• Progress in Medical Physics
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• v.23 no.1
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• pp.15-25
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• 2012

The aim of this study is to evaluate plan quality and dose accuracy for Volumetric Modulated Arc Therapy (VMAT) on the TG-119 and is to investigate the effects on variation of the selectable optimization parameters of VMAT. VMAT treatment planning was implemented on a Varian iX linear accelerator with ARIA record and verify system (Varian Mecical System Palo Alto, CA) and Oncentra MasterPlan treatment planning system (Nucletron BV, Veenendaal, Netherlands). Plan quality and dosimetric accuracy were evaluated by effect of varying a number of arc, gantry spacing and delivery time for the test geometries provided in TG-119. Plan quality for the target and OAR was evaluated by the mean value and the standard deviation of the Dose Volume Histograms (DVHs). The ionization chamber and $Delta^{4PT}$ bi-planar diode array were used for the dose evaluation. For treatment planning evaluation, all structure sets closed to the goals in the case of single arc, except for the C-shape (hard), and all structure sets achieved the goals in the case of dual arc, except for C-shape (hard). For the variation of a number of arc, the simple structure such as a prostate did not have the difference between single arc and dual arc, whereas the complex structure such as a head and neck showed a superior result in the case of dual arc. The dose distribution with gantry spacing of $4^{\circ}$ was shown better plan quality than the gantry spacing of $6^{\circ}$, but was similar results compared with gantry spacing of $2^{\circ}$. For the verification of dose accuracy with single arc and dual arc, the mean value of a relative error between measured and calculated value were within 3% and 4% for point dose and confidence limit values, respectively. For the verification on dose accuracy with the gantry intervals of $2^{\circ}$, $4^{\circ}$ and $6^{\circ}$, the mean values of relative error were within 3% and 5% for point dose and confidence limit values, respectively. In the verification of dose distribution with $Delta^{4PT}$ bi-planar diode array, gamma passing rate was $98.72{\pm}1.52%$ and $98.3{\pm}1.5%$ for single arc and dual arc, respectively. The confidence limit values were within 4%. The smaller the gantry spacing, the more accuracy results were shown. In this study, we performed the VMAT QA based on TG-119 procedure, and demonstrated that all structure sets were satisfied with acceptance criteria. And also, the results for the selective optimization variables informed the importance of selection for the suitable variables according to the clinical cases.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.109-131
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• 2014

As the demand of nuclear power plant equipment is continuously growing worldwide, the importance of handling nuclear strategic materials is also increasing. While the number of cases submitted for the exports of nuclear-power commodity and technology is dramatically increasing, preadjudication (or prescreening to be simple) of strategic materials has been done so far by experts of a long-time experience and extensive field knowledge. However, there is severe shortage of experts in this domain, not to mention that it takes a long time to develop an expert. Because human experts must manually evaluate all the documents submitted for export permission, the current practice of nuclear material export is neither time-efficient nor cost-effective. Toward alleviating the problem of relying on costly human experts only, our research proposes a new system designed to help field experts make their decisions more effectively and efficiently. The proposed system is built upon case-based reasoning, which in essence extracts key features from the existing cases, compares the features with the features of a new case, and derives a solution for the new case by referencing similar cases and their solutions. Our research proposes a framework of case-based reasoning system, designs a case-based reasoning system for the control of nuclear material exports, and evaluates the performance of alternative keyword extraction methods (full automatic, full manual, and semi-automatic). A keyword extraction method is an essential component of the case-based reasoning system as it is used to extract key features of the cases. The full automatic method was conducted using TF-IDF, which is a widely used de facto standard method for representative keyword extraction in text mining. TF (Term Frequency) is based on the frequency count of the term within a document, showing how important the term is within a document while IDF (Inverted Document Frequency) is based on the infrequency of the term within a document set, showing how uniquely the term represents the document. The results show that the semi-automatic approach, which is based on the collaboration of machine and human, is the most effective solution regardless of whether the human is a field expert or a student who majors in nuclear engineering. Moreover, we propose a new approach of computing nuclear document similarity along with a new framework of document analysis. The proposed algorithm of nuclear document similarity considers both document-to-document similarity (${\alpha}$) and document-to-nuclear system similarity (${\beta}$), in order to derive the final score (${\gamma}$) for the decision of whether the presented case is of strategic material or not. The final score (${\gamma}$) represents a document similarity between the past cases and the new case. The score is induced by not only exploiting conventional TF-IDF, but utilizing a nuclear system similarity score, which takes the context of nuclear system domain into account. Finally, the system retrieves top-3 documents stored in the case base that are considered as the most similar cases with regard to the new case, and provides them with the degree of credibility. With this final score and the credibility score, it becomes easier for a user to see which documents in the case base are more worthy of looking up so that the user can make a proper decision with relatively lower cost. The evaluation of the system has been conducted by developing a prototype and testing with field data. The system workflows and outcomes have been verified by the field experts. This research is expected to contribute the growth of knowledge service industry by proposing a new system that can effectively reduce the burden of relying on costly human experts for the export control of nuclear materials and that can be considered as a meaningful example of knowledge service application.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.403-425
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• 2015

