• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.436-445
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• 2023

Methane (CH₄) emissions from rice paddies are mainly observed using the closed chamber method or the eddy covariance method. In this study, a new observation technique combining a portable gas analyzer (Model LI-7810, LI-COR, Inc., USA) and an automatic opening/closing chamber (Model Smart Chamber, LI-COR, Inc., USA) was introduced based on the strengths and weaknesses of the existing measurement methods. A cylindrical collar was manufactured according to the maximum growth height of rice and used as an auxiliary measurement tool. All types of measured data can be monitored in real time, and CH₄ flux is also calculated simultaneously during the measurement. After the measurement is completed, all the related data can be checked using the software called 'SoilFluxPro'. The biggest advantage of the new observation technique is that time-series changes in greenhouse gas concentrations can be immediately confirmed in the field. It can also be applied to small areas with various treatment conditions, and it is simpler to use and requires less effort for installation and maintenance than the eddy covariance system. However, there are also disadvantages in that the observation system is still expensive, requires specialized knowledge to operate, and requires a lot of manpower to install multiple collars in various observation areas and travel around them to take measurements. It is expected that the new observation technique can make a significant contribution to understanding the CH₄ emission pathways from rice paddies and quantifying the emissions from those pathways.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.449-456
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• 2023

In this study, we developed Rapid Enrichment Broth for Vibrio parahaemolyticus (REB-V), a broth capable enriching V. parahaemolyticus from 10⁰ CFU/mL to 10⁶ CFU/mL within 6 hours, which greatly facilitates the rapid detection of V. parahaemolyticus. Using a modified Gompertz model and response surface methodology, we optimized supplement sources to rapidly enrich V. parahaemolyticus. The addition of 0.003 g/10 mL of D-(+)-mannose, 0.002 g/10 mL of L-valine, and 0.002 g/10 mL of magnesium sulfate to 2% (w/v) NaCl BPW was the most effective combination of V. parahaemolyticus enrichment. Optimal V. parahaemolyticus culture conditions using REB-V were at pH 7.84 and 37℃. To confirm REB-V culture efficiency compared to 2% (w/v) NaCl BPW, we assessed the amount of enrichment achieved in 7 hours in each medium and extracted DNA samples from each culture every hour. Real-time PCR was performed using the extracted DNA to verify the applicability of this REB-V culture method to molecular diagnosis. V. parahaemolyticus was enriched to 5.452±0.151 Log CFU/mL in 2% (w/v) NaCl BPW in 7 hours, while in REB-V, it reached 7.831±0.323 Log CFU/mL. This confirmed that REB-V enriched V. parahaemolyticus to more than 10⁶ CFU/mL within 6 hours. The enrichment rate of REB-V was faster than that of 2% (w/v) NaCl BPW, and the amount of enrichment within the same time was greater than that of 2% (w/v) NaCl BPW, indicating that REB-V exhibits excellent enrichment efficiency.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.6
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• pp.13-24
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• 2022

The purpose of this study is to examine whether the existence of related personnel in KOSDAQ technology special listed firms has a signal effect on the market and affects performance when listed. The KOSDAQ technology special listing system is a system introduced to enable future growth by securing financing through corporate public offering based on the technology and marketability of technology-based startups and venture companies. As a result of analyzing 135 special technology companies listed from 2005 to 21 (excluding SPAC mergers and foreign companies) whether or not related personnel affect corporate value and listing period when they are listed, it was analyzed that the presence of related personnel did not significantly affect corporate value or listing period. The same was found in the results of the verification by reducing the scope to related personnel such as public officials and related agencies. However, under certain conditions, significant results were derived from the presence of related personnel on the listing of companies listed in special technology cases. It was found that the presence of related personnel and VC investment had a significant effect on corporate value, and in the case of bio-industry, there was a slight significant effect on the duration of listing. This study is significant in that it systematically analyzed the signal effect of the existence of related personnel for the first time for all 135 companies. In addition, as a result of the analysis, the results suggest that internalized efforts to secure technology and marketability are more important, such as parallel to VC investment, rather than simply recruiting related personnel.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.87-92
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• 2024

