• Journal of Advanced Navigation Technology
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• v.4 no.2
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• pp.114-131
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• 2000

An airline should consider the number of seats or size of aircraft, when it composes fleet or selects a type of aircraft for some routes. There are two major factors considered for this choice problem under the assumption that the objectives of an airline is a profit maximization: the operating cost and revenue from the aircraft operated. This research tries to solve the problem of aircraft size selection by airline. The study applies four steps to get optimal choice of aircraft size: (1) cost analysis for the relationship between airline operation cost and aircraft size: (2) market share and revenue analysis: (3) flight segment-level analysis, based on the derived cost, demand and revenue functions: and (4) network-level analysis to see how airlines make choice of aircraft size systematically at a network level. An airline can accommodate the increasing air travel demand by either increasing operation frequency, or increasing aircraft size that is represented by seat capacity, or both. Airport runway capacity and productivity depend on the size of aircraft used at airport. This paper presents the understanding of how airlines make decisions on the size of aircraft to operate, how they will adjust their choices when airport capacity is constrained, and how public regulation such as policy for landing fees could influence airlines' aircraft choice.

• The Korean Journal of Emergency Medical Services
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• v.15 no.1
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• pp.65-78
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• 2011

Purpose : We investigated the career choice and the employment preparation of emergency medical technology (EMT) students. The results of study will provide the base information about the consciousness for career choice and employment of the EMT students. Method : We conducted 1,586 surveys from 665 students at six four-year colleges and 921 students at seven three-year colleges, from Aug. 27th to Oct. 31st in 2010. The result was analyzed by SPSS 18.0 using description statistics, t-test, ANOVA, Scheffe and Pearson correlation coefficient. Result : The general characteristics showed male 50.2% and female 49.8%, and first grade 34.6%, second grade 27.4%, third grade 28.2%, and fourth grade 9.8%. The 53.9% of students had experienced the hospital training and the 44.8% did the fire station training. For the choice of job, there were the 61.8% student who hope to enter the employ in fire station or public service, while 25.7% students hope to be employed in hospitals. The reason for a wish job were 'majors-related job' in 18.2% students, 'employment stability' in 17.2% and 'hit on the aptitude and talent' in 16.7%, 'appropriate salaries' in 15.9%. In the questionnaire of the University what to assist you for job preparation, they chose the 'support for get major related license', 'support for officer exam preparation' and 'support of foreign language study' in 34.6%, 16.8% and 16.6%, respectively. For achieved licence, they had a driver's license in 53.9%, BLS (basic life support) provider in 20.3%, life guard in 16.2% and scuba in 8.8%. The statistically significant correlation was identified between the awareness of University that provides job information and one's career awareness (r= .203, p<.000), the awareness that University provide job information and one's confidence in employment (r= .236, p<.000), and one's career awareness and one's confidence in employment (r = .356, p = .000). Conclusion : The most of EMT Students are well conscious of the their future employment and has prepared career to be employed their preference job.

• Korean Journal of Community Nutrition
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• v.24 no.4
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• pp.300-308
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• 2019

Objectives: This research was conducted to identify the consumers' food choice factors that affect the consumers' replacement of soft drinks with carbonated water. Methods: The present study used secondary data from a consumer panel survey conducted by the Rural Development Administration of Korea, and the data included the panel members' purchase records based on their monthly spending receipts. The survey asked the participants about their food choice factors and their personal responsibility for their health. This survey included independent variables for the consumers' food purchase factors. As a dependent variable, two types of groups were defined. The replacement group included those people who increased their purchase of carbonated water and decreased their purchase of soft drinks. The non-replacement group included those people who did not change their purchase patterns or they increased their purchase of soft drinks and they decreased their purchase of carbonated water. Logistic regression analysis was conducted to determine the consumers' food choice factors that were associated with replacing soft drinks with carbonated water. Results: The replacement group was significantly associated with (1) a younger age (OR=0.953), (2) being a housewife (OR=2.03), (3) higher income (OR=1.001) and (4) less concern about price (OR=0.819) when purchasing food. This group also showed (5) higher enjoyment (OR=1.328) when choosing food and (6) they took greater responsibly for their personal health (OR=1.233). Conclusions: This research is the first study to mainly focus on soft drinks and carbonated water. The result of this research showed that young, health-conscious consumers with a higher income and who are more interested in food have more possibilities to replace soft drinks with carbonated water. These research findings may be applied to consumers who have characteristics that are similar to the young health-conscious consumers and the results can help to suggest ways to reduce sugar intake and improve public health. However, this research has a limitation due to the application of secondary data. Therefore, a future study is needed to develop detailed survey questions about food choice factors and to extend these factors to all beverages, including soft drinks made with sugar substitutes, so as to reflect the growth of alternative industries that use artificial sweeteners or different types of sugar to make commercially available drinks.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.25-33
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• 2007