The Chicago Convention and Annexes have become the basis of aviation safety regulations for every contracting state. Generally, the State's aviation safety regulations refer to the Standards and Recommended Practices(SARPs) provided in the Annexes of the Chicago Convention. In order to properly reflect international aviation safety regulations, constant studies of the aviation fields are of paramount importance. This Paper is intended to identify the main differences between korean and foreign regulation and suggest a few amendment proposals on Mixed-fleet Flying(at or more two aircraft type operation) of flight crew. Comparing with these regulations, the korean regulations and implementations have some insufficiency points. I suggest some amendment proposals of korean regulations concerning Mixed-fleet Flying that flight crew operate aircraft of different types. Basically an operator shall not assign a pilot-in-command or a co-pilot to operate at the flight controls of a type of airplane during take-off and landing unless that pilot has operated the flight controls during at least three take-offs and landings within the preceding 90 days on the same type of airplane or in a flight simulator. Also, flight crew members are familiarized with the significant differences in equipment and/or procedures between concurrently operated types. An operator shall ensure that piloting technique and the ability to execute emergency procedures is checked in such a way as to demonstrate the pilot's competence on each type or variant of a type of airplane. Proficiency check shall be performed periodically. When an operator schedules flight crew on different types of airplanes with similar characteristics in terms of operating procedures, systems and handling, the State shall decide the requirements for each type of airplane can be combined. In conclusion, it is necessary for flight crew members to remain concurrently qualified to operate multiple types. The operator shall have a program to include, as a minimum, required differences training between types and qualification to maintain currency on each type. If the Operator utilizes flight crew members to concurrently operate aircraft of different types, the operator shall have qualification processes approved or accepted by the State. If applicable, the qualification curriculum as defined in the operator's Advanced Qualification Program could be applied. Flight crew members are familiarized with the significant differences in equipment and/or procedures between concurrently operated types. The difference among different types of airpcrafts decrease and standards for these airpcrafts can be applied increasingly because function and performance have been improved by aircraft manufacture company in accordance to basic aircraft system in terms of developing new aircrafts for flight standard procedure and safety of flight. Also, it becomes more necessary for flight crews to control multi aircraft types due to various aviation business and activation of leisure business. Nevertheless, in terms of flight crew training and qualification program, there are no regulations in Korea to be applied to new aircraft types differently in accordance with different levels. In addition, it has no choice different programs based on different levels because there are not provisions to restrict or limit and specific standards to operate at or more than two aircraft types for flight safety. Therefore the aviation authority introduce Flight Standardization and/or Operational Evaluation Board in order to analysis differences among aircraft types. In addition to that, the aviation authority should also improve standard flight evaluation and qualification system among different aircraft types for flight crews to apply reasonable training and qualification efficiently. For all the issue mentioned above, I have studied the ICAO SARPs and some state's regulation concerning operating aircraft of different types(Mixed-fleet flying), and suggested some proposals on the different aircraft type operation as an example of comprehensive problem solving. I hope that this paper is 1) to help understanding about the international issue, 2) to help the improvement of korean aviation regulations, 3) to help compliance with international standards and to contribute to the promotion of aviation safety, in addition.

• Progress in Medical Physics
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• v.25 no.2
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• pp.79-88
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• 2014

The dose distributions within the real volumes of tumor targets and critical organs during internal target volume-based intensity-modulated radiation therapy (ITV-IMRT) for liver cancer were recalculated by applying the effects of actual respiratory organ motion, and the dosimetric features were analyzed through comparison with gating IMRT (Gate-IMRT) plan results. The ITV was created using MIM software, and a moving phantom was used to simulate respiratory motion. The doses were recalculated with a 3 dose-volume histogram (3DVH) program based on the per-field data measured with a MapCHECK2 2-dimensional diode detector array. Although a sufficient prescription dose covered the PTV during ITV-IMRT delivery, the dose homogeneity in the PTV was inferior to that with the Gate-IMRT plan. We confirmed that there were higher doses to the organs-at-risk (OARs) with ITV-IMRT, as expected when using an enlarged field, but the increased dose to the spinal cord was not significant and the increased doses to the liver and kidney could be considered as minor when the reinforced constraints were applied during IMRT plan optimization. Because the Gate-IMRT method also has disadvantages such as unsuspected dosimetric variations when applying the gating system and an increased treatment time, it is better to perform a prior analysis of the patient's respiratory condition and the importance and fulfillment of the IMRT plan dose constraints in order to select an optimal IMRT method with which to correct the respiratory organ motional effect.