'Miha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2019. The 'Miha' cultivar originates from a 2014 cross between 'Monterey' and 'Saebong No. 3', both of which exhibited excellent ever-bearing characteristics, including continuous flowering and large fruits under long-day and high temperature conditions. This new cultivar was initially named 'Saebong No. 12' after examining its characteristics and productivity during summer cultivation between 2015 and 2019. After regional adaptability tests, 'Miha' was selected from 'Saebong No. 12' as an elite cultivar. The general characteristics of 'Miha' include intermediate, elliptic leaves, and strong growth. The fruits are conical and of a dark-red color. The number of leaves of 'Miha' was 21.9, which was 6.2 fewer than that of the control cultivar, 'Goha' with 28.1. The number of flower clusters of 'Miha' was similar to that of 'Goha'. The average fruit weight of 'Miha' was 13.4 g, which was 4.3 g heavier than that of 'Goha'. The fruit hardness of 'Miha' was 36.2 g·mm^-2, which was 10.1 g·mm^-2 harder than that of 'Goha'. The marketable yield of 'Miha' was 37,393 kg·ha^-1, 156% more than that of 'Goha' with 23,970 kg·ha^-1. Therefore, the new cultivar of ever-bearing strawberry 'Miha' is expected to be very popular in the export or bakery market because it is hard.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.236-245
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• 2023

We investigated the basic vegetative phase (BVP), photoperiod-sensitivity (PS), and thermo-sensitivity (TS) of 40 rice varieties to characterize their heading ecology that is adaptable to North Korean rice production areas. The ranges were 12 - 43 days for BVP, 0 - 74 days for PS, and 15 - 33 days for TS, depending on the variety. The number of days from transplanting to the heading stage (DTH) was significantly correlated with PS in the 13 major rice production regions where all 40 varieties (including early-, middle-, and mid-late-maturing varieties) were tested. DTH was significantly correlated with BVP and TS but not with PS in the 10 low-temperature regions where only 28 early-maturing varieties were tested. The heading ecology of the adaptable varieties for each region could be characterized by an exponential equation between the BVP and PS of varieties that headed at the border of the safe marginal heading date (SMHD) for each of the seven regional environments (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, and Pyongyang). A PS of 25 - 30 days or less was an additional adaptive trait in the Sariwon and Pyongyang environments. The varieties that reached the heading stage not later than the SMHD in six regional environments (Anju, Kusong, Sinuiju, Changjon, Wonsan, and Supung) and those that reached the heading stage not later than the late marginal heading date (LMHD) in four regional environments (Hamhung, Pyonggang, Huichon, and Kanggye) had both a PS of 26 days or less and a BVP of 25 - 28 days or less. In the Yangdok, Sinpo, and Chunggang environments, varieties that reached the heading stage not later than the LMHD for each region had a BVP of 15 - 20 days or less. The results suggested that a shortened BVP trait should be introduced to existing early-maturing rice varieties to reduce the duration of growth period to reach the heading stage.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.386-391
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• 2024

'Jinha' is a new strawberry (Fragaria × ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2019. The 'Jinha' cultivar originates from a 2011 cross between 'Albion' and 'Goha,' both of which exhibited excellent ever-bearing characteristics, including continuous flowering and large fruits under long-day and high temperature conditions. This new cultivar was initially named 'Saebong No. 11' after examining its characteristics and productivity during summer cultivation between 2012 and 2016. After regional adaptability tests, 'Jinha' was selected from 'Saebong No. 11' as an elite cultivar. The general characteristics of 'Jinha' include intermediate, elliptic leaves, and medium growth. The fruits are conical and of a red color. The plant height of 'Jinha' is simiar to that of the control variety, 'Flamenco', but it has a lot of number of leaves. The cluster length of 'Jinha' was 35.5 cm, 10.8 cm longer than 24.7 cm of the control variety. The number of flower clusters of 'Jinha' appeared 14.4, which was 4.1 more than that of 'Flamenco'. The average fruit weight of 'Jinha' was 10.1 g, which was 0.8 g heavier than that of 'Flamenco'. The soluble solid content of 'Jinha' was 10.2 °Brix, which was 2.0 °Brix higher than that of 'Flamenco'. The marketable yield of 'Jinha' was 25,931 kg·ha^-1, 440% more than that of 'Flamenco' with 5,900 kg·ha^-1. Therefore, the new cultivar of ever-bearing strawberry 'Jinha' is expected to be very popular in the export or bakery market because it is high soluble solid content and good shape.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.2
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• pp.131-139
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• 2024

