半徑) 10km이내(以內)에 있는 의암호주변삼림(衣岩湖周邊森林)이며 그 면적(面積)은 $177km^2$이다. 자연환경보전지구내(自然環境保全地區內)의 삼림(森林)은 소양호연안(昭陽湖沿岸)에서 2km의 가시권내(可視圈內)에 설정(設定)되어 있으며 그 면적(面積)은 $165km^2$이다. 보안림(保安林)은 각(各) 호수연안삼림(湖水沿岸森林)에 설정(設定)되어 있으며 입지적여건상(立地的與件上) 수원함양림(水源函養林)이 주종(主宗)이며 그 면적(面積)은 $121km^2$이다. 본(本) 호수단지권내(湖水團地圈內)에는 많은 각승지(各勝地)와 유원지(遊園地) 그리고 문화재(文化財)와 유적지(遺蹟地)가 있어 호수(湖水)와 삼림(森林)과 같이 귀중(貴重)한 관광자원(觀光資源)으로 부상(浮上)되고 있다. 본(本) 호수단지주변삼림(湖水團地周邊森林)은 I~II영급(令級)의 유령림(幼令林)이 전체삼림(全體森林)의 70%를 점(點)하고 있어 ha당(當)축적(蓄積)은 $15m^3$로 탐약(貪弱)하다. 침엽수림(針葉樹林), 활엽수림(濶葉樹林), 혼효림(混淆林)의 면적비율(面積比率)은 35:37:28로 활엽수림(濶葉樹林)의 면적(面積)이 약천(若千) 우위(優位)를 점(點)하고 있다. 소유형태(所有形態)는 국유림(國有林), 도유림(道有林), 군유림(郡有林), 사유림(私有林)으로 되어 있으며 그 비율(比率)은 36:14:5:45로 사유림(私有林)이 약절반(約切半)을 점(點)하고 다음이 국유림(國有林), 도유림(道有林), 군유림(郡有林)의 순(順)으로 되어 있다. 지질(地質)은 모암(母岩)이 화강암(花岡岩) 또는 편마암계(片麻岩系)로서 풍화성(風化性)이 강(强)하고 표토층(表土層)이 척박(瘠薄)함으로 임지비배문제(林地肥培問題)를 염두(念頭)에 두어야 한다. 이상(以上)의 여건(與件)을 토태(土台)로 삼림(森林)의 풍경적시업(風景的施業)의 기본방향(基本方向)을 제시(提示)하면 다음과 같다. 1) 현재(現在) 임분(林分)은 유령림(幼令林)이 대부분(大部分)이고 임지(林地)가 척박(瘠薄)함으로 임지비배(林地肥培)와 임목무육(林木撫育)에 주력(注力)하여 장령림(壯令林)의 경지(境地)로 유도(誘導)할 것. 2) 황폐성미립목지(荒廢性未立木地)와 임간라지(林間裸地)에는 속성수(速成樹)인 리기다소나무, 오리나무 등(等)은 식재(植栽)하여 조속(早速)히 피복녹화(被覆綠化) 시킬 것. 3)계곡부(溪谷部)로서 습윤(濕潤)하고 지미(地味)가 비교적(比較的) 양호(良好)한 라지(裸地)에는 잣나무, 낙엽송, 전나무 등(等)을 식재(植栽)하여 교림(喬林)으로 육성(育成)할 것. 4) 현재(現在) 사유림(私有林)의 침엽수림(針葉樹林)은 적송(赤松)이 주체(主體)가 되어 있다. 적송(赤松)은 양수(陽樹)로서 수원함양기능(水源函養機能)이 적은 위에 현재(現在) 솔잎혹파리의 피해(被害)를 입고 있어 수종갱신(樹種更新)이 불가피(不可避)하다. 그러므로 계곡부(溪谷部)부터 잣나무, 전나무, 가문비나무, 솔송나무 등(等)을 식재(植栽)하에 점차(漸次) 음성(陰性) 침엽수림(針葉樹林)으로 대체(代替)케 할 것. 5) 현재(現在) 활엽수림(濶葉樹林)은 재질면(材質面)에 있어서나 풍치면(風致面)에 있어서 가치성(價値性)이 저렬(低劣)한 잡목(雜木), 관목(灌木) 등(等)이 많으므로 점차(漸次) 이를 제거(除去)하고 참나무, 단풍나무, 물푸레나무, 자작나무, 가래나무등(等)으로 대체(代替)케 할 것. 6) 주변(周邊) 산록부(山麓部)에는 벚나무, 수양버들, 은사시나무, 후박나무, 은행나무, 향나무, 밤나무, 살구나무, 등(等)의 관상수(觀賞樹)를 조화(調和)있게 식재(殖財)할 것. 7) 활엽수림(濶葉樹林)의 갱신(更新)을 중림형(中林型)으로 유도(誘導)하여 상하이단(上下二段)의 임관형(林冠型)의 미(美)를 조성(造成)하는 구역(區域)과 왜림형(矮林型)을 조리(調利)있게 배열(配列)하는 방안(方案)을 모색할 것. 8) 침엽수림(針葉樹林)의 갱신(更新)은 택벌작업(擇伐作業) 또는 산벌작업(傘伐作業)에 의(依)해 풍치보전(風致保全)을 기(期)할 것. 9) 혼효림(混淆林)은 상목(上木)은 침엽수(針葉樹)를 하목(下木)은 활엽수(濶葉樹)로 하는 중림형(中林型)의 풍치(風致)를 보존(保存)토록 할 것. 요(要)컨대 호수(湖水)의 우아(優雅)한 여성미(女性美)와 삼림(森林)의 호장웅대(豪壯雄大)한 남성미(男性美)가 조화(調和)되어 자연(自然)의 심오(深奧)한 신비성(神秘性)을 간직하는데 역점(力點)을 두어 궁극적(窮極的)으로는 삼림(森林)을 배경(背景)으로한 호수관광권(湖水觀光圈)의 면모(面貌)를 갖추는데 초점(焦點)을 둘 것이다.

