• Earthquakes and Structures
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• v.14 no.3
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• pp.241-248
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• 2018

To study the mechanical properties of joints in ancient timber buildings in depth, the force mechanism of the through-tenon joints was analyzed, also the theoretical formulas of the moment-rotation angles of the joints with different loosening degrees were deduced. To validate the rationality of the theoretical calculation formulas, six joint models with 1/3.2 scale ratio, including one intact joint and five loosening joints, were fabricated and tested under cyclic loading. The specimens underwent the elastic stage, the plastic stage and the destructive stage, respectively. At the same time, the moment-rotation backbone curves of the tenon joints with different looseness were obtained, and the theoretical calculation results were validated when compared with the experimental results. The results show that the rotational moment and the initial rotational stiffness of the tenon joints increase gradually with the increase of the friction coefficient. The increase of the tenon section height can effectively improve the bearing capacity of the through-tenon joints. As the friction coefficient of the wood and the insertion length of the tension increase, the embedment length goes up, whereas it decreases with the increase of section height. With the increase of the looseness, the bearing capacity of the joint is reduced gradually.

• Herbal Formula Science
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• v.16 no.1
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• pp.29-38
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• 2008

Background and Objectives : There are four kinds of formulas for invigorating the kidney to cure its asthenic syndrome based on the types of preparation formulas : Boshintang, Boshinhwan, Boshinsan, and Boshingaeng. There are 16 kinds of Boshintang, 28 kinds of Boshinhwan, 3 kinds of Boshinsan, and one kind of Boshingaeng. Combination of herbal medicines, carried out in formulas for invigorating the kidney, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Boshintang for curing the asthenic syndrome of kidney through analyzing the component medicines and combination principles of Hyeongok's Boshintang, and furthermore, maximizing the clinical use of Boshintang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Boshintang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Boshintang is an even prescription, composed of 6 kinds of ingredients : No.1 Fructus Lycii (3don;11.25g), No.2 Radix Polygoni Multiflori (1don:3.75g), No.3 Sarcucarpium Corni (1don), No.4 Fructus Schisandrae (1don), No.5 Rhizoma Anemarrhenae (5poon: 1.875g), and No.6 Cortex Phellodendri (5poon) Results : There are three methods for curing the asthenic syndrome of kidney according to the five elements doctrine : invigorating the kidney, invigorating the lung and purging the spleen. First, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your kidney. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the bitter taste and the cold property invigorate the kidney. In the case of taste invigoration, two herbal medicines with bitter taste, Fructus Lycii and Radix Polygoni Multiflori, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herbal medicines with the cold property, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your lung which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the lung, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the sour taste and the cool property invigorate the lung. Therefore, it is important to use sour herbal medicines for taste invigoration and cool ones for property invigoration. Both bitter and cool herbal medicines, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the kidney, you need to purge your spleen which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the spleen, which include taste and property purgation according to the theory for properties and tastes of herbal medicines. Taste purgation means to purge the spleen with bitter taste and property purgation to purge the spleen with cool property. Therefore, it is important to use bitter herbal medicines for taste purgation and cool ones for property purgation. Both bitter and cool herbal medicines, Rhizome Anemarrhenae and Cortex Phellodendri. were combined to purge the spleen and invigorate the kidney. In addition, Rhizome Anemarrhenae and Cortex Phellodendri are combined as dispatcher herbal medicine, reinforcing the kidney energy. Conclusions : First, to cure the asthenic syndrome of the kidney, the methods of invigorating the kidney and the lung, and purging the spleen should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Boshintang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Herbal Formula Science
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• v.16 no.2
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• pp.91-100
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• 2008