The local governments of major cities in Korea are giving focus on public transportation to reduce congestion and improve accessibility in city areas. In this regards, the proper measurement of accessibility is now a key policy requirement for reorganizing the public transport network. Public transport routing problems, however, are considered to be highly complicated since a multi-mode travel generates different combinations of accessibility. While most of the previous research efforts on measuring transport accessibility are found at zone-levels, an alternative approach at a finer scale such as bus links and stops is presented in this study. We proposes a method to compute the optimal route choice of origin-destination pairs and measure the accessibility of the chosen modes combination based on topological configuration. The genetic algorithm is used for the computation of the journey paths, whereas the space syntax theory is used for the accessibility. This study used node-link data in GIS instead of axial lines which are manually drawn in space syntax. The resulting accessibilities of bus stops are calibrated by O-D survey data and the proposed process is tested on a CBD of Seoul.

• Korea Journal of Hospital Management
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• v.21 no.4
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• pp.13-22
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• 2016

목적: 이 연구는 당뇨와 고혈압 환자의 상급종합병원 이용에 미치는 요인을 관찰하였다. 방법: 이 연구는 한국보건사회연구원과 국민건강보험공단이 공동으로 조사하는 한국의료패널 자료를 사용하였다(2008년, 2010년, 2012년). 연구대상은 20세 이상 성인이었으며 각 2008년에 2409명, 2010년에 2424명, 2012년에 2429명을 관찰하였다. 당뇨와 고혈압에 대한 외래방문 건수는 총 64,438건이었으며 당뇨 또는 고혈압 환자의 3차 의료기관 선택에 영향을 주는 요인을 관찰하기 위해 다수준 로지스틱 회귀분석을 활용하였다. 결과: 교육수준이 높은 환자가 낮은 환자에 비해 상급종합병원을 이용할 확률이 각각 2008년에 2.04배, 2010년에 1.83배, 그리고 2012년에 1.65배 더 높았다. 또한 고소득 환자가 저소득 환자에 비해 3차 의료기관을 이용할 확률이 2008년에 1.77배, 2010년 1.91배 그리고 2012년 1.94배 더 높았다. 결론: 정책입안자들은 의료전달 시스템과 관련하여 정책을 실행할 때 이러한 환자의 특징을 고려할 필요가 있다.

• Environmental and Resource Economics Review
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• v.30 no.3
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• pp.395-433
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• 2021

This paper aims to examine the effects of homeownership and residential types on the economic values of urban green spaces. Green open spaces as public goods provide positive externalities that are comprised of pecuniary and technological externalities. Seoul, South Korea, is used as a case study using choice experiments, with split-sample online respondents of 1,000. The study results evidenced that the differentiation between the two types of externalities is imperative for equitable provisions and efficient management of various urban open spaces. There is a positively significant and substantial impact of homeownership for apartment dwellers, ceteris paribus, but not for house dwellers. For apartments, the efficiency loss can be reduced by increasing green spaces up to the critical point where the marginal cost is at equilibrium with tenants' marginal values. For non-apartment houses, it is not homeownership but the monthly household income that has a significant impact on the amenity value. In general, public benefits from green spaces are equivalent to 16% to 33% of the current residential prices on average for a view or access. Different residential types do not cause a significant impact on the access values. Residential profiles for green spaces were developed, together with tailor-made policy suggestions.

