• Journal of Intelligence and Information Systems
• /
• v.26 no.4
• /
• pp.111-126
• /
• 2020

Most industries have recently become aware of the importance of customer lifetime value as they are exposed to a competitive environment. As a result, preventing customers from churn is becoming a more important business issue than securing new customers. This is because maintaining churn customers is far more economical than securing new customers, and in fact, the acquisition cost of new customers is known to be five to six times higher than the maintenance cost of churn customers. Also, Companies that effectively prevent customer churn and improve customer retention rates are known to have a positive effect on not only increasing the company's profitability but also improving its brand image by improving customer satisfaction. Predicting customer churn, which had been conducted as a sub-research area for CRM, has recently become more important as a big data-based performance marketing theme due to the development of business machine learning technology. Until now, research on customer churn prediction has been carried out actively in such sectors as the mobile telecommunication industry, the financial industry, the distribution industry, and the game industry, which are highly competitive and urgent to manage churn. In addition, These churn prediction studies were focused on improving the performance of the churn prediction model itself, such as simply comparing the performance of various models, exploring features that are effective in forecasting departures, or developing new ensemble techniques, and were limited in terms of practical utilization because most studies considered the entire customer group as a group and developed a predictive model. As such, the main purpose of the existing related research was to improve the performance of the predictive model itself, and there was a relatively lack of research to improve the overall customer churn prediction process. In fact, customers in the business have different behavior characteristics due to heterogeneous transaction patterns, and the resulting churn rate is different, so it is unreasonable to assume the entire customer as a single customer group. Therefore, it is desirable to segment customers according to customer classification criteria, such as loyalty, and to operate an appropriate churn prediction model individually, in order to carry out effective customer churn predictions in heterogeneous industries. Of course, in some studies, there are studies in which customers are subdivided using clustering techniques and applied a churn prediction model for individual customer groups. Although this process of predicting churn can produce better predictions than a single predict model for the entire customer population, there is still room for improvement in that clustering is a mechanical, exploratory grouping technique that calculates distances based on inputs and does not reflect the strategic intent of an entity such as loyalties. This study proposes a segment-based customer departure prediction process (CCP/2DL: Customer Churn Prediction based on Two-Dimensional Loyalty segmentation) based on two-dimensional customer loyalty, assuming that successful customer churn management can be better done through improvements in the overall process than through the performance of the model itself. CCP/2DL is a series of churn prediction processes that segment two-way, quantitative and qualitative loyalty-based customer, conduct secondary grouping of customer segments according to churn patterns, and then independently apply heterogeneous churn prediction models for each churn pattern group. Performance comparisons were performed with the most commonly applied the General churn prediction process and the Clustering-based churn prediction process to assess the relative excellence of the proposed churn prediction process. The General churn prediction process used in this study refers to the process of predicting a single group of customers simply intended to be predicted as a machine learning model, using the most commonly used churn predicting method. And the Clustering-based churn prediction process is a method of first using clustering techniques to segment customers and implement a churn prediction model for each individual group. In cooperation with a global NGO, the proposed CCP/2DL performance showed better performance than other methodologies for predicting churn. This churn prediction process is not only effective in predicting churn, but can also be a strategic basis for obtaining a variety of customer observations and carrying out other related performance marketing activities.

• The Journal of Korean Society for Radiation Therapy
• /
• v.32
• /
• pp.93-109
• /
• 2020