• Journal of Hospice and Palliative Care
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• v.9 no.2
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• pp.67-76
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• 2006

Purpose: The purpose of this study was to develop education program for physicians who work at hospice palliative care settings in Korea, to practice abridged education program extracted from the full contents of the proposed education, and to improve the quality of hospice palliative care service. Methods: To develop the education program, questionnaire for hospice education need assessment (total 79 items) was distributed to 125 organizations practicing hospice service via mail and the data was collected from 1 Sep. to 10 Oct. 2004. Another questionnaire for hospice education importance assessment was asked to the palliative specialists from Sep. 23 to 17 Oct. 2004. Based on the analysis of the questionnaires, and reviewing various references and actual hospice palliative education programs of other countries, the education programs were developed. Results: Ore-day-Hospice education 2004 was conducted based on the suggested education program, and it was practiced four times on a national basis (2 times in Seoul, and once in Busan and Gwangju, respectively). 47 physicians attended the education program. The education program lasted about 7 hours, comprising 5 hours of common lectures for all attendants regardless of their professions and 2 hours of specific seminar for physicians only. Attendants positively responded to the contents of the education program. But they pointed out that the program should be offered on weekday and it should be more in-depth and more discussion based lesson. Conclusion: The suggested education program was not fully conducted yet. After practicing the abridged education program, more in-depth and discussion oriented rather than lecture-based education were suggested. It may be argued that the proposed education, which requires much longer period education, should also reflect the evaluation of the 1-day education program to successfully implement the proposed education program.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.1-24
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• 2003

This study was done to compile 104 experimental theses which are related to the antitumor and immuno-activating therapies between February 1990 through February 2002. Master's and doctoral theses were dassified by schools, degrees, materials, effects, experimental methods of antitumor and immunoactivity, and results. The following results were obtained from this study : 1. Classifying the theses by the school, 34.6% were presented by Daejeon University, 29.8% by Kyung-hee University and 11.5% by Won-kwang University. Of all theses, 51.0% were aimed for the doctoral degree and 43.3% were for the master's degree. All of three universities have their own cancer centers. 2. Classifying the theses by herb materials, complex prescription accounted for 60.3%, single herb accounted for 24.8% and herbal acupuncture accounted for 14.2%. Considering the key principles of the traditional medicine, complex prescription was much more thoroughly studied than single herb prescription. The results showed that the complex prescription had both antitumor activity and immuno-activating activity, which might reflects on multi-activation mechanisms by complex components. 3. Classifying the theses by the efficacy of herbs examined, in single herb, invigorating spleen and supplementing was 35.5%, expelling toxin and cooling was 29.0%, activating blood flow and removing blood stasis was 12.9%. In herbal acupuncture, invigorating spleen and supplementing was 52.9%, expelling toxin and cooling was 29.4%. In complex prescription, pathogen-free status was 41.9%, strengthening healthy qi to eliminate pathogen was 35.5%, strengthening healthy qi was 22.6%. It is presumed that the antitumor and immunoactivating therapy based on syndrome differentiation is the best way to develop oriental oncology. 4. Classifying the theses by antitumor experiments, cytotoxic effect was 48.1 %, survival time was 48.1 % and change of tumor size was 42.3%. Survival rate was not necessarily correlated with cytotoxicity. These data reflect the characteristic, wholistic nature of the oriental medicine which is based on BRM (biological response modifier). 5. Classifying the theses by immunoactivating experiments, hemolysin titer was 51.0%, hemagglutinin titer was 46.2% and NK cell's activity was 44.2%. In the future studies, an effort to elucidate specific molecular and cellular mechanisms of cytokine production in the body would be crucial. 6. Classifying the theses according to the data in terms of antitumor activity, 50% was evaluated good, 24.0% was excellent, and 15.5% have no effect. In an evaluation of immuno-activating activity, 35.9% was excellent and 18.0% showed a little effect. The index point, as described here, may helps to use experimental data for clinical trials. Changes in index points by varying dosage implicate the importance of oriental medical theory for prescription. 7. In 167 materials, IIP (immunoactivating index point, mean : 3.12±0.07) was significantly higher than AIP(antitumor index point, mean : 2.83±0.07). These data demonstrate that the effect of herb medicine on tumor activity depends more on immunoactivating activity than antitumor activity. This further implies that the development of herbal antitumor drugs must be preceded by the mechanistic understanding of immunoactivating effect. 8. After medline-searching tumor and herb-related articles from NCBI web site, we conclude that most of the studies are primarily focused on biomolecular mechanisms and/or pathways. Henceforth, we need to define the biomolecular mechanisms and/or pathways affected by herbs or complicated prescriptions. 9. Therefore, the most important point of oriental medical oncology is to conned between experimental results and clinical trials. For the public application of herbal therapy to cancer, it is critical to present the data to mass media. 10. To develop the relationship of experimental results and clinical trials, university's cancer clinic must have a long-range plan related to the university laboratories and, at the same time, a regular consortium for this relationship is imperative. 11. After all these efforts, a new type herbal medicine for cancer therapy which is to take care of the long-term administering and safety problem must be developed. Then, it would be expected that anti-tumor herbal acupuncture can improve clinical symptoms and quality of life (QOL) for cancer patients. 12. Finally, oriental medical cancer center must be constructed in NCC (National Cancer Center) or government agency for the development of oriental medical oncology which has international competitive power.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.83-87
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• 2011

