• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.3-49
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• 1990

This paper analyzes U.S. demand for imports from Asian NIEs and Japan, utilizing the Almost Ideal Demand System (AIDS) developed by Deaton and Muellbauer, with an emphasis on the effect of changes in the exchange rate. The empirical model assumes a two-stage budgeting process in which the first stage represents the allocation of total U.S. demand among three groups: the Asian NIEs and Japan, six Western developed countries, and the U.S. domestic non-tradables and import competing sector. The second stage represents the allocation of total U.S. imports from the Asian NIEs and Japan among them, by country. According to the AIDS model, the share equation for the Asia NIEs and Japan in U.S. nominal GNP is estimated as a single equation for the first stage. The share equations for those five countries in total U.S. imports are estimated as a system with the general demand restrictions of homogeneity, symmetry and adding-up, together with polynomially distributed lag restrictions. The negativity condition is also satisfied for all cases. The overall results of these complicated estimations, using quarterly data from the first quarter of 1972 to the fourth quarter of 1989, are quite promising in terms of the significance of individual estimators and other statistics. The conclusions drawn from the estimation results and the derived demand elasticities can be summarized as follows: First, the exports of each Asian NIE to the U.S. are competitive with (substitutes for) Japan's exports, while complementary to the exports of fellow NIEs, with the exception of the competitive relation between Hong Kong and Singapore. Second, the exports of each Asian NIE and of Japan to the U.S. are competitive with those of Western developed countries' to the U.S, while they are complementary to the U.S.' non-tradables and import-competing sector. Third, as far as both the first and second stages of budgeting are coneidered, the imports from each Asian NIE and Japan are luxuries in total U.S. consumption. However, when only the second budgeting stage is considered, the imports from Japan and Singapore are luxuries in U.S. imports from the NIEs and Japan, while those of Korea, Taiwan and Hong Kong are necessities. Fourth, the above results may be evidenced more concretely in their implied exchange rate effects. It appears that, in general, a change in the yen-dollar exchange rate will have at least as great an impact, on an NIE's share and volume of exports to the U.S. though in the opposite direction, as a change in the exchange rate of the NIE's own currency $vis-{\grave{a}}-vis$ the dollar. Asian NIEs, therefore, should counteract yen-dollar movements in order to stabilize their exports to the U.S.. More specifically, Korea should depreciate the value of the won relative to the dollar by approximately the same proportion as the depreciation rate of the yen $vis-{\grave{a}}-vis$ the dollar, in order to maintain the volume of Korean exports to the U.S.. In the worst case scenario, Korea should devalue the won by three times the maguitude of the yen's depreciation rate, in order to keep market share in the aforementioned five countries' total exports to the U.S.. Finally, this study provides additional information which may support empirical findings on the competitive relations among the Asian NIEs and Japan. The correlation matrices among the strutures of those five countries' exports to the U.S.. during the 1970s and 1980s were estimated, with the export structure constructed as the shares of each of the 29 industrial sectors' exports as defined by the 3 digit KSIC in total exports to the U.S. from each individual country. In general, the correlation between each of the four Asian NIEs and Japan, and that between Hong Kong and Singapore, are all far below .5, while the ones among the Asian NIEs themselves (except for the one between Hong Kong and Singapore) all greatly exceed .5. If there exists a tendency on the part of the U.S. to import goods in each specific sector from different countries in a relatively constant proportion, the export structures of those countries will probably exhibit a high correlation. To take this hypothesis to the extreme, if the U.S. maintained an absolutely fixed ratio between its imports from any two countries for each of the 29 sectors, the correlation between the export structures of these two countries would be perfect. Therefore, since any two goods purchased in a fixed proportion could be classified as close complements, a high correlation between export structures will imply a complementary relationship between them. Conversely, low correlation would imply a competitive relationship. According to this interpretation, the pattern formed by the correlation coefficients among the five countries' export structures to the U.S. are consistent with the empirical findings of the regression analysis.