• Korean Business Review
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• v.20 no.2
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• pp.29-45
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• 2007

In today's rapidly changing business environment, corporations need to have flexibility in order to survive. This was especially true of Korean firms that were affected by the policies of the International Monetary Fund(IMF) since 1997. IMF requirements became a catalyst that helped Korean firms design their HR practices more rational and efficient. Although these changes increased the firms flexibility and global competitiveness, they also brought some harmful effects. Job insecurity is one of the most serious problems in Korean firms and in the greater Korean society, As today's organizations no longer lifelong employment, individuals put stress on psychological satisfaction with the need to manage one's career and employability in the open labor market rather than rapid promotion or high compensation in a organizations. Theoretically and empirically, the topics of career choice and career development were extensively developed. On the other hand, the issue of career commitment received little attention. The purpose of this study is to examine the preceding factors career commitment among public officials in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.214-222
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• 2001

A precise echosounding system to investigate the topographical characteristics of the coastal fishing ground was composed of a public-DGPS receiver, a single beam echosounder and a survey software. To confirm the usefulness of the system, a set-net fishing ground and the distribution of artificial reefs were surveyed. The results obtained are as follows : 1. The 2-D positioning error of the public-DGPS receiver with a DGPS mode and a GPS mode was 5.47 m, 7.03 m, respectively. 2. The experimented set-net fishing ground was located on the level ground at the depth of 9-10 m, a small size valley 1-2 m deep and approximately 10 m wide was found at a distance of 120 m from the set-net to the south. 3. In the artificial reefs' water area near the Jaran Bay, it was confirmed that twenty rectangular artificial reefs were established by the piece at the depth of 15-25 m and a natural reef 5-8 m high on the sea bed was located near the group of artificial reefs. 4. It was confirmed that the precise echosounding system was a useful tool in the pre-study to choice an appropriate water area to provide the artificial reef.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3231-3249
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• 2014

Deniable encryption, introduced in 1997 by Canetti, Dwork, Naor, and Ostrovsky, guarantees that the sender or the receiver of a secret message is able to "fake" the message encrypted in a specific ciphertext in the presence of a coercing adversary, without the adversary detecting that he was not given the real message. Sender - side deniable encryption scheme is considered to be one of the classification of deniable encryption technique which defined as resilient against coercing the sender. M. H. Ibrahim presented a sender - side deniable encryption scheme which based on public key and uncertainty of Jacobi Symbol [6]. This scheme has several problems; (1) it can't be able to derive the fake message $M_f$ that belongs to a valid message set, (2) it is not secure against Quadratic Residue Problem (QRP), and (3) the decryption process is very slow because it is based dramatically on square root computation until reach the message as a Quadratic Non Residue (QNR). The first problem is solved by J. Howlader and S. Basu's scheme [7]; they presented a sender side encryption scheme that allows the sender to present a fake message $M_f$ from a valid message set, but it still suffers from the last two mentioned problems. In this paper we present a new sender-side deniable public-key encryption scheme with fast decryption by which the sender is able to lie about the encrypted message to a coercer and hence escape coercion. While the receiver is able to decrypt for the true message, the sender has the ability to open a fake message of his choice to the coercer which, when verified, gives the same ciphertext as the true message. Compared with both Ibrahim's scheme and J. Howlader and S. Basu's scheme, our scheme enjoys nice two features which solved the mentioned problems: (1) It is semantically secure against Quadratic Residue Problem; (2) It is as fast, in the decryption process, as other schemes. Finally, applying the proposed deniable encryption, we originally give a coercion resistant internet voting model without physical assumptions.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.13-22
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• 2019

In the midst of the rapid changes in the digital media environment, this study try to examine the challenges of the public service broadcasting(PSB) news as a representative public sphere in a democratic society, and sought realistic alternatives through a case study of the BBC, one of the most successful digital policies of PSB in the world. The study found that the BBC's 'Digital First' strategy pursued a fundamental change in news formats, thereby simultaneously innovating on content. It was also interesting to see that the news consumers' needs for social media and video content were selectively analyzed and approached with a strategy of choice and focus. Finally, the production of customized digital content by analyzing news viewing behavior by each age group also suggests a lot to Korean PSB. I hope that the cases of this study will be reflected in the digital policies of Korean PSB.