Purpose: Recently in diagnostics area PET/CT is using a variety of areas including oncology, as well as in cardiology, neurology, etc. While increasing in the importance of PET/CT, there are various researches in the image quality related to reconstruction method. We compared and tested Iterative 2D Reconstruction Method with True X Reconstruction method by Siemens through phantom experiment, so we can see increasing of clinical usefulness of PET/CT. Materials and Methods: We measured contrast ratio and FWHM due to evaluating images on dose and experiment using Biograph 40 True Point PET/CT (Siemens, Germany). Getting a result of contrast ratio and FWHM, we used NEMA IEC PET body phantom (Data Spectrum Corp.) and capillary tube. We used the current TrueX and the previous Iterative 2D algorithm for all images which have 10 minutes long. Also, a clinical suitability of parameter for Iterative 2D and a recommended parameter by Siemens for True X are applied to the experiment. Results: We tested FWHM using capillary tube. As a result, TrueX was less than Iterative 2D. Also, the differences of FWHM get bigger in low dose. On the other hand, we tested contrasts ratio using NEMA IEC PET body phantom. As a result, TrueX was better aspect than Iterative 2D. However, there was no difference in dose. Conclusion: In this experiment, TrueX get higher results of contrast ratio and spatial resolution than Itertive 2D through experiment. Also, in the reconstruction result through TrueX, TrueX had better aspect of resolution than Iterative 2D in low dose. However, contrast ratio had no specific difference. In other words, TrueX reconstruction method in PET/CT had higher clinical value in use because TrueX can reduce exposure of patient and had a better quality of screen.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.139-160
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• 2017