• The Korean Journal of Physiology
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• v.5 no.1
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• pp.23-42
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• 1971

I. Chemical analysis A study was planned to see if administration of ginseng extract has any influence upon the adrenal, the hepatic, the splenic, and the pancreatic nucleic acid contents of rats, and to estimate the effect of ACTH administration as a substitute for stress reaction upon these nucleic acid contents of rats previously primed with ginseng. Ninety male rats$(body\;weight:\;150{\sim}200gm)$ were divided into the ginseng, the saline, and the normal control groups, which received for 5 days 0.5ml/100 gm body weight of ginseng extract solution (4 mg of ginseng alcohol extract in 1 ml of saline), same amount of saline, or no medication, respectively. On the 5th experimental day, each of the 3 groups was further divided into 2 subgroups yielding the ginseng, the ginseng-ACTIT, the saline, the saline-ACTH, the normal control, and the normal-ACTH subgroups. The ginseng, the saline, and the normal control subgroups were sacrificed 3 hours after the last medication, while the ginseng-ACTH, the saline·ACTH, and the normal-ACTH subgroups received ACTH(0.1 unit/subject) 1 hour after the last medication and were sacrificed after 1 more hour. The adrenal gland, the liver, the spleen and the pancreas of each rat were measured for RNA and DNA contents using the chemical method of Schmidt-Thannhauser-Schneider. Following results were obtained: 1. Adrenal RNA and DNA contents and RNA/DNA ratio were all significantly higher in the ginseng group compared with the values obtained from the normal control and the saline groups. Generally administration of ACTH reduced nucleic acid contents of the viscera examined. However, in the ginseng group the rate of decrease [(value of ginseng-ACTH subgroup-value of ginseng subgroup) x100/value of ginseng subgroup)] in adrenal RNA and DNA contents and in RNA/DNA ratio were more conspicuous than they were in the normal control and the saline groups. 2. Hepatic RNA and DNA contents and RNA/DNA ratio were all significantly less in the ginseng group than in the normal control and the saline groups. After ACTH, the rate of decrease in hepatic RNA, DNA, and RNA/DNA ratio of the ginseng· group was less conspicuous than those of the other 2 groups. 3. With regard to the splenic nucleic acid contents, the RNA and the RNA/DNA values of the ginseng group were higher than those of the normal control group but lower than those of the saline group, while the DNA value of the ginseng group was lower than that of the normal control group but higher than that of the saline group. Following administration of ACTH, the rate of decrease in RNA and DNA contents and in RNA/DNA ratio of the ginseng group was more conspicuous than that of the normal control group but less remarkable than that of the saline group. 4. Pancreatic RNA and DNA contents were notably lower in the ginseng group than in the normal control and the saline groups. However, the RNA/DNA ratio of the ginseng group was higher than that of the normal control and the saline groups.'After ACTH, the rate of decrease in pancreatic RNA and RNA/DNA ratio of the ginseng group was less than that of the normal. control group but more than that of the saline group, while the DNA content was actually increased in the ginseng group though it decreased in the normal control and the saline groups. Although the results are not clear enough for an accurate interpretation, they seem to indicate that ginseng exerts notable influence upon the RNA and DNA contents and the RNA/DNA ratio of the viscera stodied. On the whole the drug tends to increase the RNA and DNA contents and RNA/DNA ratio of the adrenal gland but seems to diminish the values of the other 3 viscera. In the early period following ACTH, ginseng facilitates the fall in RNA and DNA contents and RNA/DNA ratio of the adrenal gland, while it tends to reduce the fall in the values of the other viscera studied. II. Autoradiographic and histochemical analysis It was planned autoradiographically and histochemically to affirm and extend the results obtained in part I with regard to the chemically assessed change in the adrenal, the pancreatic, the hepatic and the splenic DNA and RNA contents under the influence of ginseng and ACTH. Fourty male mice (body weight: $18{\sim}20gm$) and 20 male rats were used. Each animal species was divided into the saline, the ginseng, the saline-ACTH, and the ginseng-ACTH groups according to the administered drugs. In the mice, the adrenal, the pancreatic, the splenic and the hepatic DNA-synthetic activity was assessed autoradiographically after administration of $^3H$-thymidine. In the rats, the RNA content of the above 4 organs was assessed histochemically after staining them with methylgreen pyronine. Following results were obtained: 1. Labeled cells were significantly more numerous in the adrenal cortex, the spleen and the liver of the ginseng group than in those of the saline group, although they were less numerous in the pancreas of the ginseng group than in the pancreas of the saline group. The adrenocortical, the pancreatic, the splenic and the hepatic tissues were stained with methylgreen pyronine more deeply in the ginseng group than in the saline group. 2. The adrenocortical, the pancreatic, the splenic and the hepatic tissues contained labeled cells less numerously in the saline-ACTH and the ginseng-ACTH group than in the saline and the ginseng groups. All these tissues were also stained with methylgreen pyronine less deeply in the saline-ACTH and the ginseng-ACTH groups than in the saline and the ginseng groups. 3. However, the adrenal cortex, the spleen, the pancreas, and the liver contained labeled cells more numerously in the ginseng-ACTH group than in the saline-ACTH group. the 4 tissues were stained with methylgreen pyronine more deeply in the ginseng-ACTH group than in the saline-ACTH group. It is inferred from the above results that though with exception, the ginseng mostly facilitates cellular synthesis of nucleic acids and mitigates reduction in nucleic acid content of tissues after administration of ACTH.