In Korea, mackerel is the most preferred red fish commodity and has been increasingly consumed in chillstored fresh state rather than in frozen or salted fish. Modified atmosphere packaging (MAP) technology as a replacement of air with low O₂ and high CO₂ concentration gas was applied in this study to preserve its freshness. Four MAP conditions of CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) were compared in quality preservation effect with air package used as Control. Three hundred grams mackerel fillets packaged in gas barrier tray were stored for duration of 10 days at 5℃. Quality was assessed in total aerobic bacterial count, pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid-reactive substances (TBARS), peroxide value (POV), texture, and surface color. High CO₂ concentration MAPs (CO₂(60):O₂(30):N₂(10), CO₂(60):O₂(5):N₂(35), and CO₂(60):O₂(0): N₂(40)) inhibited total aerobic bacteria growth in the fish fillets. MAPs of high CO₂ concentration with O₂ containment (CO₂(60):O₂(30):N₂(10) and CO₂(60):O₂(5):N₂(35)) showed a low TVB-N content through the storage. The treatments containing O₂ above 20% (Control and CO₂(60):O₂(30):N₂(10)) showed more accelerated increases in TBARS and POV than other treatments. The visual appearance was better for fillets in the packages of CO₂(60):O₂(5):N₂(35), CO₂(60):O₂(0):N₂(40), and CO₂(30):O₂(0):N₂(70) than for those of other treatments. The MAPs of CO₂(60):O₂(5):N₂(35) and CO₂(60):O₂(0):N₂(40) are expected to be effective in keeping the freshness of mackerel fillets.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.283-316
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• 1977

In an attempt to obtain a basic information to develop an effective integrated system of controlling sheath blight of rice in Korea, the transition of this disease, the variation of cultural characters and pathogenicity of the pathogen, environmental conditions affecting the disease outbreak and varietal resistance have been investigated. 1. Rice sheath blight which has been minor disease in the past was widely spread, especially since 1971. This disease has promptly spread all over the country and infected 65.2% of total rice growing area in 1976. Various factors are considered to be related to such transition of this disease. Above all, increace of application of nitrogenous fertilizer, early season and earlier cultivation of rice, introduction of more susceptible "Tongil" varieties etc. must be important factors influencing the outbreak of this disease. 2. Great variations in cultural characteristics-such as mycelial growth rate, color of the medium, amount of the aerial mycelium, shape and color of the sclerotia- and in the pathogenicity of isolates of the pathogen, Thanatephorus cucumeris Dank were observed. The optimum temperature for mycelial growth also varied with isolates, from $25^{\circ}C$ to $30^{\circ}C$. There were not necessarily any correlation between curtural characteristics and pathogenicity of isolates of Thanatephorus cucumens. 3. Mycelial grow th of isolates of Thanatephorus cucumens on the PDA medium were correlated with the air temperatures of the region where the isolates were collected. The isolates from the regions with high temperature grew well on PDA medium at $35^{\circ}C$ than those from the region with low temperature, on the other hand, the isolates from the regions with the low temperature grew well on the same medium at $12^{\circ}C$ than those from the regions with high temperature. 4. Pectin polygalacturonase (PG) and cellulase (Cx) were most active on the 3rd day after inoculation on the leaves of rice plant with Thanatephorus cucumeris, whereas pectin methylestrase (PE) was most active on the 4th day after inoculation. Relationship between the activities of PE of isolates and the strength of pathogenicity of isolates was obtained, but PG and cellulase activities were not correlated with pathogenicity of isolates. 5. The tolerence of sclerotia from in-vitro culture to low temperature varied with their water content, the dried cultural sclerotia were more tolerent than wet ones, Dried cultural sclerotia maintained almost 100% germinability for 45 days at $-20^{\circ}C$, whereas wet sclerotia lost viability at $-5^{\circ}C$. The germination ratio of the sclerotia after overwintering changed from 18% to 70% according to the water content of the test paddy fields and the ratio was low in wet paddy condition. 6. To investigate the host range of this fungi in and near paddy field, 17 weeds were inoculated with fungi. The lesions of sheath blight disease was obserbed on Sagittaria trifolia L., Echinochloa crusgalli P. Beauv., Monochoria vaginal is Presl, Polygonum Hydropiper L., Eclipta prostrata L., Digitaria sanguinalis Scapoli. 7. When the level of nitrogen applied was doubled over standard level, total nitrogen content in rice sheath increased, ami when silicate was applied, starch content in rice sheath decreased, inducing the rice plants more susceptible to sheath blight disease. Increased dressing of potash ferilizer reduced the incidence of sheat blight disease. 8. The percentage of infected stems in the early period increased more in the narrow hill plot than in the wide hill plot, but in the late period this tendency was inversed; the percentage of infected stems as well as severity in the wide hill plot increased more compared to the narrow hill plot, and the disease severity in the one plant per hill plot was also low. The number of stems in the wide hill plot was more than the number of stems in the narrow hill plot. This indicates that the microclimate, such as the relative humidity, in the narrow hill plot was more favorable for the development of this disease. 9. There was a high negative correlation between the disease severity of varieties to the sheath blight and the maturity of the varieties, that is, the early varieties were more susceptible than the late ones, and much-tillering varieties usually showed more infection than less tillering varieties. 10. No relationship was obtained between the percentage of infected stems in the early period and the severity after heading, whereas a distinct relationship was obtained between former and latter after Aug. 10.