Purpose: The radiochromic film (Gafchromic EBT3, Ashland Advanced Materials, USA) and 3-dimensional analysis system dosimetry checkTM (DC, MathResolutions, USA) were evaluated for patient-specific quality assurance (QA) of helical tomotherapy. Materials and Methods: Depending on the tumors' positions, three types of targets, which are the abdominal tumor (130.6㎤), retroperitoneal tumor (849.0㎤), and the whole abdominal metastasis tumor (3131.0㎤) applied to the humanoid phantom (Anderson Rando Phantom, USA). We established a total of 12 comparative treatment plans by the four geometric conditions of the beam irradiation, which are the different field widths (FW) of 2.5-cm, 5.0-cm, and pitches of 0.287, 0.43. Ionization measurements (1D) with EBT3 by inserting the cheese phantom (2D) were compared to DC measurements of the 3D dose reconstruction on CT images from beam fluence log information. For the clinical feasibility evaluation of the DC, dose reconstruction has been performed using the same cheese phantom with the EBT3 method. Recalculated dose distributions revealed the dose error information during the actual irradiation on the same CT images quantitatively compared to the treatment plan. The Thread effect, which might appear in the Helical Tomotherapy, was analyzed by ripple amplitude (%). We also performed gamma index analysis (DD: 3mm/ DTA: 3%, pass threshold limit: 95%) for pattern check of the dose distribution. Results: Ripple amplitude measurement resulted in the highest average of 23.1% in the peritoneum tumor. In the radiochromic film analysis, the absolute dose was on average 0.9±0.4%, and gamma index analysis was on average 96.4±2.2% (Passing rate: >95%), which could be limited to the large target sizes such as the whole abdominal metastasis tumor. In the DC analysis with the humanoid phantom for FW of 5.0-cm, the three regions' average was 91.8±6.4% in the 2D and 3D plan. The three planes (axial, coronal, and sagittal) and dose profile could be analyzed with the entire peritoneum tumor and the whole abdominal metastasis target, with planned dose distributions. The dose errors based on the dose-volume histogram in the DC evaluations increased depending on FW and pitch. Conclusion: The DC method could implement a dose error analysis on the 3D patient image data by the measured beam fluence log information only without any dosimetry tools for patient-specific quality assurance. Also, there may be no limit to apply for the tumor location and size; therefore, the DC could be useful in patient-specific QAl during the treatment of Helical Tomotherapy of large and irregular tumors.

• Journal of Intelligence and Information Systems
• /
• v.27 no.1
• /
• pp.83-102
• /
• 2021