Background and Objectives : There are three kinds of formulas for purging the kidney to cure its sthenic syndrome based on the types of preparation formulas : Sashintang, Sashinhwan and Sashinsan. There are 4 kinds of Sashintang, 1 kind of Sashinhwan and 1 kind of Sashinsan. Combination of herbal medicines, carried out in formulas for purging the kidney, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Pyeongshintang for curing the sthenic syndrome of kidney through analyzing the component medicines and combination principles of Hyeongok's Pyeongshintang, and furthermore, maximizing the clinical use of Pyeongshintang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Pyeongshintang based on the theory for properties and tastes of herbal medicines from the "Yellow Emperor's Canon of Internal Medicine", the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Pyeongshintang is an odd prescription, composed of 7 kinds of ingredients : No.1 Rhizoma Alismatis (2don;7.5g), No.2 Poria (1don;3.75g), No.3 Radix Paeoniae Alba (1don), No.4 Fructus Chaenomelis (1don), No.5 Polyporus (1don), No.6 Cortex Cinnamomi (1don), and No.7 Radix Glycyrrhizae (1don) Results : There are three methods for curing the sthenic syndrome of kidney according to the five elements doctrine : purging the kidney, purging the liver and invigorating the spleen. First, if you suffer from the sthenic syndrome of the kidney, you need to purge your kidney. There are two available methods, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each imply the salty taste and the hot property purge the kidney. In the case of taste purgation, two herbal medicines with salty taste, Rhizoma Alismatis and Poria, are combined into the principal and assistant herbal medicine, respectively. For property purgation, two herbal medicines with the hot property, Polyporus and Cortex Cinnamomi, are combined into adjuvant herbal medicines. Secondly, if you suffer from the sthenic syndrome of the kidney, you need to purge your liver which is child in the mother-child relationship in inter-promotion among the five elements. There are two methods to purge the liver, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each mean the sour taste and the cool property purge the liver. Therefore, it is important to use sour herbal medicines for taste purgation and cool ones for property purgation. Both sour and cool herbal medicines, Radix Paeoniae Alba and Fructus Chaenomelis, are combined into adjuvant herbal medicines. Lastly, if you suffer from the sthenic syndrome of the kidney, you need to invigorate your spleen which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to invigorate the spleen, which include taste and property invigoration according to the theory for properties and tastes of herbal medicines. Taste invigoration means to invigorate the spleen with sweet taste and property invigoration to invigorate the spleen with warm property. Therefore, it is important to use sweet herbal medicines for taste invigoration and warm ones for property invigoration. Both sweet and warm herbal medicines, Polyporus and Cortex Cinnamomi, were combined to invigorate the spleen and purge the kidney. In addition, Radix Glycyrrhizae are combined as dispatcher herbal medicine, harmonizing all the herbal medicines composing the formula. Conclusions : First, to cure the sthenic syndrome of the kidney, the methods of purging the kidney and the liver, and invigorating the spleen should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Pyeongshintang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.591-595
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• 2007

