• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.4
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• pp.23-44
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• 1988

The evaportranspiration of upland crops was measured by four types of lysimeter and water consumption characteristics together with the optimum irrigation point by the crops was defind. Among the evapotranspiration estimation formulas, the constant of wind function in the modified Penman equation was corrected to agree with the meteorological conditions of Korea. The evapotranspiration of the crops in the project standard year was estimated according to the cropping system of the project area in Chungju, and from the estimated evapotras - spiration, net duty of water per one time and irrigation in tervals were investigated. The results obtained are summarized as follows: 1. The evapotranspiration of the same crop measured at the same plot was slightly different by the lysimetric methods, and among the four types of lysimeter, the accuracy of the floating lysimeter was the highest. 2. The yields among the watering treatments showed the significance of 5% in the expe- riment with red cabbage and Chinese cabbage, and significance of 1% in the crisphead lettuce, and the optimum irrigation point for the tested crops was defined ad pF 2.0 by the least squre difference test. 3. The evapotranspiration of the crops in the mid-season stage showed maximum among the growing stages, and the average daily evapotranspiration by the crops over the growing seasons of cabbage, crisphead lettuce, Chinese cabbage, summer cucumber, tornato, salary and autumn cucumber was 4.18mm, 4.77mm, 3.9qrnm, 5.68mnn, joonim, 4.26mm and 3.3qrnn, respectively. 4. From the investigated soil moisture extration pattern(SMEP) of the crisphead lettuce, cucumber and tomato, the proportion of the first layer in the initial stage showed over so%, and the SMEP of the lowest fourth layer during the late-season stage in the experiment cabbage and Chinese cabbage was 15.8% and 16.9, respectively, with showed that the root elongated th the lowest soil layer. 5. The total available moisture(TAM) of clay loam was 21.2-23.3mm and that of sandy loam was 16.1 - 19.0mm under the optimum irrigation point of pF. 2.0, and the total readily available moisture( TRAM) of the crops cultivated in the clay loam soil was larger than that cultivated in the sandy loam soil, and the TRAM during the mid-and late-season were larger than that of the inital and crop development stage. 6. The estimated evapotranspration by the corrected Pennam equation, whkh corrected the constant of the wind function in the modified Penman equation, was nearly agreed with the actually measured evaporanspiration of grass. 7. Among the several evaportranspiration estimation methods, the evapotranspiration es- timated by the corrected Pennam equation was closed to the actual evapotranspiration of reference crop (grass) evapotranspiration, therefore it is suggested to use the corrected Penman equation to determine the duty of water of corps. 8. The average crop coefficient (Kc) of cabbage by the corrected Penman equation was 0.94 and that of crisphead lettuce, summer cucumber, tomato, salary, Chinese cabbage and autumn cucumber was 1.07, 1.22, 1.02, 1.01, 1.35, 1.09, respectively 9. The estimated total evapotranspiration of cabbage in the project area( Chungju) by the corrected Penman equation was 223.9mm and that of crisphead lettuce, Chinese cabbage, summer cucumber, tomato, salary and auturun cucumber was 215.7mm, 205.9mm, 359.Omrn, 300.9mm, 332.lmm and 202.7mm, respectively. 10. The net duty of water per one time of the crops cultivated in the sandy loam soil, and the net duty of water per one time in the mid-season & late-season showed larger than that of the initial stage. 11. The shortest irrigation interval of cabbage in the project area was 4.2 days, and that of crisphead lettuce, Chinese cabbage, cucumber, tomato and salary was 1.2days, 2.3days, 1.8days, 2.2days and 2.7days, respectively.

• Food Science and Preservation
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• v.19 no.5
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• pp.783-791
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• 2012

The purpose of the study was to provide baseline information that could encourage consumers and establish the direction of development for sprouts and leafy vegetables. A survey on the consumption and preference for sprouts and leafy vegetables of 823 people over 20 years of age in Seoul and Gyeonggi province was conducted. The preference for sprouts was higher in men ($3.75{\pm}0.96$) than in women ($3.64{\pm}0.84$), whereas the preference for leafy vegetables was higher in women ($4.06{\pm}0.74$) than in men ($3.88{\pm}0.90$). Based on age, the respondents in their 40s or above had high preferences for sprouts and leaf vegetables due to the importance that they accorded to health and nutrition (p<0.01). The sprouts and leafy vegetables were purchased mainly for their high nutritional value. The purchase frequency of once a month or more for leafy vegetables (82.7%) was higher than that for sprouts (57.1%). The consumers purchased sprouts and leafy vegetables mainly from a large discount store. The respondents in their 20s showed the highest percentage of purchasing from a local store whereas the older ones showed a high preference for traditional markets. The reason for the choice of the place of purchase was convenience. The freshness and price were important factors in the consumption of sprouts and leafy vegetables. In the case of leafy vegetables, the consumers preferred to buy them using the conventional weight measurement system rather than in small packages. On the other hand, mixed small packages were preferred for sprouts. The purchase frequency was correlated with the preferences, need for improvement and purchase intent for sprouts and leafy vegetables. The aspects that require improvement for producing high-quality sprouts and leafy vegetables were the nutritional and functional properties. To increase the consumption of sprouts and leafy vegetables, there is need for variations and improvement of the quality and safety of the products.