The government recently announced various policies for developing big-data and artificial intelligence fields to provide a great opportunity to the public with respect to disclosure of high-quality data within public institutions. KSURE(Korea Trade Insurance Corporation) is a major public institution for financial policy in Korea, and thus the company is strongly committed to backing export companies with various systems. Nevertheless, there are still fewer cases of realized business model based on big-data analyses. In this situation, this paper aims to develop a new business model which can be applied to an ex-ante prediction for the likelihood of the insurance accident of credit guarantee. We utilize internal data from KSURE which supports export companies in Korea and apply machine learning models. Then, we conduct performance comparison among the predictive models including Logistic Regression, Random Forest, XGBoost, LightGBM, and DNN(Deep Neural Network). For decades, many researchers have tried to find better models which can help to predict bankruptcy since the ex-ante prediction is crucial for corporate managers, investors, creditors, and other stakeholders. The development of the prediction for financial distress or bankruptcy was originated from Smith(1930), Fitzpatrick(1932), or Merwin(1942). One of the most famous models is the Altman's Z-score model(Altman, 1968) which was based on the multiple discriminant analysis. This model is widely used in both research and practice by this time. The author suggests the score model that utilizes five key financial ratios to predict the probability of bankruptcy in the next two years. Ohlson(1980) introduces logit model to complement some limitations of previous models. Furthermore, Elmer and Borowski(1988) develop and examine a rule-based, automated system which conducts the financial analysis of savings and loans. Since the 1980s, researchers in Korea have started to examine analyses on the prediction of financial distress or bankruptcy. Kim(1987) analyzes financial ratios and develops the prediction model. Also, Han et al.(1995, 1996, 1997, 2003, 2005, 2006) construct the prediction model using various techniques including artificial neural network. Yang(1996) introduces multiple discriminant analysis and logit model. Besides, Kim and Kim(2001) utilize artificial neural network techniques for ex-ante prediction of insolvent enterprises. After that, many scholars have been trying to predict financial distress or bankruptcy more precisely based on diverse models such as Random Forest or SVM. One major distinction of our research from the previous research is that we focus on examining the predicted probability of default for each sample case, not only on investigating the classification accuracy of each model for the entire sample. Most predictive models in this paper show that the level of the accuracy of classification is about 70% based on the entire sample. To be specific, LightGBM model shows the highest accuracy of 71.1% and Logit model indicates the lowest accuracy of 69%. However, we confirm that there are open to multiple interpretations. In the context of the business, we have to put more emphasis on efforts to minimize type 2 error which causes more harmful operating losses for the guaranty company. Thus, we also compare the classification accuracy by splitting predicted probability of the default into ten equal intervals. When we examine the classification accuracy for each interval, Logit model has the highest accuracy of 100% for 0~10% of the predicted probability of the default, however, Logit model has a relatively lower accuracy of 61.5% for 90~100% of the predicted probability of the default. On the other hand, Random Forest, XGBoost, LightGBM, and DNN indicate more desirable results since they indicate a higher level of accuracy for both 0~10% and 90~100% of the predicted probability of the default but have a lower level of accuracy around 50% of the predicted probability of the default. When it comes to the distribution of samples for each predicted probability of the default, both LightGBM and XGBoost models have a relatively large number of samples for both 0~10% and 90~100% of the predicted probability of the default. Although Random Forest model has an advantage with regard to the perspective of classification accuracy with small number of cases, LightGBM or XGBoost could become a more desirable model since they classify large number of cases into the two extreme intervals of the predicted probability of the default, even allowing for their relatively low classification accuracy. Considering the importance of type 2 error and total prediction accuracy, XGBoost and DNN show superior performance. Next, Random Forest and LightGBM show good results, but logistic regression shows the worst performance. However, each predictive model has a comparative advantage in terms of various evaluation standards. For instance, Random Forest model shows almost 100% accuracy for samples which are expected to have a high level of the probability of default. Collectively, we can construct more comprehensive ensemble models which contain multiple classification machine learning models and conduct majority voting for maximizing its overall performance.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.1
• /
• pp.1-8
• /
• 2022

In order to manufacture feed suitable for consumer use and provide feed value information, we analyzed the feed components of the four main forage rice varieties by plant parts harvested 30 days after heading. The contents of the six feed ingredients were significantly different (p<0.05) among harvested parts. In the panicle, the crude protein (CP) (6.97%) and lignin (3.11%) were the highest, while the crude ash (CA) and neutral detergent fiber (NDF) contents were significantly lower, resulting in a total digestible nutrient (TDN) content of 77.29%, which is higher than that of the stem (64.82%) and leaf blade and sheath (LBS) (63.57%) (p<0.05). In contrast, the content of crude fat (CF) did not differ significantly among parts (p<0.05). In panicles from 'Jonong', 'Nokyang' and 'Yeongwoo', the TDN content of each cultivar was 78.48-79.07%, with no significant difference among the varieties. In 'Mogwoo' (Mw), the CP content was 8.70%, which was much higher than that of other varieties (p<0.05). In particular, the Mw TDN content was slightly lower in the panicle (72.95%) but higher in the stem (75.37%) and LBS (66.49%) than in the other varieties. The CA, NDF, acid detergent fiber (ADF), and lignin contents were also very low compared to other varieties; therefore, the feed value of the stem and LBS was excellent. In addition, the total dry matter weight (DMW) was 123 g per hill, which was much higher than 82-105 g per hill for other varieties. The distribution of DMW by part was LBS (56.9 g), stem (36.8 g), and panicle (29.3 g), and because the parts, except the panicles, were much higher than the 43-57% of other varieties (grain straw ratio: 76%), rice straw is advantageous in terms of quantity and feed value when used as forage on farms. The relative feed value (RFV) of the four cultivars ranged from 86.79-403.74 across all parts, and hay of grade 3 or higher with an RFV of 100 or more increased with delayed heading in both stems and LBS. This is due to the accumulation of starch into grains during ripening, which supports the observation that the RFV of the early flowering 'Jonong' and 'Nokyang' panicles increased.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.1
• /
• pp.15-26
• /
• 1994