There are eight kinds of formulas for invigorating the liver to cure its asthenic syndrome based on the types of preparation formulas Began-tang, Boganhwan, Bogansan, Bogandan, Boganeum, Boganjoo, Boganjeon and Bogango. Another formula called Bocheonghwan is to invigorate the green colour of liver. There are 22 kinds of Bogan-tang, 12 kinds of Boganhwan, 25 kinds of Bogansan, one kind of Bogandan, one kind of Boganeum, one kind of Boganjoo, one kind of Boganjeon, one kind of Bogango, and two kinds of Bocheonghwan. Combination of herbal medicines, carried out in formulas for invigorating the liver, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Bogan-tang for curing the asthenic syndrome of liver through analyzing the component medicines and combination principles of Hyeongok's Bogan-tang, and furthermore, maximizing the clinical use of Began-tang. This study analyzed the component medicines and combination principles of Hyeongok's Bogan-tang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Began-tang is an odd prescription, composed of 7 kinds of ingredients No.1 Radix Angelicas Sinensis (2don;7.5g), No.2 Rhizoma Chuanxiong (1don;3.75g), No.3 Radii Polygoni Multiflori (1don), No.4 Fructus Lycii (1don), No.5 Cortex Cinnamomi (1don), No.6 Rhizoma Gastrodiae (1don), and No.7 Radix Glycyrrhizae (1don). There are three methods for curing the asthenic syndrome of liver according to the five elements doctrine invigorating the liver, invigorating the kidney and purging the lung. First, if you suffer from the asthenic syndrome of the liver, you need to invigorate your liver. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the pungent taste and the warm property invigorate the liver. In the case of taste invigoration, two herbal medicines with pungent taste, Radix Angelicas Sinensis and Rhizoma Chuanxiong, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herDal medicines with the warm property, Cortex Cinnamomi and Rhizoma Gastrodiae, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the liver, you need to invigorate your kidney which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the kidney, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the bitter taste and the cold property invigorate the kidney. Therefore, it is important to use bitter herbal medicines for taste invigoration and cold ones for property invigoration. Both Differ and cold herbal medicines, Radix Polygoni Multiflori and Fructus Lycii, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the liver, you need to purge your lung which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the lung, which include taste and property invigoration according to the theory for properties and tastes of herbal medicines. Taste invigoration means to purge the lung with pungent taste and property invigoration to purge the lung with warm property. Therefore, it is important to use pungent herbal medicines for taste invigoration and warm ones for property invigoration. Both pungent and warm herbal medicines, Radix Angelicas Sinensis and Rhizoma Chuanxiong, were combined to invigorate and purge the lung. In addition, Radix Glycyrrhizae are combined as dispatcher herbal medicine, harmonizing all the herbal medicines composing the formula. First, to cure the asthenic syndrome of the liver, the methods of invigorating the liver and the kidney, and purging the lung should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herDal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Bogan-tangon is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• Journal of Society of Preventive Korean Medicine
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• v.21 no.2
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• pp.1-13
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• 2017

Objectives : This paper serves to explore current trends of systems biology in Traditional Chinese Medicine (TCM) and examine how it may influence the Traditional Korean medicine. Methods : Literature review method was collectively used to classify Introduction to systems biology, diagnosis and syndrome classification of systems biology in TCM perspective, physiotherapy including acupuncture, herbs and formula functions, TCM systems biology, and directions of academic development. Results : The term 'Systems biology' is coined as a combination of systems science and biology. It is a field of study that tries to understand living organism by establishing a theory based on an ideal model that analyzes and predicts the desired output with understanding of interrelationships and dynamics between variables. Systems biology has an integrated and multi-dimensional nature that observes the interaction among the elements constructing the network. The current state of systems biology in TCM is categorized into 4 parts: diagnosis and syndrome, physical therapy, herbs and formulas and academic development of TCM systems biology and its technology. Diagnosis and syndrome field is focusing on developing TCM into personalized medicine by clarifying Kidney yin deficiency patterns and metabolic differences among five patterns of diabetes and analyzing plasma metabolism and biomarkers of coronary heart disease patients. In the field of physical therapy such as acupuncture and moxibustion, researchers discovered the effect of stimulating acupoint ST40 on gene expression and the effects of acupuncture on treating functional dyspepsia and acute ischemic stroke. Herbs and formulas were analyzed with TCM network pharmacology. The therapeutic mechanisms of Si Wu Tang and its series formulas are explained by identifying potential active substances, targets and mechanism of action, including metabolic pathways of amino acid and fatty acid. For the academic development of TCM systems biology and its technology, it is necessary to integrate massive database, integrate pharmacokinetics and pharmacodynamics, as well as systems biology. It is also essential to establish a platform to maximize herbal treatment through accumulation of research data and diseases-specific, or drug-specific network combined with clinical experiences, and identify functions and roles of molecules in herbs and conduct animal-based studies within TCM frame. So far, few literature reviews exist for systems biology in traditional Korean medicine and they merely re-examine known efficacies of simple substances, herbs and formulas. For the future, it is necessary to identify specific mechanisms of working agents and targets to maximize the effects of traditional medicine modalities. Conclusions : Systems biology is widely accepted and studied in TCM and already advanced into a field known as 'TCM systems biology', which calls for the study of incorporating TCM and systems biology. It is time for traditional Korean medicine to acknowledge the importance of systems biology and present scientific basis of traditional medicine and establish the principles of diagnosis, prevention and treatment of diseases. By doing so, traditional Korean medicine would be innovated and further developed into a personalized medicine.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.47-55
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• 1976