• Journal of Distribution Research
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• v.15 no.1
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• pp.49-71
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• 2010

Franchise businesses in South Korea have contributed to economic growth and job creation, and its growth potential remains very high. However, despite such virtues, domestic franchise businesses face many problems such as the instability of franchisor's business structure and weak financial conditions. To solve these problems, the government enacted legislation and strengthened franchise related laws. However, the strengthening of laws regulating franchisors had many side effects that interrupted the development of the franchise business. For example, legal regulations regarding franchisors have had the effect of suppressing the franchisor's leadership activities (e.g. activities such as the ability to advocate the franchisor's policies and strategies to the franchisees, in order to facilitate change and innovation). One of the main goals of the franchise business is to build cooperation between the franchisor and the franchisee for their combined success. However, franchisees can refuse to follow the franchisor's strategies because of the current state of franchise-related law and government policy. The purpose of this study to explore the effects of franchisor's leadership style on franchisee's commitment in a franchise system. We classified leadership styles according to the path-goal theory (House & Mitchell, 1974), and it was hypothesized and tested that the four leadership styles proposed by the path-goal theory (i.e. directive, supportive, participative and achievement-oriented leadership) have different effects on franchisee's commitment. Another purpose of this study to explore the how the level of franchisee's self-efficacy influences both the franchisor's leadership style and franchisee's commitment in a franchise system. Results of the present study are expected to provide important theoretical and practical implications as to the role of franchisor's leadership style, as restricted by government regulations and the franchisee's self-efficacy, which could be needed to improve the quality of the long-term relationship between the franchisor and franchisee. Quoted by Northouse(2007), one problem regarding the investigation of leadership is that there are almost as many different definitions of leadership as there are people who have tried to define it. But despite the multitude of ways in which leadership has been conceptualized, the following components can be identified as central to the phenomenon: (a) leadership is a process, (b) leadership involves influence, (c) leadership occurs in a group context, and (d) leadership involves goal attainment. Based on these components, in this study leadership is defined as a process whereby franchisor's influences a group of franchisee' to achieve a common goal. Focusing on this definition, the path-goal theory is about how leaders motivate subordinates to accomplish designated goals. Drawing heavily from research on what motivates employees, path-goal theory first appeared in the leadership literature in the early 1970s in the works of Evans (1970), House (1971), House and Dessler (1974), and House and Mitchell (1974). The stated goal of this leadership theory is to enhance employee performance and employee satisfaction by focusing on employee motivation. In brief, path-goal theory is designed to explain how leaders can help subordinates along the path to their goals by selecting specific behaviors that are best suited to subordinates' needs and to the situation in which subordinates are working (Northouse, 2007). House & Mitchell(1974) predicted that although many different leadership behaviors could have been selected to be a part of path-goal theory, this approach has so far examined directive, supportive, participative, and achievement-oriented leadership behaviors. And they suggested that leaders may exhibit any or all of these four styles with various subordinates and in different situations. However, due to restrictive government regulations, franchisors are not in a position to change their leadership style to suit their circumstances. In addition, quoted by Northouse(2007), ssubordinate characteristics determine how a leader's behavior is interpreted by subordinates in a given work context. Many researchers have focused on subordinates' needs for affiliation, preferences for structure, desires for control, and self-perceived level of task ability. In this study, we have focused on the self-perceived level of task ability, namely, the franchisee's self-efficacy. According to Bandura (1977), self-efficacy is chiefly defined as the personal attitude of one's ability to accomplish concrete tasks. Therefore, it is not an indicator of one's actual abilities, but an opinion of the extent of how one can use that ability. Thus, the judgment of maintain franchisee's commitment depends on the situation (e.g., government regulation and policy and leadership style