To understand the relative contribution of varietal and environmental variation on various grain quality components in rice, grain appearance, milling recovery, several physicochemical properties of rice grain and texture or palatability of cooked rice for milled rice materials of seven cultivars(five japonica & two Tongil-type), produced at six locations of the middle and southern plain area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal variations were detected in all grain quality components of the rice materials and marked locational variations with about 14-54% portion of total variation were recognized in grain appearance, milling recovery, alkali digestibility, protein content, K /Mg ratio, gelatinization temperature, breakdown and setback viscosities. Variations of variety x location interaction were especially large in overall palatability score of cooked rice and consistency or set- back viscosities of amylograph. Tongil-type cultivars showed poor marketing quality, lower milling recovery, slightly lower alkali digestibility and amylose content, a little higher protein content and K /Mg ratio, relatively higher peak, breakdown and consistency viscosities, significantly lower setback viscosity, and more undesirable palatability of cooked rice compared with japonica rices. The japonica rice varieties possessing good palatability of cooked rice were slightly low in protein content and a little high in K /Mg ratio and stickiness /hardness ratio of cooked rice. Rice 1000-kernel weight was significantly heavier in rice materials produced in Iri lowland compared with other locations. Milling recovery from rough to brown rice and ripening quality were lowest in Milyang late-planted rice while highest in Iri lowland and Gyehwa reclaimed-land rice. Amylose content of milled rice was about 1% lower in Gyehwa rice compared with other locations. Protein content of polished rice was about 1% lower in rice materials of middle plain area than those of southern plain regions. K/Mg ratio of milled rice was lowest in Iri rice while highest in Milyang rice. Alkali digestibility was highest in Milyang rice while lowest in Honam plain rice, but the temperature of gelatinization initiation of rice flour in amylograph was lowest in Suwon and Iri rices while highest in Milyang rice. Breakdown viscosity was lowest in Milyang rice and next lower in Ichon lowland rice while highest in Gyehwa and Iri rices, and setback viscosity was the contrary tendency. The stickiness/hardness ratio of cooked rice was slightly lower in southern-plain rices than in middle-plain ones, and the palatability of cooked rice was best in Namyang reclaimed-land rice and next better with the order of Suwon$\geq$Iri$\geq$Ichon$\geq$Gyehwa$\geq$Milyang rices. The rice materials can be classified genotypically into two ecotypes of japonica and Tongil-type rice groups, and environmentally into three regions of Milyang, middle and Honam lowland by the distribution on the plane of 1st and 2nd principal components contracted from eleven grain quality properties closely associated with palatability of cooked rice by principal component analysis.

• The Journal of Korean Society for Radiation Therapy
• /
• v.34
• /
• pp.21-30
• /
• 2022