• 대한방사선치료학회지
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• 제26권2호
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• pp.257-264
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• 2014

목 적 : 고에너지 광자선을 이용한 방사선치료 시 발생되는 광중성자는 치료대상인 종양 주위의 인접한 정상조직에서 2차적인 암의 발생에 기인 될 수 있다고 알려져 있다. 본 연구에서는 방사선치료계획 시에 고려할 수 있는 변수 중 치료방법, 선속평탄여과판, 선량률, 갠트리 각도들을 변환시켰을 때 발생된 광중성자의 선량 변화를 비교 분석하였다. 대상 및 방법 : 실험에는 TrueBeam $ST{\time}TM$(Ver.1.5, Varian, USA)치료기를 사용하였다. 광중성자 측정 장비는 조직등가비례계수기(Tissue Equivalent Proportional Counter : TEPC)인 KTEPC를 이용하였으며, 치료대의 세로 방향으로 조사야 중앙 하단 6cm 지점에서 측정을 실시하였다. 치료방법, 선속평탄여과판의 사용유무, 선량율에 따른 광중성자 선량의 차이를 평가하기 위하여 모든 환자에 대하여 전산화치료계획시스템(Eclipse Ver 10.0, Varian, USA)으로 방사선치료계획을 각각 수립하였다. 치료방법으로는 세기변조방사선치료와 용적변조회전방사선치료로 구분하였으며, 선량율은 400MU/min, 1,200MU/min 및 2,400MU/min에 따른 차이를 평가하였다. 또한 방사선의 입사방향에 따른 광중성자 선량을 측정하였다. 결 과 : 치료방법의 차이에 따라 세기변조방사선치료와 용적변조회전방사선치료로 조사하였을 때 산란 광중성자 평균선량은 각각 $449.7{\mu}Sv$, $2940.7{\mu}Sv$로 측정되었다. 선속평탄여과판의 사용 유무에 따라 Flattening Filter(FF)모드와 Flattening Filter Free(FFF)모드에서의 산란 광중성자 평균선량은 $2940.7{\mu}Sv$, $232.0{\mu}Sv$로 측정되었다. 400, 1200, 2400 MU/min으로 선량률을 변환시켜 조사하였을 때 CASE I은 $3242.5{\mu}Sv$, $3189.4{\mu}Sv$, $3191.2{\mu}Sv$로, CASE II는 $3493.2{\mu}Sv$, $3482.6{\mu}Sv$, $3477.2{\mu}Sv$로, 그리고 CASE III에서 $4592.2{\mu}Sv$, $4580.0{\mu}Sv$, $4542.3{\mu}Sv$로 측정 되었다. $0^{\circ}$부터 $315^{\circ}$까지 $45^{\circ}$간격으로 갠트리 각도를 변환시켰을 때 산란 광중성자 선량은 10MV 광자선에 대하여 최소 $3.2{\mu}Sv$, 최대 $14.7{\mu}Sv$이었으며, 갠트리 각도가 $180^{\circ}$일 때 가장 높게 나타났다. 15MV 광자선의 경우 최소 $369.6{\mu}Sv$ 최대 $448.0{\mu}Sv$이었으며, 역시 갠트리 각도가 $180^{\circ}$일 때 가장 높게 측정되었다. 결 론 : 치료방법의 차이에 따른 실험은 용적변조회전방사선치료가 세기변조방사선치료 보다 산란된 광중성자 선량이 측정점에서 평균 6.5배 높게 측정되었다. 선속평탄여과판의 사용 차이에 따른 실험에서 선속평탄여과판을 사용하였을 때 12.7배 높게 측정되었다. 선량률을 변환에 따른 차이는 큰 차이를 보이지 않았다. 갠트리 각도에 따른 산란 광중성자 선량 측정에서는 광자선이 치료대를 지나는 각도인 $135^{\circ}$, $180^{\circ}$, $225^{\circ}$에서 산란 광중성자 선량이 증가하는 것을 확인할 수 있었다. TrueBeam $ST{\time}TM$을 이용한 FFF 모드와 세기변조방사선치료를 한 경우 산란 광중성자가 적게 발생한다는 것을 확인할 수 있었다. 지속적으로 더 많은 변수에 대한 실험을 계획하고 광중성자 측정에 대한 평가를 통하여, 보다 환자들에게 안전한 방사선치료에 기여할 수 있을 것으로 사료된다.