This study is conducted to find out potential evapotranspiration values computed by a reasonable formula which is well suited among the existing ones for Suweon area. Each formula based on the data from Suweon Agricultural Meteorological Station during 1964 to 1973. Five formulas which are Blanney-Criddle, Thornthwaite, Penman, Jensen-Haise and Truc have been applied for calculation of potential evapotanspiration. Results obtained are summarized as follows. 1. Potential evapotranspiration of Suweon area shows uni-modal distribution which maximum value occurs in summer and minimum value occurs in winter. Annual potential evapotranspiration computed by Blanney-Criddle formula is 1,377 mm and that computed by others ranges from 714mm to 896mm. 2. Potential evapotranspiration computed by Blanney-Criddle formula is higher value than that computed by others, and among the other formulas it's values show little differences. However, relationships between the former and the mean of four others is highly correlated. 3. In comparison with potential evapotranspiration computed by formulas and actual evapotranspiration for rice paddy which is already reported, value for crop coefficient may be 0.8 in local varities, 1.0 in Tongil varity on Blanney-Criddle formula, and 1.2 in local varities and 1.5 in Tongil varity on the mean of four other fomulas. 4. Five formulas may applied for calculation of potential evapotranspiration because of relatively good correlation among them. However Blanney-Criddle formula is one of recommendable ones, because it is easy to compute and requires less data in compare with other formulas.

• Steel and Composite Structures
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• v.21 no.1
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• pp.217-247
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• 2016

Five extended cylindrical reticulated shells are proposed by changing distribution rule of diagonal rods based on three fundamental types. Modeling programs for fundamental types and extended types of cylindrical reticulated shell are compiled by using the ANSYS Parametric Design Language (APDL). On this basis, conditional formulas are derived when the grid shape of cylindrical reticulated shells is equilateral triangle. Internal force analysis of cylindrical reticulated shells is carried out. The variation and distribution regularities of maximum displacement and stress are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of cylindrical reticulated shells and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization for three fundamental types and five extended types is calculated with the span of 30 m~80 m and rise-span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise-span ratio are analyzed with contrast to the results of shape optimization. The optimal combination of main design parameters for five extended cylindrical reticulated shells is investigated. The total steel consumption affected by distribution rule of diagonal rods is discussed. The results show that: (1) Parametric modeling method is simple, efficient and practical, which can quickly generate different types of cylindrical reticulated shells. (2) The mechanical properties of five extended cylindrical reticulated shells are better than their fundamental types. (3) The total steel consumption of cylindrical reticulated shells is optimized to be the least when rise-span ratio is 1/6. (4) The extended type of three-way grid cylindrical reticulated shell should be preferentially adopted in practical engineering. (5) The grid shape of reticulated shells should be designed to equilateral triangle as much as possible because of its reasonable stress and the lowest total steel consumption.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.789-798
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• 2009