Purpose: The purpose of this study is to evaluate the effectiveness of oral positioning stent, the BinkieRT^TM in radiation treatment for head and neck cancer patients in terms of tongue positions reproducibility, tongue doses and material properties. Materials and Methods: 24 cases using BinkieRT^TM during radiation treatments were enrolled. The tongue was contoured on planning CT and CBCT images taken every 3 days during treatment, and then the DSC and center of tongue shift values were analyzed to evaluate the reproducibility of the tongue. The tongue dose was compared in terms of dose distribution when using BinkieRT^TM and different type of oral stents (mouthpiece, paraffin wax). Randomly selected respective 10 patients were measured tongue doses of initial treatment plan for nasal cavity and unilateral parotid cancer. Finally, In terms of material evaluation, HU and relative electron density were identified in RTPS. Results: As a result of DSC analysis, it was 0.8 ± 0.07, skewness -0.8, kurtosis 0.61, and 95% CI was 0.79~0.82. To analyze the deviation of the central tongue shift during the treatment period, a 95% confidence interval for shift in the LR, SI, and AP directions were indicated, and a one-sample t-test for 0, which is an ideal value in the deviation(n=144). As a result of the t-test, the mean and SD in the LR and SI directions were 0.01 ± 0.14 cm (p→.05), 0.03 ± 0.25 cm (p→.05), and -0.08 ± 0.25 cm (p ←.05) in the AP direction. In the case of unilateral parotid cancer patients, the Dmean to the tongue of patients using BinkieRT^TM was 16.92% ± 3.58% compared to the prescribed dose, and 23.99% ± 10.86% of patients with Paraffin Wax, indicating that the tongue dose was relatively lower when using BinkieRT^TM (p←.05). On the other hand, among nasal cavity cancer patients, the Dmean of tongue dose for patients who used BinkieRT^TM was 4.4% ± 5.6%, and for those who used mouthpiece, 5.9% ± 6.8%, but it was not statistically significant (p→.05). The relative electron density of Paraffin Wax, BinkieRT^TM and Putty is 0.94, 0.99, 1.26 and the mass density is 0.95, 0.99 and 1.32 (g/cc), Transmission Factor is 0.99, 0.98, 0.96 respectively. Conclusion: The result of the tongue DSC analysis over the treatment period was about 0.8 and Deviation of the center of tongue shifts were within 0.2 cm, the reproducibility was more likely excellent. In the case of unilateral head and neck cancer patients, it was found that the use of BinkieRT^TM rather than Paraffin Wax or Putty can reduce the unnecessary dose irradiated to the tongue. This study might be useful to understand of BinkieRT^TM's properties and advantages. And also it could be another considered option as oral stent to keep the reproducibility of tongue and reducing dose during head and neck radiation treatments.

• The Korean Journal of Zoology
• /
• v.20 no.1
• /
• pp.29-40
• /
• 1977

The authors examined fresh-water gammarid materials which were collected from streams in 20 localities of South Korea during the period from 1965 to 1977. As the results of the observation, the authors have concluded as follows: 1. These fresh-water gammarids belong to Gammarus pulex-group and are distributed widely in mountain-streams of mainland and surrounding islands of South Korea. 2. The present specimens are different from the subspecies, G. pulex koreanus Ueno, 1940 which was described originally from North Korea. In the latter, the pulmose setae of third uropod are limited only to the outer margin of both rami. The peduncle and flagellum of second antenna are fringed with a few short setae and the flagellum is provided with calceoli. In the former, both margins of inner ramus and outer margin of outer ramus of third uropod are fringed with long pulmose setae. The peduncle and flagellum of second antenna have abundant relatively long setase and the flagellum is not provided with calceoli. 3. The present specimens are different from the subspecies, G. pulex sobaegensis Ueno, 1966 which was described originally from South Korea. The latter dwells in cave, while the former dwells in mountain-stream. In the former, the arrangements of pulmose setae of third uropod and the setation of second antenna are similar to those of the latter. But they are quite different from each other in several characters such as shape of upper lip, shape of fifth article of second gnathopod and numbers of incisions on front distal margins of coxal plates 1-3. The former has spines on surface of coxal plates 1-3, but the latter has not. In females, the former has four pairs of marsupial plates, while the latter has three pairs. 4. The present materials show local variations. Therefore, they could be divided into 3 local groups. The first group (specimens from Mt. Odae and Mt. Sogeumgang) has pulmose setae on the both margins of both rami of third uropod and second article of outer ramus is relatively long. In general, this group has setae sparsely on the both rami and especially a few setae on the outer margin of outer ramus. The second group, which are widely distributed in South Korea, has pulmose setae on the both margins of inner ramus and on the outer margin of outer ramus of third uropod. In the third group (specimens from Mt. Soyo), the pulmose setation of third uropod is similar to that of the first group, but the second article of outer ramus is very small.