• Korean Journal of Optics and Photonics
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• v.27 no.1
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• pp.18-24
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• 2016

To effectively utilize a flash and predict its effects on an infrared device, it is essential to know the infrared characteristics of the flash source. In this paper, a study of the IR characteristics of flash light sources is carried out. The IR characteristics of three flash sources, of which two are combustive and the other is explosive, are measured with an IR characteristic measurement system over the middle- and long-wavelength infrared ranges. From the measurements, the radiances over the two IR ranges and the radiative temperatures of the flashes are extracted. The IR radiance of flash A is found to be the strongest among the three, followed by those of sources C and B. It is also shown that the IR radiance of flash A is about 10 times stronger than that of flash B, even though these two sources are the same type of flash with the same powder. This means that the IR radiance intensity of a combustive flash source depends only on the amount of powder, not on the characteristics of the powder. From the measured radiance over MWIR and LWIR ranges for each flashes, the radiative temperatures of the flashes are extracted by fitting the measured data to blackbody radiance. The best-fit radiative temperatures (equivalent to black-body temperatures) of the three flash sources A, B, and C are 3300, 1120, and 1640 K respectively. From the radiance measurements and radiative temperatures of the three flash sources, it is shown that a combustive source radiates more IR energy than an explosive one; this mean, in turn, that the effects of a combustive flash on an IR device are more profound than those of an explosive flash source. The measured IR radiances and radiative temperatures of the flash sources in this study can be used to estimate the effects of flashes on various IR devices, and play a critical role for the modeling and simulation of the effects of a flash source on various IR devices.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.149-160
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• 2007

KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ${\sim}2.6\;t\;C\;ha^{-1}y^{-1}$. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric $CO_2$. The catchment scale water budget indicated that $30\sim40%$ of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about $12{\mu}mol\;CO_2/mmol\;H_2O$ with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

• Journal of Distribution Science
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• v.10 no.5
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• pp.45-55
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• 2012

In Korea, the parcel delivery service was launched officially in 1992, and the market has grown to 13.2 billion units, or 3.5 trillion won, as of 2011. The service companies accept small packages under 30 kg and deliver them on the next day in most domestic areas. This service plays an important role in business and personal activities. The parcel service companies have themselves designed the tariff for the delivery service based on two criteria: weight and the sum of three side lengths. Further, the tariff is graded in steps of three or four rate structures based on size (small, medium, large, and extra-small). However, the basic freight rate is generally decided according to the cargo's weight or measurement size, and an extra rate is added according to some factors (handling, stowability, liability, and so on). The parcel service tariff adopted by the companies is illogically designed, and this study was carried out to assess the need for redesigning the tariff structure. The cargo volume cannot be logically reflected by three side lengths. For example, two parcels measuring 160 cm based on three side lengths may have different volumes, one measuring 0.152 cbm (53.33 cm × 53.33 cm × 53.34 cm) and the other 0.05 cbm (100 cm × 50 cm × 10 cm). A small package of less than120 cm (sum of three side lengths) may have a volume of as much as 0.064 cbm (40 cm × 40 cm × 40 cm). Sample comparison showed that 17% of medium-size parcels (based on the sum of three side lengths) are small-volume packages, 24% of large-size parcels are small- or medium-volume packages, and 40% of extra-big-size parcels are big- or under-size packages. Therefore, if parcel service companies rate their services for volume cargo based on the three side lengths standard, users may have to pay higher than normal rates, particularly because a large percentage of parcels are volume cargo. According to this study, the average weight per 1 cbm is less than 300 kg. Therefore, users face an increasing risk of paying higher than logical freight charges. Generally, transportation companies are called "public interest enterprises," and parcel service companies operate as postal services. Public interest enterprises must provide the delivery service to all customers without discrimination at a reasonable service level and logical service charges. Therefore, parcels service tariffs must be designed and adopted logically. In this study, freight theories and prior research findings were used to consider the importance of freight rates, and distortion of parcel service rates based on the three side lengths system was verified through regression analysis of a parcel sample and sample comparison. In conclusion, volume sizes based on three side lengths have a higher correlation to the rate level than does the sum of three side lengths. Further, compared to the sum of three side lengths, volume size has a higher correlation to cargo weight, which is the most basic factor determining transportation cost. Therefore, the existing parcel service tariff should be changed to weight- and volume-based rates, and the tariff must be graded in steps of 8 to 10 higher rate structures for a logical freight schedule based on service cost.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.377-387
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• 1996