In Sasang constitutional medicine, I have researched the process of visceral structure in the Eight Constitutionals under circulation of the five elements and the formation of primary source of illness. From this research, I could draw following conclusions through combination of the auxiliary psycho-formulas by applying the constitutional acupuncture therapy on the five elements diagnostic calculation. Since the arrangement for the five dimensions of organs in the eight constitutions has been formulated by circulation of the five elements in Sasang constitutions, if the five elements begin circulating count-clockwise from the reference point at the organs in Sasang constitutional medicine, the positive constitutional arrangement of organs is built up such as, the positive constitution of metal, earth, wood and water, while begin circulating clockwise, the negative constitutional arrangement of organs is formulated, such as the negative constitutions of metal, earth, wood and water. The source of illness results from imbalance of the organic force being generated by transfer of the five elements from compatibility to incompatibility when the five elements circulate. Hence, it has been acknowledged that if the source of illness comes from the strongest organ, it is the time when circulation of the five elements progresses from the second organ (the second strongest) in incompatibility, and if the source of illness comes from the weakest organ, it is the time when circulation of the five elements progresses from the third organ (the middle) in incompatibility. It is considered proper to diagnose meridians of the pericardium and the Triple Burners rather than to diagnose meridians of the heart and the small intestine which forms the visceral arrangement of the eight constitutions. For instance, the auxiliary psycho-formula obtains its prescription by attenuating the first organ (the strongest) while augmenting the fourth organ (the second weakest) when the axis of incompatibility in the five elements circulation crosses the second and the third organs, and it gets its prescription by attenuating the second organ(the second strongest) while augmenting the fifth organ(the weakest) when the axis of incompatibility in the five elements circulation crosses the third and the fourth organs. In addition, when medicating, the $4{\sim}5$ times of repeated performance can be assumed to represent the amount of an energy that each organ bears depending on the phase in the arrangement of the eight constitutional organs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1341-1345
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• 2007

There are four kinds of formulas for purging the liver to cure its sthenic syndrome based on the types of preparation formulas : Sagan-tang, Saganhwan, Saseem-san and Saganeum. Another formula called Sacheonghwan, Sacheong-tang and Sacheong-san is to purge the green colour of liver. There are 38 kinds of Sagan-tang, 2 kinds of Saganhwan, 29 kinds of Sagan-san, 5 kinds of Saganeum, 4 kinds of Sacheonghwan, 3 kinds of Sacheong-tang and 1 kind of Sacheong-san. Combination of herbal medicines, carried out in formulas for purging the liver, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Sagan-tang for curing the sthenic syndrome of liver through analyzing the component medicines and combination principles of Hyeongok's Sagan-tang, and furthermore, maximizing the clinical use of Sagan-tang. This study analyzed the component medicines and combination principles of Hyeongok's Sagan-tang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$, the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Sagan-tang is an odd prescription, composed of 7 kinds of ingredients : No.1 Radix Paeoniae (2don;7.5 g), No.2 Fructus Chaenomelis (1don;3.75 g), No.3 Radix Rehmanniae (1don), No.4 Folium Phyllostachydis Henonis (1don), No.5 Radix Bupleuri (1don), No.6 Radix Scutellariae (1don), and No.7 Radix Glycyrrhizae (1don). There are three methods for curing the sthenic syndrome of liver according to the five elements doctrine : purging the liver, purging the heart and invigorating the lung. In the case of taste purgation, two herbal medicines with sour taste, Radix Paeoniae and Fructus Chaenomelis, are combined into the principal and assistant herbal medicine, respectively. For property purgation, two herbal medicines with the cool property, Radix Bupleuri and Radix Scutellariae, are combined into adjuvant herbal medicines. Both sweet and cold herbal medicines, Radix Rehmanniae and Folium Phyllostachydis Henonis, are combined into adjuvant herbal medicines. Sour herbal medicines, Radix Paeoniae and Fructus Chaenomelis, were combined to invigorate the lung. Cool herbal medicines, Radix Bupleuri and Radix Scutellariae, were combined to invigorate the lung and to purge the liver. In addition, Radix Glycyrrhizae are combined as dispatcher herbal medicine, harmonizing all the herbal medicines composing the formula. First, to cure the sthenic syndrome of the liver, the methods of purging the liver and the heart, and invigorating the lung should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Sagan-tang is combined according to the above theories.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1139-1147
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• 2000

This paper describes that the size of inactive zone can be directly applied to design multiblade fan/scroll system. From the experimental studies using a five hole pitot tube and smoke test, it is found that the size of inactive zone has linear relations with the mean velocity of impeller inlet and cut-off angle gives a great influences to the fan efficiency. For the practical design, a function related with geometric parameters(i.e. inner radius, cord length, cut-off clearance and cut-off angle) of fan/scroll system is suggested. By using these formulas, the size and distribution of inactive zone can be predicted without the measurements through the full domain, it can be possible to use them to know the efficiency improvement for new model designed.