• Journal of Venture Innovation
• /
• v.7 no.2
• /
• pp.77-99
• /
• 2024

Small and medium-sized venture companies and small business owners play an important role in the Korean economy. According to the Ministry of SMEs and Startups' statistics survey in 2019, the proportion of all employees of small and medium-sized venture companies in Korea was 89.8%, which is overwhelmingly higher than that of Japan's 77.8% and Taiwan's 76.6%, so job creation for small and medium-sized venture companies in Korea is absolute. Compared to large companies, it is known that it is difficult for small and medium-sized venture companies in Korea to secure a competitive advantage due to low cost competitiveness, difficulties in R&D/marketing due to lack of capital, difficulties in securing networks, and lack of management know-how. Many scholars, including Kerr and Schumpeter, have studied entrepreneurship since the mid-1950s. Recently, research has been conducted in various fields such as business administration, psychology, and economics. However, research on the personal characteristics of CEOs of small and medium-sized venture companies such as entrepreneurial passion and corporate reputation, which is the overall image of companies, is still insufficient, and comparisons of effects between variables between groups (by industry, by pressure, etc.) have not yet been presented. Entrepreneurial passion plays an important role in promoting new business creation, job creation, and economic growth. Therefore, entrepreneurial Cultivating and promoting passion will also contribute to socioeconomic development. These are government policies, educational programs, and social awareness It can be achieved through improvement, etc., and is especially important in the current market conditions where innovation and growth are important. In conclusion Entrepreneurial passion is an important factor that has a positive effect on all individuals, businesses, and society. Therefore, research on entrepreneurial passion is It is an essential task to maximize these positive effects. In this study, in order to overcome the limitations of existing studies, entrepreneurs' Whether entrepreneurial passion, which is a personal characteristic, affects competitive advantage, absorption capacity and product and process innovation capabilities are Whether there is a mediating effect between entrepreneurial passion and competitive advantage. Finally, in the relationship between entrepreneurial passion and absorption capacity. The corporate reputation verifies whether it has a moderating effect, etc., and compares the influencing factors between variables by industry and pressure. It is intended to be verified empirically. In this study, 2023 conducted by the Small and Medium Business Distribution Center under the Ministry of SMEs and Startups for 312 CEOs of small and medium-sized venture companies and small business owners who participated in the online market support project for small and medium-sized venture companies and small business owners, December 2023 Survey and analysis were conducted from 1st to 20th, and the analysis used Smart PLS 4.0 to determine the impact on the relationship between variables. It was empirically verified. As a result of the study, it was found that entrepreneurial passion had a positive effect on absorption capacity, and the product was found And it was found to have a positive effect on process innovation capability and competitive advantage. In addition, the higher the corporate reputation, the more entrepreneurial it is. It was confirmed that passion had a greater effect on absorption capacity.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.42 no.1
• /
• pp.1-13
• /
• 2024