Background : In 1980, WHO made a definition in which the term "impairment" as applied to the respiratory system is used to describe loss of lung function, "disability" the resulting diminution in exercise capacity. The measurement of pulmonary function during exercise would give us information about overall functional capacity and respiratory performance that would be lacking in tests performed at rest. We conducted this study to investigate the role of resting pulmonary function test and exercise test for assessing impairment/disability in patients with chronic airflow obstruction(CAO). Method : We studied 19 patients with CAO. The spirometry and body plethysmograph were performed in stable condition. And then patients performed a progressive incremental exercise test to a symptom-limited maximum using cycle ergometer. Patients were divided in two groups, severe and non-severe impairment, according to the resting PFTs and compaired each other. A patient was considered to be severely impaired if FVC < 50 %, FEV1 < 40 % or FEV1/FVC < 40 %. Results : 1) The airway obstruction and hypoxemia of severe impairment group were more severe and exercise performance was markedly reduced compairing to non-severe impairment group. 2) The severe impairment group showed ventilatory limitation during exercise test and the limiting symptomes ware dyspnea in 9/10 patients. 3) The impairment and disability of the patients with tuberculous destructed lung were most marked in patients with CAO. 4) The FEV1 was the most prevalent criterion for the determination of severe impairment based on resting PFTs and was the valuable best correlated to V02max(r=0.81, p < 0.001). 5) The sensitivity of exercise limits for predicting severe disability according to resting PFTs was 80 % and specificity 89 %. Conclusion : In patients with severe CAO, FEV1 is a good predictive of exercise performance and impairment measured by resting PFTs can predict a disability by exercise test.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.177-192
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• 2016

Machine learning is a field of artificial intelligence. It refers to an area of computer science related to providing machines the ability to perform their own data analysis, decision making and forecasting. For example, one of the representative machine learning models is artificial neural network, which is a statistical learning algorithm inspired by the neural network structure of biology. In addition, there are other machine learning models such as decision tree model, naive bayes model and SVM(support vector machine) model. Among the machine learning models, we use SVM model in this study because it is mainly used for classification and regression analysis that fits well to our study. The core principle of SVM is to find a reasonable hyperplane that distinguishes different group in the data space. Given information about the data in any two groups, the SVM model judges to which group the new data belongs based on the hyperplane obtained from the given data set. Thus, the more the amount of meaningful data, the better the machine learning ability. In recent years, many financial experts have focused on machine learning, seeing the possibility of combining with machine learning and the financial field where vast amounts of financial data exist. Machine learning techniques have been proved to be powerful in describing the non-stationary and chaotic stock price dynamics. A lot of researches have been successfully conducted on forecasting of stock prices using machine learning algorithms. Recently, financial companies have begun to provide Robo-Advisor service, a compound word of Robot and Advisor, which can perform various financial tasks through advanced algorithms using rapidly changing huge amount of data. Robo-Adviser's main task is to advise the investors about the investor's personal investment propensity and to provide the service to manage the portfolio automatically. In this study, we propose a method of forecasting the Korean volatility index, VKOSPI, using the SVM model, which is one of the machine learning methods, and applying it to real option trading to increase the trading performance. VKOSPI is a measure of the future volatility of the KOSPI 200 index based on KOSPI 200 index option prices. VKOSPI is similar to the VIX index, which is based on S&P 500 option price in the United States. The Korea Exchange(KRX) calculates and announce the real-time VKOSPI index. VKOSPI is the same as the usual volatility and affects the option prices. The direction of VKOSPI and option prices show positive relation regardless of the option type (call and put options with various striking prices). If the volatility increases, all of the call and put option premium increases because the probability of the option's exercise possibility increases. The investor can know the rising value of the option price with respect to the volatility rising value in real time through Vega, a Black-Scholes's measurement index of an option's sensitivity to changes in the volatility. Therefore, accurate forecasting of VKOSPI movements is one of the important factors that can generate profit in option trading. In this study, we verified through real option data that the accurate forecast of VKOSPI is able to make a big profit in real option trading. To the best of our knowledge, there have been no studies on the idea of predicting the direction of VKOSPI based on machine learning and introducing the idea of applying it to actual option trading. In this study predicted daily VKOSPI changes through SVM model and then made intraday option strangle position, which gives profit as option prices reduce, only when VKOSPI is expected to decline during daytime. We analyzed the results and tested whether it is applicable to real option trading based on SVM's prediction. The results showed the prediction accuracy of VKOSPI was 57.83% on average, and the number of position entry times was 43.2 times, which is less than half of the benchmark (100 times). A small number of trading is an indicator of trading efficiency. In addition, the experiment proved that the trading performance was significantly higher than the benchmark.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.74-83
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• 2011