of franchisor) and how it affects one's ability to mobilize resources to deal with the task, so even if people possess the same ability, there may be differences in self-efficacy. Figure 1 illustrates the model investigated in this study. In this model, it was hypothesized that leadership styles would affect the franchisee's commitment, and self-efficacy would moderate the relationship between leadership style and franchisee's commitment. Theoretically, quoted by Northouse(2007), the path-goal approach suggests that leaders need to choose a leadership style that best fits the needs of subordinates and the work they are doing. According to House & Mitchell (1974), the theory predicts that a directive style of leadership is best in situations in which subordinates are dogmatic and authoritarian, the task demands are ambiguous, and the organizational rule and procedures are unclear. In these situations, franchisor's directive leadership complements the work by providing guidance and psychological structure for franchisees. For work that is structured, unsatisfying, or frustrating, path-goal theory suggests that leaders should use a supportive style. Franchisor's Supportive leadership offers a sense of human touch for franchisees engaged in mundane, mechanized activity. Franchisor's participative leadership is considered best when a task is ambiguous because participation gives greater clarity to how certain paths lead to certain goals; it helps subordinates learn what actions leads to what outcome. Furthermore, House & Mitchell(1974) predicts that achievement-oriented leadership is most effective in settings in which subordinates are required to perform ambiguous tasks. Marsh and O'Neill (1984) tested the idea that organizational members' anger and decline in performance is caused by deficiencies in their level of effort and found that self-efficacy promotes accomplishment, decreases stress and negative consequences like depression and emotional instability. Based on the extant empirical findings and theoretical reasoning, we posit positive and strong relationships between the franchisor's leadership styles and the franchisee's commitment. Furthermore, the level of franchisee's self-efficacy was thought to maintain their commitment. The questionnaires sent to participants consisted of the following measures; leadership style was assessed using a 20 item 7-point likert scale developed by Indvik (1985), self-efficacy was assessed using a 24 item 6-point likert scale developed by Bandura (1977), and commitment was assessed using a 6 item 5-point likert scale developed by Morgan & Hunt (1994). Questionnaires were distributed to Korean optical franchisees in Seoul. It took about 20 days to complete the data collection. A total number of 140 questionnaires were returned and complete data were available from 137 respondents. Results of multiple regression analyses testing the relationships between the each of the four styles of leadership shown by the franchisor as independent variables and franchisee's commitment as the dependent variable showed that the relationship between supportive leadership style and commitment ($\beta$=.13, p<.001),and the relationship between participative leadership style and commitment ($\beta$=.07, p<.001)were significant. However, when participants divided into high and low self-efficacy groups, results of multiple regression analyses showed that only the relationship between achievement-oriented leadership style and commitment ($\beta$=.14, p<.001) was significant in the high self-efficacy group. In the low self-efficacy group, the relationship between supportive leadership style and commitment ($\beta$=.17, p<.001),and the relationship between participative leadership style and commitment ($\beta$=.10, p<.001) were significant. The study focused on the franchisee's self-efficacy in order to explore the possibility that regulation, originally intended to protect the franchisee, may not be the most effective method to maintain the relationships in a franchise business. The key results of the data analysis regarding the moderating role of self-efficacy between leadership behavior style as proposed by path-goal and commitment theory were as follows. First, this study proposed that franchisor should apply the appropriate type of leadership behavior to strengthen the franchisees commitment because the results demonstrated that supportive and participative leadership styles by the franchisors have a positive influence on the franchisee's level of commitment. Second, it is desirable for franchisor to validate the franchisee's efforts, since the franchisee's characteristics such as self-efficacy had a substantial, positive effect on the franchisee's commitment as well as being a meaningful moderator between leadership and commitment. Third, the results as a whole imply that the government should provide institutional support, namely to put the franchisor in a position to clearly identify the characteristics of their franchisees and provide reasonable means to administer the franchisees to achieve the company's goal.