Technology commercialization creates effective economic value by linking the company's R & D processes and outputs to the market. This technology commercialization is important in that a company can retain and maintain a sustained competitive advantage. In order for a specific technology to be commercialized, it goes through the stage of technical planning, technology research and development, and commercialization. This process involves a lot of time and money. Therefore, the duration and cost of technology commercialization are important decision information for determining the market entry strategy. In addition, it is more important information for a technology investor to rationally evaluate the technology value. In this way, it is very important to scientifically estimate the duration and cost of the technology commercialization. However, research on technology commercialization is insufficient and related methodology are lacking. In this study, we propose an evaluation model that can estimate the duration and cost of R & D technology commercialization for small and medium-sized enterprises. To accomplish this, this study collected the public data of the National Science & Technology Information Service (NTIS) and the survey data provided by the Small and Medium Business Administration. Also this study will develop the estimation model of commercialization duration and cost of R&D performance on using these data based on the market approach, one of the technology valuation methods. Specifically, this study defined the process of commercialization as consisting of development planning, development progress, and commercialization. We collected the data from the NTIS database and the survey of SMEs technical statistics of the Small and Medium Business Administration. We derived the key variables such as stage-wise R&D costs and duration, the factors of the technology itself, the factors of the technology development, and the environmental factors. At first, given data, we estimates the costs and duration in each technology readiness level (basic research, applied research, development research, prototype production, commercialization), for each industry classification. Then, we developed and verified the research model of each industry classification. The results of this study can be summarized as follows. Firstly, it is reflected in the technology valuation model and can be used to estimate the objective economic value of technology. The duration and the cost from the technology development stage to the commercialization stage is a critical factor that has a great influence on the amount of money to discount the future sales from the technology. The results of this study can contribute to more reliable technology valuation because it estimates the commercialization duration and cost scientifically based on past data. Secondly, we have verified models of various fields such as statistical model and data mining model. The statistical model helps us to find the important factors to estimate the duration and cost of technology Commercialization, and the data mining model gives us the rules or algorithms to be applied to an advanced technology valuation system. Finally, this study reaffirms the importance of commercialization costs and durations, which has not been actively studied in previous studies. The results confirm the significant factors to affect the commercialization costs and duration, furthermore the factors are different depending on industry classification. Practically, the results of this study can be reflected in the technology valuation system, which can be provided by national research institutes and R & D staff to provide sophisticated technology valuation. The relevant logic or algorithm of the research result can be implemented independently so that it can be directly reflected in the system, so researchers can use it practically immediately. In conclusion, the results of this study can be a great contribution not only to the theoretical contributions but also to the practical ones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.73-87
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• 2018

A variety of micro meteorological variables such as air temperature, wind, solar radiation and latent heat at Gwangneung forests (conifer and broadleaved forests) and AWS (Automated Weather Station) of Pocheon urban area were used to quantify the air temperature reduction effect of forests, which is considered to be an eco-friendly solution for reducing the urban heat island intensity during summer. In June, July and August of 2016 and 2017, the average maximum air temperature differences between above and below canopy of forests, and between the forests and urban areas were $-1.9^{\circ}C$ and $-3.4^{\circ}C$ respectively, and they occurred at 17:00. However, there was no difference between conifer and broadleaved forests. The effect of air temperature reduction by the forests was positively correlated with accumulated evapotranspiration and solar radiation from 14:00 to 17:00 and showed a negative correlation with wind speed. We have developed a model to quantify the effect of air temperature reduction by forests using these variables. The nighttime air temperature reduction effect by forests was due to the generation of cold air from radiative cooling and the air temperature inversion phenomenon that occurs when the generated cold air moves down the side of mountain. The model was evaluated in Seoul by using 28 AWSs. The evaluation shows that the air temperature of each district in Seoul was negatively correlated with the area and size of the surrounding tall vegetation that drives vegetation evapotranspiration during the day. During the night, however, the size of the surrounding tall vegetation and the elevations of nearby mountains were the main influencing factors on the air temperature. Our research emphasizes the importance of the establishment and management of urban forests and the composition of wind roads from mountains for urban air temperature reduction.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.4
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• pp.166-175
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• 2015

Nowadays, in the European countries, landscape is spoken of its importance as often as environment, by those who are engaged in such fields as politics, administration, research and civil society. In Korea, while recognizing such an international trend, academics and administrators have made a series of efforts to reflect landscape concept on a variety of policies. However, it is recognized that the effects of these policies have not been satisfactory. Under these circumstances, this paper aims to examine the complex values and multiple meanings in the landscape, which have been discussed by landscape experts in the European countries. Then, it aims to the explore the future direction of policy and research on the landscape to be pursued in Korea, where there is relatively less interest in the issues of landscape. It is argued that landscape should be approached and understood from a holistic perspective, because it is a very complex concept with multiple meanings that have been coined differently depending on the situation. All the academic fields, involved in the landscape research, should try in co-operation to develop the comprehensive approach rather than the inter- and multi-disciplinary approach to the landscape study. In Korea, moreover, it is also necessary in the legislation to recognize the fact that degradation and retreat in the quality of landscape would make a negative effect on the quality of human daily life. Natural and cultural heritages contained in the rural landscape are also now in danger of disappearing. These heritages, therefore, should become an important subject for research and policy on landscape before the countryside is completely evacuated after the aging population die out. To make this happen, it is very urgent that evaluation and classification of landscape character should be undertaken from the holistic perspective, which is equipped with a methodology overcoming as well as encompassing the boundaries of academic fields. It is also equally very urgent that education on landscape should be provided to the politicians, citizens and students as well as the officials dealing with landscape matters. Finally, government should strive to make the landscape concept penetrate deeply as well as widely into the spatial planning and legislation process while designing and implementing a comprehensive landscape policy at the national level.