The high-pass transportation information system directly collects section information by using probe cars and therefore can offer more reliable information to drivers. However, because the running condition and features of probe cars and statistical processing methods affect the reliability of the information and particularly because the section travel time is greatly influenced by whether there has been delay by signals on urban roads or not, there can be much deviation among the collected individual probe data. Accordingly, researches in multilateral directions are necessary in order to enhance the credibility of the section information. Yet, the precedent studies related to high-pass information provision have been conducted on the highway sections with the feature of continuous flow, which has a limit to be applied to the urban roads with the transportational feature of an interrupted flow. Therefore, this research aims at analyzing the features of high-pass transportation data on urban roads and finding a proper processing method. When the characteristics of the high-pass data on urban roads collected from RSE were analyzed by using a time-space diagram, the collected data was proved to have a certain pattern according to the arriving cars' waiting for signals with the period of the signaling cycle of the finish node. Moreover, the number of waiting for signals and the time of waiting caused the deviation in the collected data, and it was bigger in traffic jam. The analysis result showed that it was because the increased number of waiting for signals in traffic jam caused the deviation to be offset partially. The analysis result shows that it is appropriate to use the mean of this collected data of high-pass on urban roads as its representative value to reflect the transportational features by waiting for signals, and the standard of judgment of delay and congestion needs to be changed depending on the features of signals and roads. The results of this research are expected to be the foundation stone to improve the reliability of high-pass information on urban roads.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.848-858
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• 2007

Sontag and Lee (2004) recently developed an objectively measurable instrument, the Proximity of Clothing to Self(PCS) Scale, which measured the psychological closeness of clothing to self. They validated a 4-factor, 24-item PCS Scale for use with adolescents and identified the need for confirmation of the factor structure with other age groups. This paper extends the work of Sontag and Lee by employing the PCS Scale with older persons, age 65 and over, and reports the validation of a 3-factor, 19-item PCS Scale for older persons. A mail survey was sent to a national random sample of 1,700 older Persons by means of a list purchased from a U.S. survey sampling company in late November 2004. Total usuable number of respondents was 250 with an adjusted response rate of 15.6 percent. Three analytical rounds of confirmatory factor analysis(CFA) to test the construct validity of the PCS Scale were conducted by using AMOS 5.0(Analysis of Moment Structures), one of several structural equation modeling(SEM) programs. Completion of three rounds of the CFA resulted in a 3-factor, 19-item PCS Scale with demonstrated construct validity and reliability for older persons. The three PCS dimensions are clothing in relation to 1) self as structure-process(PCS Dimension 1-2-3 combined), 2) self-esteem-evaluative and affective processes(PCS Dimension 4-5 combined), and 3) body image and body cathexis(PCS Dimension 6). The initially hypothesized 6-factor scale(Sontag & Lee, 2004) was not confirmed for adolescents in their study nor with older persons in this study. In addition, the 4-factor solution for the adolescent group did not hold for older persons. It appears that the self-system of older persons is more integrated than may be true for younger individuals. Recommendations for future testing of construct validity of the PCS Scale are made.

• Journal of radiological science and technology
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• v.39 no.1
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• pp.51-57
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• 2016

Acoustic noise during magnetic resonance imaging (MRI) is the main source for patient discomfort. we report our preliminary experience with this technique in neuroimaging with regard to subjective and objective noise levels and image quality. 60 patients(29 males, 31 females, average age of 60.1) underwent routine brain MRI with 3.0 Tesla (MAGNETOM Tim Trio; Siemens, Germany) system and 12-channel head coil. Q-$T_2$ and $T_2$ sequence were performed. Measurement of sound pressure levels (SPL) and heart rate on Q-$T_2$ and $T_2$ was performed respectively. Quantitative analysis was carried out by measuring the SNR, CNR, and SIR values of Q-$T_2$, $T_2$ and a statistical analysis was performed using independent sample T-test. Qualitative analysis was evaluated by the eyes for the overall quality image of Q-$T_2$ and $T_2$. A 5-point evaluation scale was used, including excellent(5), good(4), fair(3), poor(2), and unacceptable(1). The average noise and peak noise decreased by $15dB_A$ and $10dB_A$ on $T_2$ and Q-$T_2$ test. Also, the average value of heartbeat rate was lower in Q-$T_2$ for 120 seconds in each test, but there was no statistical significance. The quantitative analysis showed that there was no significant difference between CNR and SIR, and there was a significant difference (p<0.05) as SNR had a lower average value on Q-$T_2$. According to the qualitative analysis, the overall quality image of 59 case $T_2$ and Q-$T_2$ was evaluated as excellent at 5 points, and 1 case was evaluated as good at 4 points due to a motion artifact. Q-$T_2$ is a promising technique for acoustic noise reduction and improved patient comfort.