This study requires a strict distinction between the sculptures we call 'Jangseung' because their origins, history, or functions are different from each other. Therefore, a theoretical consideration was made through the origin and history of Jangseung. Currently, Jangseung is widely distributed throughout the country, but the Honam region shows the largest distribution, and 73 out of 167 locations nationwide remain in the Chungcheongnam-do region. Among these, there are 54 stone jangseungs in Jeollanam-do, 37 in Jeollabuk-do, and 19 in Jeollabuk-do. In particular, the original shape of the stone jangseungs in the Honam region is well preserved, and as a center of the agricultural economy, the jangseung culture is active in this region. It was popular, and many stone jangseungs were built in the Daejeon area amid social changes in the late Joseon Dynasty. However, in the South Chungcheong region, there is not much culture about stone jangseungs, but there is a village meaning and consciousness that stone jangseungs have, but it is true that research on stone jangseungs is insufficient in various aspects. Among them, the form of the stone jangseung built between the 17th and 19th centuries is a sculpture that contrasts with the wooden pillar-type jangseung that is common in the central region, and shows the simple mentality of the people of the Daejeon region without any embellishment. Through Jangseung, we were able to discover the unconscious and potential creativity of national aesthetic consciousness. Therefore, the purpose is to trace the change process of the stone jangseung in the Daejeon area, investigate the functional aspects of this structure, and based on this, examine the various current status and locational characteristics of the so-called stone jangseung. In addition, the wooden figures and stone statues that are now commonly known as Jangseung were each erected in different times and for different reasons. Centering around Daejeon, the study attempted to research and identify representative stone monuments or 'stone jangseungs' that appear as stone statues, and even suggest their form through locational characteristics and suggestions. As a result, traditional jangseungs have changed in various forms as times change, reaching their present form, and the religious elements of modern jangseungs made and erected today are weakened or disappeared, and are used as symbolic symbols or sculptures of tradition. Although it has lost its traditional function as an object of village faith, it functions as a milestone or sign at the entrance to a village or event site, or as an exhibition in special places. It was found that the modern jangseung is a representative symbol of Korean traditional culture and is being re-created as an artistic sculpture that expresses common, simple, natural beauty and humor. Therefore, through this study, based on more specific and systematic investigation and research on the jangseung, it was materialized into a more developed form considering its utilization plan to prevent miscellaneous spirits from entering the village through the currently existing stone jangseung and to improve the spatial space accordingly. It is believed that what is located at the entrance can greatly convey its meaning. Therefore, it is judged necessary to maintain the strong characteristics of folk religion without the sophistication of foreign religions for various deities.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.17
• /
• pp.1-44
• /
• 1974