• Journal of Korean Society of Forest Science
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• v.52 no.1
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• pp.58-71
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• 1981

Thecodiplosis japonesis is sweeping the Pinus densiflora forests from south-west to north-east direction, destroying almost all the aged large trees as well as even the young ones. The front line of infestation is moving slowly but ceaselessly norhwards as a long bottle front. Estimation is that more than 40 percent of the area of P. densiflora forest has been damaged already, however some individuals could escapes from the damage and contribute to restore the site to the previous vegetation composition. When the stands were attacked by this insect, the drastic openings of the upper story of tree canopy formed by exclusively P. densiflora are usually resulted and some environmental factors such as light, temperature, litter accumulation, soil moisture and offers were naturally modified. With these changes after insect invasion, as the time passes, phytosociologic changes of the vegetation are gradually proceeding. If we select the forest according to four categories concerning the history of the insect outbreak, namely, non-attacked (healthy forest), recently damaged (the outbreak occured about 1-2 years ago), severely damaged (occured 5-6 years ago), damage prolonged (occured 10 years ago) and restored (occured about 20 years ago), any directional changes of vegetation composition could be traced these in line with four progressive stages. To elucidate these changes, three survey districts; (1) "Gongju" where the damage was severe and it was outbroken in 1977, (2) "Buyeo" where damage prolonged and (3) "Gochang" as restored, were set, (See Tab. 1). All these were located in the south temperate forest zone which was delimited mainly due to the temporature factor and generally accepted without any opposition at present. In view of temperature, the amount and distribution of precipitation and various soil factor, the overall homogeneity of environmental conditions between survey districts might be accepted. However this did not mean that small changes of edaphic and topographic conditions and microclimates can induce any alteration of vegetation patterns. Again four survey plots were set in each district and inter plot distance was 3 to 4 km. And again four subplots were set within a survey plot. The size of a subplot was $10m{\times}10m$ for woody vegetation and $5m{\times}5m$ for ground cover vegetation which was less than 2 m high. The nested quadrat method was adopted. In sampling survey plots, the followings were taken into account: (1) Natural growth having more than 80 percent of crown density of upper canopy and more than 5 hectares of area. (2) Was not affected by both natural and artificial disturbances such as fire and thinning operation for the past three decades. (3) Lower than 500 m of altitude (4) Less than 20 degrees of slope, and (5) Northerly sited aspect. An intensive vegetation survey was undertaken during the summer of 1980. The vegetation was devided into 3 categories for sampling; the upper layer (dominated mainly by the pine trees), the middle layer composed by oak species and other broad-leaved trees as well as the pine, and the ground layer or the lower layer (shrubby form of woody plants). In this study our survey was concentrated on woody species only. For the vegetation analysis, calculated were values of intensity, frequency, covers, relative importance, species diversity, dominance and similarity and dissimilasity index when importance values were calculated, different relative weights as score were arbitrarily given to each layer, i.e., 3 points for the upper layer, 2 for the middle layer and 1 for the ground layer. Then the formula becomes as follows; $$R.I.V.=\frac{3(IV\;upper\;L.)+2(IV.\;middle\;L.)+1(IV.\;ground\;L.)}{6}$$ The values of Similarity Index were calculated on the basis of the Relative Importance Value of trees (sum of relative density, frequency and cover). The formula used is; $$S.I.