These studies were made at Suwon in 1972 and at Suwon, Iri, and Kwangju in 1973 to investigate grain filling process and variation of grain quality of NB 68513 and Caprock as hard red winter wheat, Suke ＃169 as soft red winter wheat variety and Yungkwang as semi-hard winter variety, grown under-three different fertilizer levels and seeding dates. Other experiments were conducted to find the effects of temperature, humidity and light intensity on the grain filling process and grain quality of Yungkwang and NB 68513 wheat varieties. These, experiments were conducted at Suwon in 1973 and 1974. 1. Grain filling process of wheat cultivars: 1) The frequency distribution of a grain weight shows that wider distribution of grain weight was associated with large grain groups rather than small grain group. In the large grain groups, the frequency was mostly concentrated near mean value, while the frequency was dispersed over the values in the small grain group. 2) The grain weight was more affected by the grain thickness and width than by grain length. 3) The grain weight during the ripening period was rapidly increased from 14 days after flowering to 35 days in Yungkwang and from 14 days after flowering to 28 days in NB 68513. The large grain group, Yungkwang was rather slowly increased and took a longer period in increase of endosperm ratio of grain than the small grain group, NB 68513. 4) In general, the 1, 000 grain weight was reduced under high temperature, low humidity, while it was increased under low temperature and high humidity condition, and under high temperature and humidity condition. The effect of shading on grain weight was greater in high temperature than in low temperature condition and no definite tendency was found in high humidity condition. 5) The effects of temperature, humidity and shading on 1, 000 grain weight were greater in large-grain group, Yungkwang than in small grain group, NB 68513. Highly significant positive correlation was found between 1, 000 grain weight and days to ripening. 6) The 1, 000 grain weight and test weight were increased more or less as the fertilizer levels applied were increased. However, the rate of increasing 1, 000 grain weight was low when fertilizer levels were increased from standard to double. The 1, 000 grain weight was high when planted early. Such tendency was greater in Suwon than in Kwangju or Iri area. 2. Milling quality: 7) The milling rate in a same group of varieties was higher under the condition of low temperature, high humidity and early maturing culture which were responsible for increasing 1, 000 grain weight. No definite relations were found along with locations. 8) In the varieties tested, the higher milling rate was found in large grain variety, Yungkwang, and the lowest milling rate was obtained from Suke ＃ 169, the small grain variety. But the small grained hard wheat variety such as Caprock and NB 68513 showed higher milling rate compared with the soft wheat variety, Suke ＃ 169. 9) There were no great differences of ash content due to location, fertilizer level and seeding date while remarkable differences due to variety were found. The ash content was high in the hard wheat varieties such as NB 68513, Caprock and low in soft wheat varieties such as Yungkwang and Suke ＃ 169. 3. Protein content: 10) The protein content was increased under the condition of high temperature, low humidity and shading, which were responsible for reduction of 1, 000 grain weight. The varietal differences of protein content due to high temperature, low humidity and shading conditions were greater in Yungkwang than in NB 68513. 11) The high content of protein in grain within one to two weeks after flowering might be due to the high ratio of pericarp and embryo to endosperm. As grains ripen, the effects of embryo and pericarp on protein content were decreased, reducing protein content. However, the protein content was getting increased from three or four weeks after flowering, and maximized at seven weeks after flowering. The protein content of grain at three to four weeks after flowering increased as the increase of 1, 000 grain weight. But the protein content of matured grain appeared to be affected by daily temperature on calender rather than by duration of ripening period. 12) Highly significant positive correlation value was found between the grain protein content and flour protein content. 13) The protein content was increased under the high level of fertilizers and late seeding. The local differences of protein content were greater in Suwon than in Kwangju and Iri. 14) Protein content in the varieties tested were high in Yungkwang, NB 68513 and Caprock, and low in Suke ＃ 169. However, variation in protein content due to the cultural methods was low in Suke ＃ 169. 15) Protein yield per unit area was increased in accordance with increase of fertilizer levels and early maturing culture. However, nitrogen fertilizer was utilized rather effectively in early maturing culture and Yungkwang was the highest in protein yield per unit area. 4. Physio-chemical properties of wheat flour: 16) Sedimentation value was higher under the conditions of high temperature, low humidity and high levels of fertilizers than under the conditions of low temperature, high moisture and low levels of fertilizers. Such differences of sedimentation values were more apparent in NB 68513 and Caprock than Yungkwang and Suke ＃ 169. The local difference of sedimentation value was greater in Suwon than in Kwangju and Iri. Even though the sedimentation value was highly correlated with protein content of grain, the high humidity was considered one of the factors affecting sedimentation value. 17) Changes of Pelshenke values due to the differences of cultural practices and locations were generally coincident with sedimentation values. 18) The mixing time required for mixogram was four to six minutes in NB 68513, five to seven minutes in Cap rock. The great variation of mixing time for Yungkwang and Suke ＃ 169 due to location and planting conditions was found. The mixing height and area were high in hard wheat than in soft wheat. Variation of protein content due to cultural methods were inconsistent. However, the pattern of mixogram were very much same regardless the treatments applied. With this regard, it could be concluded that the mixogram is a kind of method expressing the specific character of the variety. 19) Even though the milling property of NB 68513 and Caprock was deteriorated under either high temperature and low humidity of high fertilizer levels and late seeding conditions, baking quality was better due to improved physio-chemical properties of flour. In contrast, early maturing culture deteriorated physio-chemical properties, milling property of grain and grain protein yield per unit area was increased. However, it might be concluded that the hard wheat production of NB 68513 and Caprock for baking purpose could be done better in Suwon than in Iri or Kwangju area. 5. Interrelationships between the physio-chemical characters of wheat flour: 20) Physio-chemical properties of flour didn't have direct relationship with milling rate and ash content. Low grain weight produced high protein content and better physio-chemical flour properties. 21) In hard wheat varieties like NB 68513 and Caprock, protein content was significantly correlated with sedimentation value, Pelshenke value and mixing height. However, gluten strength and baking quality were improved by the increased protein content. In Yungkwang and Suk ＃ 169, protein content was correlated with sedimentation value, but no correlations were found with Pelshenke value and mixing height. Consequently, increase of protein content didn't improve the gluten strength in soft wheat. 22) The highly significant relationships between protein content and gluten strength and sedimentation . value, and between Pelshenke value, mixogram and gluten strength indicated that the determination of mixogram and Pelshenke value are useful for de terming soft and hard type of varieties. Determination of sedimentation value is considered useful method for quality evaluation of wheat grain under different cultural practices.