=\frac{2C}{S_1+S_2}{\times}100=\frac{2C}{100+100}{\times}100=C(%)$$ Where: C = The sum of the lower of the two quantitative values for species shared by the two communities. $S_1$ = The sum of all values for the first community. $S_2$ = The sum of all values for the second community. In Tab. 3, the species composition of each plot by layer and by district is presented. Without exception, the species formed the upper layer of stands was Pinus densiflora. As seen from the table, the relative cover (%), density (number of tree per $500m^2$), the range of height and diameter at brest height and cone bearing tendency were given. For the middle layer, Quercus spp. (Q. aliena, serrata, mongolica, accutissina and variabilis) and Pinus densiflora were dominating ones. Genus Rhodedendron and Lespedeza were abundant in ground vegetation, but some oaks were involved also. (1) Gongju district The total of woody species appeared in this district was 26 and relative importance value of Pinus densiflora for the upper layer was 79.1%, but in the middle layer, the R.I.V. for Quercus acctissima, Pinus densiflora, and Quercus aliena, were 22.8%, 18.7% and 10.0%, respectively, and in ground vegetation Q. mongolica 17.0%, Q. serrata 16.8% Corylus heterophylla 11.8%, and Q. dentata 11.3% in order. (2) Buyeo district. The number of species enumerated in this district was 36 and the R.I.V. of Pinus densiflora for the uppper layer was 100%. In the middle layer, the R.I.V. of Q. variabilis and Q. serrata were 8.6% and 8.5% respectively. In the ground vegetative 24 species were counted which had no more than 5% of R.I.V. The mean R.I.V. of P.densiflora ( totaling three layers ) and averaging four plots was 57.7% in contrast to 46.9% for Gongju district. (3) Gochang-district The total number of woody species was 23 and the mean R.I.V. of Pinus densiflora was 66.0% showing greater value than those for two former districts. The next high value was 6.5% for Q. serrata. As the time passes since insect outbreak, the mean R.I.V. of P. densiflora increased as the following order, 46.9%, 57.7% and 66%. This implies that P. densiflora was getting back to its original dominat state again. The pooled importance of Genus Quercus was decreasing with the increase of that for Pinus densiflora. This trend was contradict to the facts which were surveyed at Kyonggi-do area (the central temperate forest zone) reported previously (Yim et al, 1980). Among Genus Quercus, Quercus acutissina, warm-loving species, was more abundant in the southern temperature zone to which the present research is concerned than the central temperate zone. But vice-versa was true with Q. mongolica, a cold-loving one. The species which are not common between the present survey and the previous report are Corpinus cordata, Beltala davurica, Wisturia floribunda, Weigela subsessilis, Gleditsia japonica var. koraiensis, Acer pseudosieboldianum, Euonymus japonica var. macrophylla, Ribes mandshuricum, Pyrus calleryana var. faruiei, Tilia amurensis and Pyrus pyrifolia. In Figure 4 and Table 5, Maximum species diversity (maximum H'), Species diversity (H') and Eveness (J') were presented. The Similarity indices between districts were shown in Tab. 5. Seeing Fig. 6, showing two-dimensional ordination of polts on the basis of X and Y coordinates, Ai plots aggregate at the left site, Bi plots at lower site, and Ci plots at upper-right site. The increasing and decreasing patterns as to Relative Density and Relative Importance Value by genus or species were given in Fig. 7. Some of the patterns presented here are not consistent with the previously reported ones (Yim, et al, 1980). The present authors would like to attribute this fact that two distinct types of the insect attack, one is the short war type occuring in the south temperate forest zone, which means that insect attack went for a few years only, the other one is a long-drawn was type observed at the temperate forest zone in which the insect damage went on continuously for several years. These different behaviours of infestation might have resulted the different ways of vegetational change. Analysing the similarity indices between districts, the very convincing results come out that the value of dissimilarity index between A and B was 30%, 27% between B and C and 35% between A and C (Table 6). The range of similarity index was obtained from the calculation of every possible combinations of plots between two districts. Longer time isolation between communities has brought the higher value of dissimilarity index. The main components of ground vegetation, 10 to 20 years after insect outbreak, become to be consisted of mainly Genus Lespedeza and Rhododendron. Genus Quercus which relate to the top dorminant state for a while after insect attack was giving its place to Pinus densiflora. It was implied that, provided that the soil fertility, soil moisture and soil depth were good enough, Genus Quercuss had never been so easily taken ever by the resistant speeies like Pinus densiflora which forms the edaphic climax at vast areas of forest land. Usually they refer Quercus to the representative component of the undisturbed natural forest in the central part of this country.